*Expensive* piece of sh*t, let's get technical here. @NurdRage: Your repair work may be amateurish, but it's lightyears ahead of the best that 9/10 people who use electronics could do. And hey, if it works, it works!
I'm usually the guy that fixes everything in the lab so this is great to see. Good to know something like this can be fixed instead of breaking the bank.
I have never seen a hot plate stirrer look so clean and nice inside during a repair. The ones I worked on were used for acid digestion, mainly aqua regia, and were brown rust puffs inside. Great to see one repaired without too much trouble.
True - while at the same time beeing scared that this bloody thing failed hot. How did this device pass the design review phase? If the heating fails for any reason, it should fail safe, meaning the hot plate should not heat any more. I don't want to imagine the damage this hot plate can cause, when it over cocks/boils chemicals. After seeing this, I would add an emergency off to the lab just in case. That in the chemistry world devices get sold that aren't safe to use is scary. (Well, until I think about my former job -we had safty engineers with blinkers (those for horses) on. They where unable to find a safety concern unless specifically told...)
Considering the Triac is switching mains, I would not call that a repair. The solderblob on one of the legs makes the distance between the pins alot smaller than it should be. That's another short waiting to happen, especially in a lab environment where you create vapors of not only water but most likely also other chemicals that create conductive layers on condensation.
that hot plate fucks him up....in last video where he made a probe for it he started cursing even more it's normal... piece or shit is piece of shit ...i sometimes get really angry too....like if you need to print smth. important and that stupid printer dosen't work...or worse, it's empty....
Electrical Engineer here: the reason why is that power supply is flapping in the breeze is that it's a piece of sh!t. Cheap products don't have a lot of engineering in them, because engineering (and giving a sh!t about the design in general) costs money. Chinese knockoff vendors don't spend money... in fact they often will start pulling parts until it quits working, and then puts the last part back and calls it good. They only care about lowest price, safety, reliability, and quality be damned. Edit- the reason they have two supplies in the first place is to ensure that the microcontroller (and any other logic/control circuitry) gets nice clean power... motors tend to make supply rails noisy, and the proper supplies for such are optimized more for power output, not lack of noise. I know you probably paid a decent chunk of change for that unit, but that build quality just makes my skin crawl.
+Larry Bolan ah interesting! Thanks for explaining. You think it would be a good idea for me to secure the dangling power supply with some electrical tape? I'm wondering if it hitting something conductive was what made it fail to begin with.
Your best bet is to apply hot glue to the bottom of that tiny board and secure it to the base of the structure. If you wrap it with tape, it may cause unwanted heating.
John, to secure something with hot glue in an environment with heat cycling is to not secure it at all. The glue is likely to eventually give up and come loose. That power supply board is likely an auxiliary power supply for the control logic. depending on how much heat it generates I would probably just put it in a suitable size heat shrink tube to prevent it from immediately shorting to anything else. Overall, it's a piece of shit design indeed. The triac's heat sinking relies on passive pressure against the sil pad. If it shakes out of place, game over, it will likely eventually overheat and die.
I like how they didn't even use a proper connector on the connections on the right side.. Did they just stuff the pins in there? I wonder if it had been 'repaired' before,and that little supply was bashed in there as a fix.
Nicely done, Dr.NBL. The reason there are two PSUs is probably the controller board was designed first (for driving smaller motors) and redesigning for the bigger motor with a 2nd (or beefier) onboard PSU, with isolation and all that, was more expensive than bodging an external secondary PSU. At first I was thinking that the appliance did not look half bad with all the opto-isolators, heat-shrink tubing and liquid-runoff on the die-cast housing.. until.. that bodged PCB abusing the casing (with insufficient insulation) for heatsinking :( and the flying suppressors (bodged brown cubes) near the motor-drive. (The white pads are thermal-conductor-electrical-insulators - hope your triac has one, if needed) A tip for desoldering - just cut the pins from the dead component first and desolder one pin at a time. Then add fresh solder to the plated-through hole and blow hard from one side while the solder is still molten - you'll get a nice clean hole for placing the new component. No wick needed. Beware of splatters on the other side ;)
I am both crying and laughing at the demonstration of electrical engineering skill. I love the highly technical terms you use to describe that machine. I don't know why, but I enjoyed this video more than most of your synthetic chemistry videos (which I rarely understand, but are still entertaining). Congrats on fixing it!
Future soldering tip: flux and desoldering braid are your friends. Flux pen for 5-10 dollars will save all the heartache (you know the chemistry of removing oxides thus allowing the solder to 'wet' the pads better than we ever will)...and desoldering braid to clean up those holes is just a cheap no-brainer. the expensive stuff is way better, but the cheap stuff (plus flux) is still excellent.
I personally love the "solder sucker" tools with the spring-loaded plunger. Braid doesn't clear holes nearly as well. Helps to have extra hands though.
Very nice knowledge of electronics for a chemist! And yes your soldering of BTA225 was amusing :D You should screw the triac to the base of the heater box to ensure it gets cooled. Just make shore you isolate it with some thermal insulator pad and screw mount from the box which is probably grounded.
Decent repair! The fact that the TRIAC was 'underslung' indicates it was a late substitution for a different part with the reverse pinout, which is very common with transistors and cheap production runs. Replacing it with the exact same part might have been a mistake... look for a _better_ part with the right pin order to put it on top of the board if it goes again. They probably saved $0.10 on a critical part, and that's why it broke. Excellent decision, replacing the opto as well. That's exactly what you should do! And no, there should NEVER be a board flapping loose in the box. Even my one-off prototypes get properly screwed down before getting five volts, let alone mains.
Nice, next time you replace though hole parts, it is typically better to cut the bad parts off and de-solder the remaining pins out of the board. This helps protect the tracks from getting yanked off with the part due to the lower heat.
Well done on the repair Nurd dude, you nailed it. It may fail again or it may not and last for years. I suspect from all the thermal cycles, one of the solder joints on that TRIAC cracked and was arcing on the board. That's why the area around one of the pins was burnt. It's probably a common failure mode for these hotplates.
Next time it breaks, send it off to the youtuber AvE. He's an electrical engineer that loves messing around with poorly built electeonics. "It would appear that the pixies got a bit too excited and let the blue smoke monster out. Let's get to replacin' these here jelly bean parts and see if we can't get her choochin' again."
AvE is definitely not an electrical engineer. Seems to be a hobbyist, and not a particularly experienced one at that given the electronics projects he's showed. He just knows enough to know what he's looking at when he takes something apart.
+Output Coupler Exactly..now Big Clive is an actual engineer with decades of experience, he would be delighted to hack something like this and to enhance it as much as possible.
I would say 9/10 on this repair! You're not showing it off to the president so neatness really doesn't count. It works so you accomplished your goal as well. Next time, you may want to try some inexpensive desoldering braid. Despite all this, I was still quietly snickering at my screen haha. Nice work!
mate add a heatsink to that triac! it shouldnt hang like that! also dont worry for your skills -> there are allot of easy projects if you want to get better ;)
Neat! get yourself a flux pen, a solder wick wire roll and a solder suction off ebay, should total unde $10. that should make soldering repair jobs sooo much easier on you.
That you were able to do your research and not be a complete hack, I commend you. Since this is not your particular skill set. The next time you solder, just remember this. The Solder will flow towards the heat. You can see this in your video. (It is going up the pins, instead of towards the board) Try and place the solder iron on the opposite side of board where the tip of your chip leg enters. (Maybe you could not do that do to what was on other side, I don't know) Either way, I enjoy all of your videos because you think before you do, and provide excellent content. Maybe I can find the time and do a reply video on how to solder. Cheers!
Some hints for desoldering and replacing through hole parts... Cut the part out with flush cutters if you have them. Actually leaving as much of the pins in the board makes it easier to remove them. If you don't cut the pins, you have to heat all the pins to get the component out. This is difficult and you usually end up slowing working the part out while putting a lot of stress on the traces and pads. Now that the pins aren't physically connected together by the part, you'll find heating a single pin and removing it a lot easier. Second tip is to get some desoldering braid/wick to remove the solder after the pins are removed. Clearing the holes will make placing the new part in a lot easier and you are less likely to have shorts, bend pins or message up the traces/pads.
Add a little solder or flux directly to the solder joint you're desoldering, it will make things a lot easier. It also helps to lay the iron across multiple pins at once, so they melt simultaneously.
just in case you haven't found it? triacs usually have a snubber across them to protect from transients. If they blow again relatively quickly look there . . an R - C across the two ac terminals. Then replace the opto coupler and triac again with a higher spec model if possible. all the best. Richard.
Nice vid. Something else 4 a change :D. Only comment: next time cut of pins before desoldering. You probably will destroy the component during desoldering/already burned out, and it might reduces the chance of ripping of the copper traces. But over all you did a fine job!
Just wetting the tip isn't good enough. You need to flux the solder joint. If you put the solder on the iron, the flux burns off immediately. You can also just add some flux yourself. I keep a flux pen around for exactly that reason.
I love any/all your videos. It help you with further burnouts is a simple fix. All you need a a small aluminum heat sink, you can find one on an old PC motherboard. If you continue to read about your triac specs, you will see at some point it will need to have a way to thermical way to cool it down. The heatsink will resolve this. Manufacturers will always design things to fail at some point. It the economics of everything. Oh, for the loose power, hot glue works for me or some type of low to moderate adhesive will work. Enjoy.
Don't worry about soldering leads together like that and desoldering them. In many small pitch applications you apply a lot of solder across many pins quickly, and then go back and reflow any interconnections that are not meant to be there. With proper flux usage they just fix themselves when heated up, and is a standard practice.
i would recommend a dedicated TO-220 package heatsink and a thermal pad (like silpat) with silicone thermal compound. it will improve reliability immensely. Not a bad job overall actually. As something that will help in future repairs, i highly recommend getting some rosin flux and braided solder wick. It can make removal of the old solder infinitely easier.
I don't know why, but hearing your bleeped cursing makes me laugh. Glad to see you got it fixed, and you did pretty well improvising for the lack of solder skill.
If you don't have a desoldering iron (the ones with the suction bulb) you can just pick up a roll of solder wick for $2.50, that should help if you ever run into any more soldering projects.
Not a professional, but some 2-bit insight on the design of the circuit. My guess is that there are 2 power supplies because they're optimized for different things. One could be designed for high power, at the cost of voltage stability, and the other vice versa (voltage stability can be quite important for finicky logic circuits like that controller). As for the separate power supply board, I wouldn't be surprised if it was simply cheaper to bodge in a commercially made power supply when your needs are simple or very common, as is the case for a micro-controller power supply.
They use separate power supplies because it's a piece of shit. Glad to be of assistance. Quick desolder hint: If you're not keeping the part, cut the pins as long as possible and desolder each pin one at a time.
I'm an electrical engineer. For the equipment you have you did a pretty good job! Desoldering is a b*tch. A little MG Chemicals rosin flux and some copper braid makes the desoldering much easier. The copper braid just soaks the solder up. A moistened sponge is also good. Just draw the top of your iron over it briefly as you work. It will keep oxides off of the tip, as well as excess solder. So, without wick, the way to handle the case where you bridged the two pins of the triac would be to clean the solder off of your iron first and then the tip will pull a bit of excess solder off. Just repeat as needed.
Just to help you next time, a little spool of something called desolder braid, it's a copperlike mesh impregnated with flux, slurps up soldier like crazy. Otherwise, the frustration with dealing with that stuff is normal. also, there is paste you can get, then heat with a pen or whatnot. And if the copper trace is fried, you can always follow where that trace goes, and replace the trace with thicker gauge wire, enough to compensate for the trace. Might want to do that anyways, since the trace might be damaged, and now pull more current through what's left of the trace than is good for it. Love the science, learn a lot from you, and your repair skills are actually pretty good for dealing with a piece of shit.
Something about this reminds me of a typical AvE video. I think might be your eloquent description of the quality of the electronics contained within your lab equipment.
There are two power supplies because one supplies the microcontroller and possibly the motor with low-voltage power and the other supplies the heating element with mains voltage, run through the transformer and all that.
I would almost bet the triac is for the heating element at full voltage (hence using the optoisolator), transformer is for moderate voltage for the brushless motor with reasonable drive transistors, and the small power supply is for the microcontroller.
+frollard that seems like the most reasonable way to do it. Plus, unless I missed some switching circuitry, that transformer would be way to small for 500+W at 60hz
+NurdRage you want a desolder pump and solder wick. The pump will remove most of the solder if not all of it including any that is left in the holes after the component is removed. solder wick is very useful for desolding SMT components and cleaning pads or bridges in terms of your soldering skill.... just because you are not a professional in the electronics field doesn't mean you cant try to do the job properly you should get yourself a couple of electronics DIY kits to practice on (most are useless but are good to learn on) and also watch a couple of tutorials on youtube and you will be soldiering like a pro in no time. its not a hard skill to learn but very useful to have and it does take some practice.
also the dual power supplies are set up for different tasks the smaller floating one is likely dedicated to the micro controller and logic, the larger one will likely be for the motor/heater drivers due to the higher current. (without better detail its hard to say )
You should see if you can attach a heatsink to your triac, or even just a piece of aluminum. Increasing the thermal capacity and surface area will likely prevent this from happening again. It's probable it failed from either a higher than normal temperature(of the part, maybe due to high ambient temperature) or merely thermal stress fatigue. A heatsink of any kind will help with both. Just make sure you use an appropriate thermal adhesive like arctic alumina.
Amateur electrical engineer here: the extra power supply is because the hotplate stirrer is a piece of s**t. It was cheaper to buy those little dingleberries and solder them in than to buy all the components themselves and build a nice board. Also, you did alright at soldering.
Ripping the optotriac out was actually a good call. If you don't care about the part you can just cut the leads and remove them one by one. This way there is minimal risk of ripping the pads out.
I've found that it's much easier to clip the component off the remove each lead individually if possible. I'm an amateur and have crappy tools so my iron needs all the advantage it can get:)
Get some soldering wick. It's basically just woven copper wire, but it soaks up molten solder like a towel soaks up water. Just put it against solder you want to remove (either the old solder, or an accident like that blob you had) and press the soldering iron against it until the solder melts and is soaked up, leaving you with a nice clean surface to try again. I suspect the copper forms an amalgam with the solder? Anyway, for soldering, you don't want to touch the solder wire directly to the iron, or else it'll blob up and stick to the iron instead of the circuit board. Instead, press the iron against the board contact and the lead coming from the component you're soldering on, then gently touch the solder to the contact and lead next to the iron (but not touching the iron itself). If the contact is hot enough, it'll pretty much suck the solder right up and leave you with a nicely soldered join. If you end up with a blob on the tip of the iron, you can just wipe it against a damp sponge to get it off without having to shut the iron off and wait for it to cool.
+NurdRage, next time you desodering a component you don't care for, cut the leads off and then you can desoder the leads individually. It is much much easier.
That triac should probably be screwed to a heatsink. For instance, a floor lamp dimming circuit I have here, uses a BT137-600E triac. According to their data sheets, both are rated for 150˚C. Mine is screwed to a 2.5 x 1.5" length of what looks like an aluminum U shaped bracket. Do you have space under there to put any sort of heatsink on that triac?
As much as you cant separate water from solvents without epsom salts, you cant wet out solder without flux. Add that to your soddering kit along side a solder pump and you are golden. If you want to be real fancy, use a solder wick to suck up old solder and make those through holes like new. All of those are pretty much the absolute basic when doing quality soddering.
Electrical engineers don't solder. They have the technicians solder up the prototype/repair the equipment while they play around with circuit traces/motor designs in CAD.
is there a thermocouple in there.. or is it a simple thermistor? I would hope for a 400+ dollar piece of equipment, the company didn't cheap out on the thermal monitoring.
For a longer equipment life, bolt a heatsink to the triac. It doesn't have to be a large one, but beware it shorting out to the case (unless the triac is already at ground) or the circuit board.
Electronics engineer here. That second power supply is not screwd anywhere , because its chineese peace of s**t. Because thats a switch mode power supply, i think thats the step down converter from 12 to 5V for microcontroller, lcd and all other stuff. Motors are inductive loads, which can burst voltage spikes at the circuit, why they cant be connected to the same supply as microcontrollers are
Hey nurdrage,I have a question.Some days ago I was gifted a small asbestos piece (as big as 2 hands).my grandfather,the professor who gifted it to me said its a little bit dangerous but I should be able to use it.can you please tell me how dangerous it is please
If solder starts acting really sticky (like when trying to remove the short) apply a little MORE fresh solder. The added resin will make it behave again.
+NurdRage I watch you're videos with amazement since you ARE a whole lot better than me at what you do. However, I now have a whole lot better appreciation how you must feel when rank amateurs start attempting to make dangerous chemical cocktails. BTW, you might consider where the heat dissipated in that triac is going and what temperature it's die is getting to. This may be the reason it failed in the first place and a heat spreader might help as long as you don't cause any shorts. Another suggestion as you are probably going to enjoy another economical repair is to invest in a solder sucker and wick. It will make your efforts much more rewarding.
Likely that this has two power supplies for isolation. The off-board PSU is probably for the high side switches on the motor driver. I would guess that they either could not source a transformer with another tap or found that they needed another power supply after the board was spun. digikey is awesome. I'm surprised you didn't lift any traces. Usually, if you have a board with plated through holes, you don't need to apply solder to both sides. If you use enough flux, the solder will be sucked through the board. (BTW, I am IPC class 1 and space addendum certified)
Yeah that little PSU was some sort of deadline is approaching quick fix, it would not be hard to make the whole thing work from a single power supply. Oh and about plated holes i just had fixed an old HP 6624A lab power supply that had a non conducting via in it.
solder a wire in the sumbitch. That what we have to do for every via on our prototype boards made on the router. It's a pain for complex boards. On another note: your power supply may have been built on my workbench. My father acquired it from HP when they remaindered a number of the equipment benches in their Liberty Lake facility. I have no idea what was built there, but it is a non-zero chance.
Oh nice one. Not sure where it was made but from the date codes on chips it seams to have been made in 1991. I do have an even older HP signal generator made in Germany, its so old the power indicator is a regular light bulb, but it does go to 250MHz.
If I had to guess the triac overheated and burned out because for some reason it is flapping in the wind. If you dont want this to happen again you should probably put some sorta heat sink on the triac. And I bet you would have a lot easier time soldering if you applied some flux to the joints first.
My electrical background is only incidental to my lab work but: Might be a good idea to find a way to stick an actual heat sink to that triac. It isn't too surprising that it would eventually blow given it has very little cooling. Maybe improve the connection with that metal plate it's next to? Also, you might want to check whether the back of the triac is in fact grounded. The metal back probably connects to one of the pins, and I have seen components like that have live backings (albeit in poorly designed systems). Even further conjecture, but perhaps a potential buildup between the triac and that plate caused a spark and a short? That would require extremely poor forethought by the manufacturer, but hey who knows?
![Lp. Сердце Вселенной #60 РОЖДЕНИЕ ЛОЛОЛОШКИ [Финал] • Майнкрафт](http://i.ytimg.com/vi/YoR0pAV9FVQ/mqdefault.jpg)
At last! The "RAGE" part of NURDRAGE!
A lot of complex scientific terminology is used in this video...
I see...
Thanks man. Should be very useful links video.
I go watch it with my lab mate now. 🙂🙂
Like "Piece of sh*t", huh? XD
*Expensive* piece of sh*t, let's get technical here.
@NurdRage: Your repair work may be amateurish, but it's lightyears ahead of the best that 9/10 people who use electronics could do. And hey, if it works, it works!
I'm usually the guy that fixes everything in the lab so this is great to see. Good to know something like this can be fixed instead of breaking the bank.
I have never seen a hot plate stirrer look so clean and nice inside during a repair. The ones I worked on were used for acid digestion, mainly aqua regia, and were brown rust puffs inside. Great to see one repaired without too much trouble.
The only thing electrical engineers are laughing at is the phrase "I bet you real electrical engineers are all laughing at my epic fails."
True - while at the same time beeing scared that this bloody thing failed hot.
How did this device pass the design review phase?
If the heating fails for any reason, it should fail safe, meaning the hot plate should not heat any more.
I don't want to imagine the damage this hot plate can cause, when it over cocks/boils chemicals.
After seeing this, I would add an emergency off to the lab just in case.
That in the chemistry world devices get sold that aren't safe to use is scary.
(Well, until I think about my former job -we had safty engineers with blinkers (those for horses) on. They where unable to find a safety concern unless specifically told...)
It might not be the prettiest repair ever,but it *was* repaired. Not a fail,in my book.
Considering the Triac is switching mains, I would not call that a repair. The solderblob on one of the legs makes the distance between the pins alot smaller than it should be. That's another short waiting to happen, especially in a lab environment where you create vapors of not only water but most likely also other chemicals that create conductive layers on condensation.
Sure, but he's a chemist. Gotta hand it to the guy!
"The good thing about a price of sh*t is that, because it's a piece of sh*t-" LOOL damn this guy is pissed
that hot plate fucks him up....in last video where he made a probe for it he started cursing even more
it's normal...
piece or shit is piece of shit
...i sometimes get really angry too....like if you need to print smth. important and that stupid printer dosen't work...or worse, it's empty....
+mattibboss what was that video you mentioned?
+Voice of Reason "make a thermometer probe for a westlab...."
mattibboss thanks
Considering that hotplate stirrer with temperature control can easily set you back 400-500 bucks, I'd be mad too
Your soldering skills are not that bad, you just dont do much of it .
Your science skills however are top notch :D
really enjoyed the video, it was kinda fun watching you work a little outside your element.
... oh no ... I punned.
Electrical Engineer here: the reason why is that power supply is flapping in the breeze is that it's a piece of sh!t. Cheap products don't have a lot of engineering in them, because engineering (and giving a sh!t about the design in general) costs money. Chinese knockoff vendors don't spend money... in fact they often will start pulling parts until it quits working, and then puts the last part back and calls it good. They only care about lowest price, safety, reliability, and quality be damned.
Edit- the reason they have two supplies in the first place is to ensure that the microcontroller (and any other logic/control circuitry) gets nice clean power... motors tend to make supply rails noisy, and the proper supplies for such are optimized more for power output, not lack of noise.
I know you probably paid a decent chunk of change for that unit, but that build quality just makes my skin crawl.
+Larry Bolan ah interesting! Thanks for explaining. You think it would be a good idea for me to secure the dangling power supply with some electrical tape? I'm wondering if it hitting something conductive was what made it fail to begin with.
Your best bet is to apply hot glue to the bottom of that tiny board and secure it to the base of the structure. If you wrap it with tape, it may cause unwanted heating.
+John Drachenberg ah, gotcha, thanks!
John, to secure something with hot glue in an environment with heat cycling is to not secure it at all. The glue is likely to eventually give up and come loose. That power supply board is likely an auxiliary power supply for the control logic. depending on how much heat it generates I would probably just put it in a suitable size heat shrink tube to prevent it from immediately shorting to anything else.
Overall, it's a piece of shit design indeed. The triac's heat sinking relies on passive pressure against the sil pad. If it shakes out of place, game over, it will likely eventually overheat and die.
I like how they didn't even use a proper connector on the connections on the right side.. Did they just stuff the pins in there? I wonder if it had been 'repaired' before,and that little supply was bashed in there as a fix.
It's just so satisfying taking something that would normally be thrown away and tearing it apart and fixing it with new electrical components.
The fact that you managed to fix the issue as a non-electrical engineer is astonishing nonetheless!
Nicely done, Dr.NBL. The reason there are two PSUs is probably the controller board was designed first (for driving smaller motors) and redesigning for the bigger motor with a 2nd (or beefier) onboard PSU, with isolation and all that, was more expensive than bodging an external secondary PSU. At first I was thinking that the appliance did not look half bad with all the opto-isolators, heat-shrink tubing and liquid-runoff on the die-cast housing.. until.. that bodged PCB abusing the casing (with insufficient insulation) for heatsinking :( and the flying suppressors (bodged brown cubes) near the motor-drive. (The white pads are thermal-conductor-electrical-insulators - hope your triac has one, if needed)
A tip for desoldering - just cut the pins from the dead component first and desolder one pin at a time. Then add fresh solder to the plated-through hole and blow hard from one side while the solder is still molten - you'll get a nice clean hole for placing the new component. No wick needed. Beware of splatters on the other side ;)
I am both crying and laughing at the demonstration of electrical engineering skill.
I love the highly technical terms you use to describe that machine.
I don't know why, but I enjoyed this video more than most of your synthetic chemistry videos (which I rarely understand, but are still entertaining).
Congrats on fixing it!
It's because electronics is fun, y'know
Thank you for showing how not awesome you are at soldering. It makes me feel so much better.
Future soldering tip: flux and desoldering braid are your friends. Flux pen for 5-10 dollars will save all the heartache (you know the chemistry of removing oxides thus allowing the solder to 'wet' the pads better than we ever will)...and desoldering braid to clean up those holes is just a cheap no-brainer. the expensive stuff is way better, but the cheap stuff (plus flux) is still excellent.
+frollard yup! Definitely adding those on my list of things to get. Thanks:)
Gootwick (available on ebay or banggood) is a really good and inexpensive wick.
P.s. Looks like one pin of the triac has a cold solder joint, you may want to touch that one up.
I personally love the "solder sucker" tools with the spring-loaded plunger. Braid doesn't clear holes nearly as well. Helps to have extra hands though.
Jeremy Lee good braid performs better than a plunger tool any day of the week. It does need to be good wick though.
By the third bleep, this officially became my favorite video you have done, or probably ever will. I [beep]ing love it!
I do this for a living. props for the successful fix
Very nice knowledge of electronics for a chemist!
And yes your soldering of BTA225 was amusing :D
You should screw the triac to the base of the heater box to ensure it gets cooled. Just make shore you isolate it with some thermal insulator pad and screw mount from the box which is probably grounded.
Decent repair! The fact that the TRIAC was 'underslung' indicates it was a late substitution for a different part with the reverse pinout, which is very common with transistors and cheap production runs. Replacing it with the exact same part might have been a mistake... look for a _better_ part with the right pin order to put it on top of the board if it goes again. They probably saved $0.10 on a critical part, and that's why it broke. Excellent decision, replacing the opto as well. That's exactly what you should do!
And no, there should NEVER be a board flapping loose in the box. Even my one-off prototypes get properly screwed down before getting five volts, let alone mains.
Always interesting to see an expert in a field doing something off expertise
Nice, next time you replace though hole parts, it is typically better to cut the bad parts off and de-solder the remaining pins out of the board. This helps protect the tracks from getting yanked off with the part due to the lower heat.
Well done on the repair Nurd dude, you nailed it. It may fail again or it may not and last for years.
I suspect from all the thermal cycles, one of the solder joints on that TRIAC cracked and was arcing on the board. That's why the area around one of the pins was burnt. It's probably a common failure mode for these hotplates.
Next time it breaks, send it off to the youtuber AvE. He's an electrical engineer that loves messing around with poorly built electeonics.
"It would appear that the pixies got a bit too excited and let the blue smoke monster out. Let's get to replacin' these here jelly bean parts and see if we can't get her choochin' again."
Holy shit he actually commented on this video.
Or send it to the hydraulic press channel!
AvE is definitely not an electrical engineer. Seems to be a hobbyist, and not a particularly experienced one at that given the electronics projects he's showed. He just knows enough to know what he's looking at when he takes something apart.
+Output Coupler Exactly..now Big Clive is an actual engineer with decades of experience, he would be delighted to hack something like this and to enhance it as much as possible.
Yes! Send it to Big Clive!
I would say 9/10 on this repair! You're not showing it off to the president so neatness really doesn't count. It works so you accomplished your goal as well. Next time, you may want to try some inexpensive desoldering braid. Despite all this, I was still quietly snickering at my screen haha. Nice work!
Hey man well done, it is not as easy as people think to do this sort of thing.
mate add a heatsink to that triac! it shouldnt hang like that! also dont worry for your skills -> there are allot of easy projects if you want to get better ;)
Neat!
get yourself a flux pen, a solder wick wire roll and a solder suction off ebay, should total unde $10. that should make soldering repair jobs sooo much easier on you.
I’m broke. Please some of you who are better off send him some money so he can buy a new one. These videos are the best.
Hearing nurdrage swear is like hearing my teacher swear. Fucking funny as hell.
How has no one commented that they like your channel?I guess I am first.
That you were able to do your research and not be a complete hack, I commend you. Since this is not your particular skill set. The next time you solder, just remember this. The Solder will flow towards the heat. You can see this in your video. (It is going up the pins, instead of towards the board) Try and place the solder iron on the opposite side of board where the tip of your chip leg enters. (Maybe you could not do that do to what was on other side, I don't know) Either way, I enjoy all of your videos because you think before you do, and provide excellent content. Maybe I can find the time and do a reply video on how to solder. Cheers!
Some hints for desoldering and replacing through hole parts... Cut the part out with flush cutters if you have them. Actually leaving as much of the pins in the board makes it easier to remove them. If you don't cut the pins, you have to heat all the pins to get the component out. This is difficult and you usually end up slowing working the part out while putting a lot of stress on the traces and pads.
Now that the pins aren't physically connected together by the part, you'll find heating a single pin and removing it a lot easier.
Second tip is to get some desoldering braid/wick to remove the solder after the pins are removed. Clearing the holes will make placing the new part in a lot easier and you are less likely to have shorts, bend pins or message up the traces/pads.
Add a little solder or flux directly to the solder joint you're desoldering, it will make things a lot easier. It also helps to lay the iron across multiple pins at once, so they melt simultaneously.
just in case you haven't found it?
triacs usually have a snubber across them to protect from transients. If they blow again relatively quickly look there . . an R - C across the two ac terminals. Then replace the opto coupler and triac again with a higher spec model if possible. all the best.
Richard.
much love to this channel.. we should support on patreons!
Nice vid. Something else 4 a change :D. Only comment: next time cut of pins before desoldering. You probably will destroy the component during desoldering/already burned out, and it might reduces the chance of ripping of the copper traces. But over all you did a fine job!
Don't: add solder to the tip and then try to solder the part.
Do: Put the tip on the part first, and then add solder to the part.
Just wet the tip with a tiny drop of solder for better heat transfer
Just wetting the tip isn't good enough. You need to flux the solder joint. If you put the solder on the iron, the flux burns off immediately.
You can also just add some flux yourself. I keep a flux pen around for exactly that reason.
+Output Coupler Flux pen? What's that? I just use a can of rosin, and I dump the tip of the welder each time I need more flux.
Pretty much all electronics solder have rosin core, so adding extra is not necessary.
+Forssa1 It is necessary, except when you are welding two fresh parts together. Even freshly unisolated wire requires some flux for best results.
I love any/all your videos. It help you with further burnouts is a simple fix. All you need a a small aluminum heat sink, you can find one on an old PC motherboard. If you continue to read about your triac specs, you will see at some point it will need to have a way to thermical way to cool it down. The heatsink will resolve this. Manufacturers will always design things to fail at some point. It the economics of everything. Oh, for the loose power, hot glue works for me or some type of low to moderate adhesive will work. Enjoy.
Don't worry about soldering leads together like that and desoldering them. In many small pitch applications you apply a lot of solder across many pins quickly, and then go back and reflow any interconnections that are not meant to be there. With proper flux usage they just fix themselves when heated up, and is a standard practice.
I love when he curses, makes me laugh every. Single. Time. No fail.
No judgment here!(computer engineering student) multi discipline skills are needed and it's rare to find someone with them.
i would recommend a dedicated TO-220 package heatsink and a thermal pad (like silpat) with silicone thermal compound. it will improve reliability immensely. Not a bad job overall actually. As something that will help in future repairs, i highly recommend getting some rosin flux and braided solder wick. It can make removal of the old solder infinitely easier.
I don't know why, but hearing your bleeped cursing makes me laugh. Glad to see you got it fixed, and you did pretty well improvising for the lack of solder skill.
If you don't have a desoldering iron (the ones with the suction bulb) you can just pick up a roll of solder wick for $2.50, that should help if you ever run into any more soldering projects.
Well deserved KUDOs . Thanks great stuff. Tx Carl
Not a professional, but some 2-bit insight on the design of the circuit. My guess is that there are 2 power supplies because they're optimized for different things. One could be designed for high power, at the cost of voltage stability, and the other vice versa (voltage stability can be quite important for finicky logic circuits like that controller). As for the separate power supply board, I wouldn't be surprised if it was simply cheaper to bodge in a commercially made power supply when your needs are simple or very common, as is the case for a micro-controller power supply.
yea, nothing to say bad, it is what it is, you did fix it, good job on that!!
Loving that soldering
I just love these 'backstage' videos :D
They use separate power supplies because it's a piece of shit.
Glad to be of assistance.
Quick desolder hint:
If you're not keeping the part, cut the pins as long as possible and desolder each pin one at a time.
Wow, well done managing to fix that o_O
I'm an electrical engineer. For the equipment you have you did a pretty good job! Desoldering is a b*tch.
A little MG Chemicals rosin flux and some copper braid makes the desoldering much easier. The copper braid just soaks the solder up.
A moistened sponge is also good. Just draw the top of your iron over it briefly as you work. It will keep oxides off of the tip, as well as excess solder. So, without wick, the way to handle the case where you bridged the two pins of the triac would be to clean the solder off of your iron first and then the tip will pull a bit of excess solder off. Just repeat as needed.
Just to help you next time, a little spool of something called desolder braid, it's a copperlike mesh impregnated with flux, slurps up soldier like crazy. Otherwise, the frustration with dealing with that stuff is normal.
also, there is paste you can get, then heat with a pen or whatnot. And if the copper trace is fried, you can always follow where that trace goes, and replace the trace with thicker gauge wire, enough to compensate for the trace. Might want to do that anyways, since the trace might be damaged, and now pull more current through what's left of the trace than is good for it.
Love the science, learn a lot from you, and your repair skills are actually pretty good for dealing with a piece of shit.
+Magestorm Allgoode thanks for the advice! I'll have a look at reinforcing the trace with some wire. I hadn't thought of that.
id try to heat sink that triac though, just a cheap finned thing with good ol heatsink glue
Haha finally you repaired it.
it's good video I can use it if our lab hot plate got problems
thanks. 🙂
Your videos always amaze me
Something about this reminds me of a typical AvE video. I think might be your eloquent description of the quality of the electronics contained within your lab equipment.
There are two power supplies because one supplies the microcontroller and possibly the motor with low-voltage power and the other supplies the heating element with mains voltage, run through the transformer and all that.
If going down that road, why not just supply the element with 120V and skip the transformer entirely?
because isolation
I would almost bet the triac is for the heating element at full voltage (hence using the optoisolator), transformer is for moderate voltage for the brushless motor with reasonable drive transistors, and the small power supply is for the microcontroller.
+frollard Yeah, I think you got it right. I totally overlooked the part where he pointed out the rectifier that seems to be fed by that transformer.
+frollard that seems like the most reasonable way to do it. Plus, unless I missed some switching circuitry, that transformer would be way to small for 500+W at 60hz
+NurdRage you want a desolder pump and solder wick. The pump will remove most of the solder if not all of it including any that is left in the holes after the component is removed. solder wick is very useful for desolding SMT components and cleaning pads or bridges
in terms of your soldering skill.... just because you are not a professional in the electronics field doesn't mean you cant try to do the job properly you should get yourself a couple of electronics DIY kits to practice on (most are useless but are good to learn on) and also watch a couple of tutorials on youtube and you will be soldiering like a pro in no time. its not a hard skill to learn but very useful to have and it does take some practice.
also the dual power supplies are set up for different tasks the smaller floating one is likely dedicated to the micro controller and logic, the larger one will likely be for the motor/heater drivers due to the higher current. (without better detail its hard to say )
You should see if you can attach a heatsink to your triac, or even just a piece of aluminum. Increasing the thermal capacity and surface area will likely prevent this from happening again. It's probable it failed from either a higher than normal temperature(of the part, maybe due to high ambient temperature) or merely thermal stress fatigue. A heatsink of any kind will help with both. Just make sure you use an appropriate thermal adhesive like arctic alumina.
solder wick works wonders, and when I use to work soldering if a component was broke just break it off pull leads one at time
i guess this thing wasn't skookum enough, good thing that you made it chooch again
Us actual EEs are impressed! Warranty void where prohibited...
Nicely done repair. I'm tired of trash em when broken culture we got nowdays. :(
I need to learn more about soldering. lol
Amateur electrical engineer here: the extra power supply is because the hotplate stirrer is a piece of s**t. It was cheaper to buy those little dingleberries and solder them in than to buy all the components themselves and build a nice board. Also, you did alright at soldering.
Ripping the optotriac out was actually a good call. If you don't care about the part you can just cut the leads and remove them one by one. This way there is minimal risk of ripping the pads out.
I've found that it's much easier to clip the component off the remove each lead individually if possible. I'm an amateur and have crappy tools so my iron needs all the advantage it can get:)
Get some soldering wick. It's basically just woven copper wire, but it soaks up molten solder like a towel soaks up water. Just put it against solder you want to remove (either the old solder, or an accident like that blob you had) and press the soldering iron against it until the solder melts and is soaked up, leaving you with a nice clean surface to try again. I suspect the copper forms an amalgam with the solder?
Anyway, for soldering, you don't want to touch the solder wire directly to the iron, or else it'll blob up and stick to the iron instead of the circuit board. Instead, press the iron against the board contact and the lead coming from the component you're soldering on, then gently touch the solder to the contact and lead next to the iron (but not touching the iron itself). If the contact is hot enough, it'll pretty much suck the solder right up and leave you with a nicely soldered join. If you end up with a blob on the tip of the iron, you can just wipe it against a damp sponge to get it off without having to shut the iron off and wait for it to cool.
+NurdRage, next time you desodering a component you don't care for, cut the leads off and then you can desoder the leads individually. It is much much easier.
Oh man, every circuit I've soldered just winced in unimaginable agony at that soldering job D:
lel. same
saving this one for later. good watch.
That triac should probably be screwed to a heatsink. For instance, a floor lamp dimming circuit I have here, uses a BT137-600E triac. According to their data sheets, both are rated for 150˚C. Mine is screwed to a 2.5 x 1.5" length of what looks like an aluminum U shaped bracket.
Do you have space under there to put any sort of heatsink on that triac?
I dont know why. But I cant stop laughing, the way you say piece of sh*t. It's just, it's so amusing.
As much as you cant separate water from solvents without epsom salts, you cant wet out solder without flux. Add that to your soddering kit along side a solder pump and you are golden. If you want to be real fancy, use a solder wick to suck up old solder and make those through holes like new. All of those are pretty much the absolute basic when doing quality soddering.
soldering flux makes on finely stranded copper wire will wick the solder on to the copper. it makes desoldering things VERY EASY.
If the component is ruined, it is usually easier to cut the legs off in situ, that way you only have to de-solder one pin at a time.
How about a video on the chemistry behind oxides and flux?
Electrical engineers don't solder. They have the technicians solder up the prototype/repair the equipment while they play around with circuit traces/motor designs in CAD.
is there a thermocouple in there.. or is it a simple thermistor?
I would hope for a 400+ dollar piece of equipment, the company didn't cheap out on the thermal monitoring.
this was kinda interesting and refreshing to watch :3
Do you know where can i buy sapre resistence for this eqipment ?
For a longer equipment life, bolt a heatsink to the triac. It doesn't have to be a large one, but beware it shorting out to the case (unless the triac is already at ground) or the circuit board.
Electronics engineer here. That second power supply is not screwd anywhere , because its chineese peace of s**t. Because thats a switch mode power supply, i think thats the step down converter from 12 to 5V for microcontroller, lcd and all other stuff. Motors are inductive loads, which can burst voltage spikes at the circuit, why they cant be connected to the same supply as microcontrollers are
Great job bro 👏
as an electrical engineer i would recommend you to buy a cooling block for the triac
What about upgrading them, I have a 250W Hot Plate that doesn’t get that hot & wonder what would need to be done to make it a 300W.
any suggestion on a hotplate stirrers that isn't a POS but won't break the bank?
Hey nurdrage,I have a question.Some days ago I was gifted a small asbestos piece (as big as 2 hands).my grandfather,the professor who gifted it to me said its a little bit dangerous but I should be able to use it.can you please tell me how dangerous it is please
If solder starts acting really sticky (like when trying to remove the short) apply a little MORE fresh solder. The added resin will make it behave again.
+NurdRage I watch you're videos with amazement since you ARE a whole lot better than me at what you do. However, I now have a whole lot better appreciation how you must feel when rank amateurs start attempting to make dangerous chemical cocktails.
BTW, you might consider where the heat dissipated in that triac is going and what temperature it's die is getting to. This may be the reason it failed in the first place and a heat spreader might help as long as you don't cause any shorts.
Another suggestion as you are probably going to enjoy another economical repair is to invest in a solder sucker and wick. It will make your efforts much more rewarding.
This is why right to repair is important
The magic smoke came out!!!
Made my day again. #Rage-on NurdRage!!!
lol you sound so cheesed at the beginning!😂
Likely that this has two power supplies for isolation. The off-board PSU is probably for the high side switches on the motor driver. I would guess that they either could not source a transformer with another tap or found that they needed another power supply after the board was spun.
digikey is awesome.
I'm surprised you didn't lift any traces.
Usually, if you have a board with plated through holes, you don't need to apply solder to both sides. If you use enough flux, the solder will be sucked through the board. (BTW, I am IPC class 1 and space addendum certified)
Yeah that little PSU was some sort of deadline is approaching quick fix, it would not be hard to make the whole thing work from a single power supply.
Oh and about plated holes i just had fixed an old HP 6624A lab power supply that had a non conducting via in it.
solder a wire in the sumbitch. That what we have to do for every via on our prototype boards made on the router. It's a pain for complex boards.
On another note: your power supply may have been built on my workbench. My father acquired it from HP when they remaindered a number of the equipment benches in their Liberty Lake facility. I have no idea what was built there, but it is a non-zero chance.
Oh nice one. Not sure where it was made but from the date codes on chips it seams to have been made in 1991. I do have an even older HP signal generator made in Germany, its so old the power indicator is a regular light bulb, but it does go to 250MHz.
A little radiator on the triac might be smart , especially for a heavy user ..... Cheers
If I had to guess the triac overheated and burned out because for some reason it is flapping in the wind. If you dont want this to happen again you should probably put some sorta heat sink on the triac. And I bet you would have a lot easier time soldering if you applied some flux to the joints first.
My electrical background is only incidental to my lab work but: Might be a good idea to find a way to stick an actual heat sink to that triac. It isn't too surprising that it would eventually blow given it has very little cooling. Maybe improve the connection with that metal plate it's next to? Also, you might want to check whether the back of the triac is in fact grounded. The metal back probably connects to one of the pins, and I have seen components like that have live backings (albeit in poorly designed systems). Even further conjecture, but perhaps a potential buildup between the triac and that plate caused a spark and a short? That would require extremely poor forethought by the manufacturer, but hey who knows?
i love this guy!!
for an amateur that is decent soldering skills.
thank you for this video, its gonna save me [us] alot of money
can you help me , what is the main problem if the stiirer is turning on but not heating ang hea indicator not lightning?
Hi,what Is the value ( In ohms)from that resistor hotplate ? .In my case ,Tha resistor not heating