EEVblog
Вставка
- Опубліковано 22 січ 2019
- David2's Yihau/WEP 898D+ SMD rework station literally melted down!
Autopsy time.
Forum: www.eevblog.com/forum/blog/eev...
Bitcoin Donations: 38y7DE8HEHNj8fGDtUr4PkCn9nWxiorvvy
Litecoin: ML7oQokTwB38bgzzjLDbRV97HKAHuwRfHA
Ethereum: 0x11AceA38DCA9DbFfB4F35f3F746af65F9dED28ce
EEVblog Main Web Site: www.eevblog.com
The 2nd EEVblog Channel: / eevblog2
Support the EEVblog through Patreon!
/ eevblog
AliExpress Affiliate: s.click.aliexpress.com/e/c2LRpe8g
Buy anything through that link and Dave gets a commission at no cost to you.
Stuff I recommend:
kit.com/EEVblog/
Donate With Bitcoin & Other Crypto Currencies!
www.eevblog.com/crypto-currency/
T-Shirts: teespring.com/stores/eevblog
Likecoin - Coins for Likes: likecoin.pro/@eevblog/dil9/hcq3 - Наука та технологія
For those asking, I checked the TRIAC. It hasn't failed short, but it doesn't detect as a TRIAC with the Mtester (possible not enough current for that). Quick follow-up video coming shortly.
Ok after seeing this, you make me wanna remake my hot air stations control board...... off brand Atten,i think, 858D...
Could be latchup, might not have zero crossed to shut off, could be a cosmic ray hit it at just the wrong moment....
is there a blocking cap across it?
I've had a diferent chinese model at work fail where the comparator in regulation circuit failed and it constantly drove the heating element.
This would have been my guess. Triac/mosfet failure.
Probably taking over the Weller mentality: everything is a fuse if you use it wrong enough.
Every ship can be a minesweeper...
...Once.
“Everything is a fuse if you use it wrong enough!” Needs to on a teeshirt!
This is why every bench needs an "Explosion Containment Pie Dish" for just such an emergency! :)
Big Clive
Ah, true. Just like Clive has one for "lithium and chemical explosions", would be nice to see dave use a few.
Jeffrey [Equine Sanctuary] Unfortunately this would have been way too hot for the explosion containment pie dish, it was melting the metal while receiving fresh power until unplugged.
Yep Big Clive convinced me too! I have the "Pie Explosion Dish" on my bench just for such occasions... :D
@@BrucesWorldofStuff They're very useful for little lithium incidents, like stabbing the lithium cell with your spudger.
The reed switch doesn't control the fan, the temperature feedback loop does. It keeps running for a minute or so after the handle is put on the rest. If the fan stopped as soon as the handle was put down, then it was certainly a fan failure.
You are particularly right. The reed switch is feedback to the controller to know to shut down the heater and fan once cooled.
@@wolvenar I believe when he put it down the reed wasn't triggered and fan happened to die. Now what caused the overheating was without the fan blowing the thermistor wouldn't get a proper reading now. It might have actually detected cooler temps from not having air passed through the length of element and raised temp to compensate.
This was my thinking as well. I don't believe it actuated the reed switch when he put it down, and the fan failed at that exact moment - the fan should have kept on going as long as the heater was over 100C. That should have been his first clue.
I've had my fan start up again if there's any residual heat (I have a Yihua 878).
Dave is right, it should have still tried to regulated the temperature, however with no airflow happening all bets are off.
@@JJayzX Pretty much spot on I would guess as well. Though at some point the thermistor should have gotten warm enough. Probably to warm to be safe though.
Not neccesarily, if the heater is designed to operate safely only at a fraction of the applied voltage, thus relying on a pwm scheme of sorts to keep the average power down, then a triac or controller failure could easily overpower the fan's cooling ability.
If the thermocouple is the only sensor in the handle, then without airflow, you obviously can't detect the runaway fast enough, as you will be relying upon convection only. So the plastic (in the base) will melt long before convection gets the thermocouple (at the exit) up to the set point of, say 400 degress C. Other strategy(ies) will be required.
It's covered in metal and mica insulation so I don't think radiant heat would be too bad.
Richard Rudek I think it'd get VERY hot sitting next to all of those heaters, hot enough to trigger a cutoff if the cutoff circuitry were functional
Nup. This guys on the money. You ever put your hand over the back of a hair dryer? No heat out the end and glowing element wires in about 3 seconds
it would be interesting to test the actual output of the sensor whith the fan off.
not sure how duable in the states this station currently is
well third wire (speed feedback) on fan would prevent overheating due to insufficient air flow (stuck fan) but wouldn't if blades were broken and motor idly rotating.
Not vibration isolation but seal to force all air forward.
Yep, does that too.
@@EEVblog Pretty sure that's its primary if not only intended function.
Sure, gotta make sure the air flow out and not backwards.
Yeah, I have one of these (similar), and the thermal sensor is in the path of the airflow (where you'd want it to be). You only care what the temperature of the air is during operation, not the coil (until it goes meltdown). Likely, a thermal fuse on the coil would be what you want. I could tell because if I set the airflow to near zero, the coil would just turn on all the time and get quite toasty in a hurry.
Dave, pay David so he can buy a decent rework station! ;)
Aye, Wouter. This. A thousand times, this.
David needs to pay David more 😂
A nice Quick 861D :)
@@EscapeMCP Type it right if you want to spam something. RossmanN. Double N.
Over the years he made more than enough money with that, no he throw out some thousand bucks for a JBC soldering iron plus some thousand bucks for the station and some hundret bucks for some new tips.
Why not a more hands on look into the problem instead of just speculation? You didn't even show a multimeter in this video. New lab not setup enough yet to hook up to the heating element, re-solder the fan and power it up and check things and actually determine where the failure was? Or just not worth your time?
He should check the wires from hand piece to the station for continuity, especially the wires for the thermocouple.
Dave is not going to do more than that to check a lowly Yehaaa, Yahoo, or any other brand that costs less than $1000!
James Kerns Jr. Consider the effect of such an investigation though, there's more value investigating one of these because far more people have these than have $1000+ stations. As well, the $1000 stations are (usually) good anyway. The cheap ones need more work to figure out which ones are good enough.
@@mckryall Oh I agree with you, I'm just saying you clicked to the wrong channel for that! Dave is the electronics snob of UA-cam. And I'm not making fun of the Yahua either, I have 1 rework/solder station, 2 temp controlled solder pens, 1 DC lab power supply and a "Big Clive" 'lil USB power supply with Big Clive Mod! I also have 2 older Wellers when they were really good, and I wont spend anymore the money for the Weller tips. I'm sorry they are not noticeably better to me, I think I'd rather use the Yihua, so you will not hear me bashing them. It's also not like that thing should be left unattended anyway, even though that doesn't give an excuse for poor electrical safety, which does bother me.
You are right. Dave doesn't make much use of his equipment in these videos. If he restricted himself to power banks and LED lights the voice would be the only difference to Big Clive.
I never actually measured it, but wouldn't a brushless DC fan always measure open circuit since there's a bunch of transistors between the supply an the stator?
Precisely. A simple test by applying 24V DC to it would have been a definitive test. I have a similar station where the fan driver circuit failed, the fan itself is good and the hot air gun tests fine on an identical unit. I watched this video hoping to find out which component might be the culprit on mine but it was just a waste of time. The commentary really pissed me off, his high pitched squeaky non-stop voice is very irritating and he displays a contemptuous dismissive regard for what he is looking at and doesn't understand.
Wow thats a lot of butt hurt for one soy boi.
Firstly, give there were ONLY 2 wires to the motor... its not going to have transistors in it. Secondly, the price and cheapest option ethos kind of suggest a straight forward dc fan...
And thirdly.. this guy is an expert who would have seen the truth in a reading of ohms that would have suggested another type.
Your comments make you look a fool with little or no real depth of knowlege, and absolutely no respect.
You are a muppet. And youre full of shit. Too full. Its comming out your mouth.
I suspect the triac is the original fault, shorted out so the element didn’t power down when it was put back in the cradle, so the controller tried to shut it off and turned off the control signals for the fan and element, but if the triac shorted the element wouldn’t be able to have its power shut off.
That doesn't explain the failed fan though. Bit of a coincidence to get a TRIAC and fan failure at the same time, unless the fan failure caused the TRIAC failure somehow (I don't see the opposite happening)
There’s several videos online where the TRIAC has failed in these models and caused exactly the same outcome; I think the TRIAC (knockoff part?) failed while using it and didn’t go nuclear until it was put back on the holder.. I’d bet the heater wrecked the fan if anything.
EEVblog - I know you measured the fan but maybe it’s internal control fooled your test, have you tried powering it?
@@EEVblog overhead from the failed control killed the fan?
@@TheDefpom but is the triac actually failed?
The temp sensor would be expecting such high temps as its in the airflow section on the blower, its used for temp select not as a safety device, it was probably regulating the temp as spec but without the airflow the heat just built up in the handle.
GooleyGaz Yeah I think I can agree on that. The plastics are not going to take even 300C so the regulation could be just fine and it would still fuck up everything
While a 6A fuse may have been over-rated for the application, a more appropriate 4A fuse still wouldn't have changed anything about the hot-air wand melting down from fan failure as the element was likely operating normally at the time. The fuse only does any good when something fails in a way that causes excess current draw long enough to blow it.
A bit puzzled about why the temperature regulation didn't reduce the heater's duty cycle after the fan stopped. Did the TRIAC or thermocouple short out? I know my similar-looking cheapo hot-air station is pretty quick at throttling heater power when I change airflow.
"sol dering station" is probably because the other side is "smd rework station" - they just separated both words after 3 and after another 6 characters. With smd rework, it fits fine. With soldering, it fits only after the second break, but hey, if you don't know how to read our characters, if you only know how to read Chinese, it would be just as hard as it is for us trying to write something in Chinese and getting it right.
I think I would check with someone who knows Chinese before I print something that goes into production ;)
No, English obviously has spaces in between words to prevent you from those mistakes. Chinese does not. And second of all, yes you`d think they would check at least for a minute before they put that on there. So that's still a retarded mistake and shows their general company working style which probably is the actual reason why that device failed the way it did.
Ive got the same gun. I always stare at the temp to make sure its cooling down when it put it in the holder.
Use tape to get up the small sparkly bits
My Atten 858D+ v3.0 also does the same thing if I have it in my hand (fan and heating element are working) and then press the middle "store/call" button. The fan stops working and the temperature shoots through the roof, smoke included. Took me couple of seconds to realize what's going on so I quickly changed the temperature which caused the fan to start again. Firmware bug.
I have a 853D 3 "N" 1 and it has done the same thing twice and I figured it out fast and turned down the temp. Also if I have the little end on it [3mm I think] and the fan is turned down all the way it overheats for a few seconds and the temp sensor backs it down. So now if I am going to turn down the fan I also turn down the temp and it evens out as the set point when first started...
I think you got yourself a fake one. I live in China and have a genuine Yihua station.
The fan is supposed to keep spinning when you place it back in the holder, only the heater should stop. Depending on the starting temperature, the fan should keep spinning for a couple of minutes until the sensor measures about 50 degrees C. Also: the plastic shell looks nearly identical but the inside of mine is completely different. The PCB is different and the magnetic sensors (there are multiple in mine) are not simply glued to the housing. The heating element is replaceable as well.
It even has the "traditional assembly display retraction" as in Yihua's "how to spot a fake" guide shown at the start of the video.
Yes, some of the handles have the same plastic for the shell over the hot part like the rest of the handle, but most have a different, heat resisting material.
And even this thing has a fuse WELLER!
i laugh but tbh this isn't even funny, my father and a good old professor on EE told me to get a weller as i am setting up my bench, then thankfully seen Dave's vid and got a hakko, they really made a name for themselves in the past that they do their best to ruin it now
Weller is a big fuse itself...
Weller has its fingers in its ears and yelling lalalalalalala
Oversized fused so it's no better then the weller..
@@kapioskapiopoylos7338 The Hakko FX-888D is a great soldering iron for setting up an electronics workbench. I'd go for that over the Weller!
Thanks for an interesting post mortem!
Just a tiny note from an ex cable manufacturer: Quite unlikely that you would find 8 strand wires. The geometries favor 1 center & 6 around, which equals 7. The next one, used for more flexible wires would be 19 strands, (1+6+12).
The station I have right now is similar to this one, but when the handle is but back into the holder it instead turns the airflow to the max (in addition to turning the heating off), so I guess they have at least attempted to give it a better chance of survival...
On my YiHUA 898 D+, when cradled the blower stays on until the temperature is below 100 and orientation doesn't matter. Features that Davids did not seem to have.
*_Yeehaw 898D_*
Could it be possible there is a malfunction with the Triac? Don't know much about them, but wow, surprising it failed like that. Terrible!
That would be my guess also. Testing the fan should also have been done by applying power to it instead of measuring it's resistance. I don't think that's a valid test if it's brushless for example, or if there's a diode in series with power input
There are several possibilities like that. They are usually pretty robust though.
I put my bet onto it too.
That doesn't explain the failed fan though. Bit of a coincidence to get a TRIAC and fan failure at the same time, unless the fan failure caused the TRIAC failure somehow (I don't see the opposite happening)
My first guess was that the heater control triac went shorted, but if the fan had indeed failed then perhaps it's something else.
If the fan died first, then my theory is that once it failed, there was no airflow to keep the thermocouple 'updated' with the real heater temperature for some time, thus the software did not notice any significant change and did not reduce the duty cycle. Because of this, the heater temperature increased very quickly. By the time the thermocouple tracked the actual temperature of the heater by convection, the temperature value may have been so high (in software) that it was 'out of bounds' to what the program expected, and thus it (the program) did not know what to do or ignored it completely. I wouldn't be surprised if a badly written program with no sanity checking or edge-case testing caused the runaway condition following some hardware failure, but at the same time, I agree with Jimmy Pedersen, a simple resistance check on the fan isn't that conclusive, so maybe it really is just a shorted triac.
I'm glad this video came out. I was given this soldering station (US version) as a gift a year or so ago and once had a similar problem occur. I had the fan on the lowest setting with the most restrictive nozzle on the hot air gun and the temperature skyrocketed to I think 550 degrees C while it was just preheating. Thankfully I caught it before it could get any hotter as I had the unit resting on a wooden table. I currently don't have the money to buy a new soldering station but am wondering if it would be possible to add in a toggle switch in the heat gun to manually toggle the element off when I want it to cool off.
The way the thermal sensor is placed, without air blowing through, how accurate would be the sensor? Circulation and conducting are minimal, so the only major heat transfer would be radiance, right? Could take a while to heat the coupling up enough to trigger a shutdown.
Could it be that the fan motor itself went bad?
I'm surprised this has happened, since I have an identical unit which I've been using for over 10 years, yet haven't had a problem with it. The reed switch is a bit finicky, so care must be taken when putting the heating head back on the cradle.
19:23 this fan is bldc, it have own driver on board. You can't verify it like that!
bldc wouldn't register as open
I have a few of those fans ... They do not show impedance.
I was yelling that at the screen when Dave came back and said it measured open. Surely he could plug it into a bench supply and verify.
Wait, can anything show as an open circuit and still do something when fed 5 V?
@M Rios Say that red wire goes to the gate of a controlling mosfet, or some sort of cmos input.
It seems the triac or whatever is driving the triac failed. That's why the reed switch responded and turned off the fan and the temperature feedback sensor couldn't turn off the element. They should include a physical thermal cutoff switch near the element to prevent this.
I do wonder if there may be something wrong with the position of the thermocouple. Because the way it is mounted it may just look at the temperature of the air around it, and not the temperature of the heating element. So if tried to keep the temperature of the air but if there is no airflow (if the fan breaks or ...), then it would overheat the element and still think that the temperature of the element is ok.
Never leave the area when this tool cools down, keep an eye and an ear on it, a nice trick is to slightly increase the fan speed, and it should cool down more rapidly. Great tool for the price. I also often rotate the tool until i see temperature decreases...
Is the thermal couple working? I have one of these soldering iron dead years ago. That it for 5 years. Now you are making me think to upgrade. What is a reasonable chinese one just with hot air. Have Weller soldering stations and a royal ask a back up.
So as I am considering one of these as a hobby station for occasional use, the build quality of this seems sufficiently good. A fan burning out after 3 or 4 years of substantial use doesn't seem to be a show stopper, especially if one turns the unit off at the switch rather than flapping the red hot thingy around in mid air while wondering wtf to do, haha.
These companies are tested daily by corner repair shops in China. They have to have some quality to survive the market.
Does the thermocouple only detect well when there is air flowing over it - ie the fan is going!
Maybe a MCU brown out without a proper watchdog routine.
I think David nearly had a brown-out when the thing started to meltdown in his hand!
@@Zadster Accurate
Wouldn't suprise me one bit. Hastily compiled chinesium grade lazy slack-ware is in everything. 32K bloatware just for the SPI interface driver..... 5,458 clock cycles to execute 1 instruction. Embedded windows on an ARM chip to blink 1 LED... Use an external A/D converter because the slackware compiler tool couldnt use the internal A/D....
Shouldn't there also be a last-resort one-off thermal fuse to kill power to the element if the handpiece goes above its operating range?
I think they include them on electric kettles and things like that, with something like two springs joined by a blob of temperature-specific alloy.
Is it possible to put some kind of alarm circuit on the fan that would light an LED or trip a piezo so you know?
I had the same one for 8 years or so. A month ago, I picked up the soldering iron, and I could see it was glowing a dull red and I could feel the heat radiating a foot away. Dumpstered it and got the pace one you reviewed. It was quite an upgrade.
My auto shut of is starting to fail I put it on the holder a few times and had to keep playing with before it starting to work again.you can by replacement heat blowers on Ebay ,I may have to do that or replace the whole unit.
18:50.. Since so many of us have one of these WEP rework stations... why not get a functioning one and put it through some possible error conditions to see where it will/may fail ???
Then find a solution to the fail so what happened to David won't burn down our homes.
Just quickly looking at it I can see adding a parallel reed switch to the opposite side of the hand held unit and perhaps a Thermal cutoff switch right at the element supply.
BTW.. my 858D has been working flawlessly for the past 4 years.
I have the Atten branded one. As soon as you put the handle down, the reed switch cuts the power to the heating element and the fan keeps blowing until the elements goes down to 100 C and then stop. So even with a fan failure, overheating of the element cannot be explained as it gets no power when the handle is down. It would just take more time to cool off.
Hi Dave, Sounds like you had fun having a sidekick in the studio. Fun! :)
I wonder how close this model is to the Xtronic 6040? They look near identical. I know i had this exact problem with the air gun on the Xtronic 5040-xr3, but i chalked it up as improper use because it was in a unmonitored student lab at at my university. Where some thought you melted the wires to solder something.
Faults pretty clear to me. The thermocouple is a good 10mm away from the element wire. When the fan blew, there was nothing but convection and conduction to move hot air past thermocouple; it was no longer being forced past. This would make it take a reasonably long time for the thermocouple to register the true temperature of the element, certainly longer than it took for heat to conduct through that thin insulation and the metal can. Looks like they needed a separate thermal cut out in closer proximity to the element to catch an overheating scenario with no airflow
This sounds most likely to me.
It would have stopped heating the element as soon as it got to the temperature. The sensor is not that far away so the effect would have been a slow melt-down instead of a burn-down. At least that's what I can figure from the witness' recollection. I'm betting on a software error as hinted by some other commenter above.
On point, there is still heat but ghe difference to set temperature is huge, definitly high enough go keep on heating, the most perfect solution would be a thermocouple within the heating element and an airflow sensor, but a second TC would be enough, if there is a max temp set for it in the firmware.
Well and truly wellered.
Well said
Heat regulation keeps the output at a set temperature, if the fan fails the output temp stays the same but there is no cooling air to protect the plastic from melting. The heat which is normally carried away finds it way back to the plastic housing. Seems like a second temp sensor would be a good safety feature.
Harman Robotics Even some type of sanity check of the output duty vs sensed temperature- if output is too low, poor airflow is suspected, alarm and turn off output...
Or a thermal switch in the resistor for overheat protection
OR JUST PUT THE DAMN SENSOR NEXT TO THE HOT COIL INSTEAD HAVING IT 25 MILES AWAY. (Black insulation can keep your isolation.)
Might it be that without airflow the thermocouple doesn't get enough heat, since it is so far away from the heating element, causing the regulator to shoot up?
Purchased a year ago. I found it did not always seat properly in cradle to shut down and no cable disconnect for the hot air rework like for the soldering iron. Definitely should never be left unattended, unless completely unplugged!
You two gave me really good laugh, I wish there will be more videos of this kind :)
even if it has an overheating protection in software i think the termocouple was not able to detect temperature because of its position. It seems to be placed inside the ceramic insulation and in contact only with the hot air, so no air no temperature
The exact thing happened to my station (YIHUA 8786d). It's within warranty but they are not honouring the warranty. Will changing the fan solve the issue? .. I desoldered the fan and checked it ... It's not working..... Or is there a problem with the circuitry ?
Often the fan in mine doens't turn on when I remove it from the stand, but the element does.
I could not see in the video checking the fan motor with a 24v supply. So how can you be so sure it failed?
This is a shame, because I was really looking at getting one of these. I absolutely love my TS100 and I have no problem using it as my main iron, it's displaced my need for a soldering station, but I need a hot air rework station, and I figure I might as well get a soldering iron in the mix as well, especially if it uses Hakko tips. Any budget stuff you *would* recommend?
I have the same Yihua board based station. I've seen some stations burned by the triac, that's why I never leave the handle on the holder when the hot air switch is on. When I turn the hot air switch off its cools down also, but the switch is turns off the heater physically, not through the triac, that's why I'm sure my station won't be burned like this.
I was thinking to put some additional relay protection in the station, which can switch the heater off when the fan is stopped, but I don't think I really need this now.
What I do with mine (different unit entirely but still ebay) is once it starts ramping down, I turn off its power switch on the unit. Just in case you know?
I am thinking of rewiring of my 858D. Mains switch should physically cutoff power from the heating element. I know, it means using larger switch. I have 858D for six years and have no problems, but I ran into similar issue with same optocoupler (optotriac) used here, which sometimes (and I do not know why) turns on and stays on despite the fact that diode part of it is unconnected and stays in this weird state until the triac side is disconnected. Then it returns to normal. It's rare, but it happens.
I am using central switch to cutoff everything on my table, so the soldering station is most of the time disconnected from the AC, but it's not good feeling to know that there is only silicon switch (with weird optocoupler) between AC and heating element.
I have this soldering station and had what seems to be the exact same failure. The fan stopped working and the element would keep heating up. Luckily the reed switch still worked so I put it down and turned it off. After replacing the fan, the station is still working and in use about 3 years later... I think it might be time for an upgrade
i have one of the ebay ones it has a temp up to 480 degrees and the fan will stay on until the handset is down to 100 degrees before shouting the fan off so it may have been just to hot with no air flow to cool it down
the fan does not stop when its on the cradle until it reaches 100 degrees so he should have known something was wrong as soon as the fan stopped and the degrees had not counted down
Not appreciating the highly engaging thumbnails.
He gotta do it to draw in people who love click bait. The thumbnail is on the verge of breaking UA-cam's rules as you never see a solder station on fire. If I wasn't subbed I would have never watched this video. I did skip most of it as I knew it was a video about something broken and speculating what went wrong rather than finding out. Can't please us all. Tangobaldy
Anything else you'd like to complain about while you're at it?
@@EEVblog I'm subscribed to this channel for probably more than 5 years now. Thank you for your honest interest in my concise and constructive feedback.
Lab needs more females.
Tough shit.
7:10 because red color means where electrons are flowing from.... duh everyone knows that electrons are blue
My school outfitted their lab with 853D's (which feature the same heatgun, etc. + power "supply")
I've seen a few of them meltdown in a similar manner.
There's a software bug (in the 853Ds we had) : if you keep cycling it between active/holstered in a short amount of time the processor locks up and stays in a random-state {(fast) heating up, steady w/ fan, cooling off, off}.
The workaround was to listen for the fan to shut off on holstering. If immediate then switch the unit off then on again, and don't leave anything heat-sensitive where the holstered heat gun is pointing. (Was actually convenient when shrink wrapping stuff.)
OFC with sixty hot airguns to choose from, this wasn't a serious issue, unlike the input filters starting smoldering fires because of an inappropriate component choice(?) Those all got replaced/retrofitted before being installed so I can only guess what the TI changed.
That would be a good info to put into the 898/853 thread on the eevblog forum. A lot of the people have studied all the variants and started doing mods to make them safer.
I think what happened that the fan stopped working and the sensor detected the temperature increase so it set the heater to the lowest setting but without air flowing it wasn't low enough because it probably wasn't programed to deal with a fan failure.
Isn't thermocouple just too far away from heating element? When no air is flowing, then I guess just part of heat will get to thermocouple.
It would be great if there was some kind of pressure (air flow) sensor like in industrial gas burners - when fan fails, solenoid shuts off gas inlet.
Here's a wild idea: could the reed switch have become partially-magnetized? I've seen it happen with burglar alarm door magnetic reed switches, move a magnet past metal enough times and it picks up a little magnetic charge. Maybe a combination of that and a lack of a firmware failsafe lead to an isolated occurrence?
I sure hope that the white insulation material isn’t asbestos!
I'm curious what that material that is. I took out a thermal fuse out of my hot air gun and that stuff feels like some sort glass fiber
Ed Gein It is! If you google mica heater you get tons of results at alibaba
It's mica. A naturally occuring mineral just like asbestos, but the flakes are quite different in shape compared to asbestos and aren't known as carcinogenic. Since it's so flaky, it isn't usually used as a wrapper. It may have been reinforced.
Looks like mica + glass fiber to me
According to my book it’s a mica wrap. I have a spare heating element. It says do not remove mica wrap to avoid short circuits.
I have a model 855D and mine has the soldering iron heat gun and a variable voltage supply. I bought it new off ebay for $89 and have used it the last 6 months and have had no problems whatsoever. It's possible to get a Lemmon every so often.
I've got one of the similar model (YiHUA 8786D I believe) for my first year in college. Back then it only cost me ¥200(~$30) or so for both a rework and a soldering station, which was quite an affordable price for amateur student hobbiests like me. The station works pretty fine for a year, before I decided to go 'professional' and bought a ¥150(~$22) standalone T12 soldering station. But the rework function of that YiHUA model is still used until now, which helps me get through a great amount of troubles in the past year without any failure, and that magnet is actually very sensitive and reliable.
One thing I've noticed is the temperature sensor on the airgun is not directly mounted to the heating element, which is quite reasonable because it is supposed to measure the heat of the airflow, not the heater. That means it requires the heat to transfer through the air gap before the sensor can sense it, and with the absence of airflow the heater can heat up dramatically before the sensor reach the target temperature. Another thing is that the airgun still blow air to cool down after it is placed back onto the holder, which means it is very easy to spot a fan failure at the scene, and you probably don't want to leave things like this working away from the scene.
Anyway, you get what you pay for, don't expect too high on a cheap model, otherwise the producer won't get enough profit to survive.😉
I have a cheapie, and when I holster it, it turns the heat off but the fan runs until the temp sensor reads below 100C.
How come the fuse is rated so high? Could they be using a 220v transformer on 240v running it into saturation?
Bucket of Sand.
It's old school but a bucket of sand is great for electronics fires like Dave had and it's not as much of a commitment as breaking out the fire extinguisher.
also you can get a model that does not countdown and stays at the set temp or you can modify your unit so it does not switch off when on the cradle which this one may be, as the reed switch should have turned the heater off
I have a similar one and mine doesn't turn off the fan until the temperature of the heating element is at 50C or less. The fan died once, though. Turned it off, swapped the handle and is still working to this day.
do any product connect N and ground? here both is live so that will be catastrophic.
David and Dave, well now you have a transformer for that Weller. WEP and Weller colab. 😂😂😂😂
Wrong voltage (s) out of this one I believe.
But it DOES have a primary fuse. LOL
@@wolvenar IKR 😂
My OKI brand hot air rework station had a plastic part holding the metal heating tube in the handle. It melted and broke so I machined up a new aluminium part which has proved to be the duck's nuts. The part holds the tube below where the heating element is located so when the air is flowing all will be ok. When you turn off the station, the air continues to flow for some time to cool the metal tube. I think mine was stopped a few times before the air timeout and this proved fatal as it lets the hot element heat the tube which melts the plastic parts lower in the handle. I'm going to pull mine apart again and see if I can increase the air timeout. Not really related to the problem above, but something to watch for...
yeah this might be a joke but that leaves the question then, what is weller?
there should be a temperature fuse in the heating element, should be rated for around 500C, so if the fan does fail the element wont get too hot. that is why my X-Tronic unit says to keep the fan speed knob above 5 for temperatures over 400C.
"Input fused. There you go Weller."
Shots fired.
That thermal sensor looks too far away from the actual heater for me. Maybe it wasn't registering anything faulty due to the low thermal conductivity of the ceramic base while the thing was already melting, and the missing airflow was supposed to be moving the heat from the coils onto the sensor, but obviously wasn't there to do that?
What diference does it make if it is soldered instead of crimped i for one Would take soldered over crimped any day the fan wiring is fairly standard style for a tiny 12 volt fan look at any computer or anything thathas small fans like that same wire
I had almost exactly the same thing happen a few months ago. Same WEP brand. It was an air-only model. I set it on the cradle, and a few seconds later I heard a POP and my lights flickered. I looked over, and the whole metal part of the blower was orange hot. I am absolutely sure that the fan was still running. I hit the power switch immediately and unplugged the unit from the wall.
There was no smoke or flame. I took the handle apart and there wasn't any noticeable damage to anything. There was a small spot up on the metal casing that *looked* like the heating element had shorted and created a weld. I took the chance and tried turning it on again in a safe location. The fan ran but the heater did not come on.
"Fortunately" mine was only a couple weeks old and I was able to return it to Amazon for a refund.
Looking in forums afterwards, I read some of the best advice for these: It's good for the price but only use it in the middle of your driveway with a fire extinguisher handy.
Took mine apart...looks like the opto that drives the triac is mechanically stressed due to flex in the pcb due to the isolation slot beneath it. My opto seems to have a microscopic fracture, barely visible to the eye.
SCR went short hence the thermal control was lost. Also the fan has control electronics and cannot be measured as a coil..
The thermal couple was properly located beyond the last coil of the output. But when the fan cut off and the tool was docked, it was at the bottom of the heat coil. As heat rises, the cool air is drawn into the nozzle passing over the thermal couple telling the processor to increase heat. Even if the thermal coupling was working fine, the heater housing would be kept far hotter than designed.
I had something with almodt the same handle but it blows until it cools to 80c before shutting off
I got the same 898D and had it since 2013-ish no problems(cept user error). Mines got MarkEthan branding instead of WEP and no missing space between "sol dering" but not CE listed on the front panel :|
So the fuse needs to be swapped out for a lower value?
Did the user place the hot air gun incorrectly back into its holder? , I wouldn't have know that there was a particular way to place the wand back into its holder.
It may be that the element continued to be regulated at an elevated temperature when the fan failed, the temp. sense is down stream of the air so when the air flow stops it only gets radiated heat which would make the device think the element is cooler than it is.
A thermal fuse inside the housing would have saved it from melting, along with a software change and you're good to go. All David needs is a new hot air gun, a thermal fuse and you'll have it up and running in no time. I think they designed it to be pointing down when in the cradle which isn't very ergonomic, next one, cover the cradle in magnets.
U have question any idea about kkmoon 858d 700w?? I think it's better than this or am wrong
I also have a 898D from another company, and one of the greatest dangers of those devices, is that they will start when removed from the holder, EVEN IF YOU SHUT THEM DOWN FROM THE CONTROL PANEL. And by the way, mine had no information sheet whatsoever to tell ma about this magnetic switch behaviour - which made me thing first that it had spurious restarts until I realised it was when I removed it from the holder...
I think the problem is due to the position of the thermal sensor, it is far from the resistor and when the fan broke, read less temperature than the actual temperature of the resistor!
that happen to mine 2 days after i bought now cant get it to work anymore as hot air station bought an bakko handle that seemsto be a bit better doesnt work checked the wiring and it shows S-E on the hot air screen..heeeellllllpppppp
Weller : Fuses are overrated. Meh.
WEP : Meh. Over-rate the fuse.
Oh my god..... now i understand trump..
Where does it start spewing flames?
I to have had one of those heat gun parts on a two in one stations. And the heating element shorted to the case and blew up.
one problem I noticed is that the temp probe requires airflow for proper sensing. it wouldn't explain this fail because it would have sense the temp before it went completely nuclear but it could be a contributor.
I've got one of these that's so old it doesn't even have branding on it (there's a blank space where a logo would go, and the model code 898D+). I have no idea if it still works since I rarely ever used it. But thanks for the warning, I'll be sure to make sure it doesn't go supernova whenever I use it next.