Відео

The PCB may be "wicking" the heat away too fast. If I try and solder on the metal microscope base the same happens and the metal base wicks away the heat too fast. If it's just an awkward component or two I'd just fix em up with the iron. Other than that, make sure and preheat the board for a few minutes first. The whole circuit board should be too hot to touch before you start.

@@1over137 hi, this is very helpful, thank you! I didn't know I had to preheat the boardI just start cold. Unfortunately it's 5 tiny tiny parts in a really awkward location and I don't have the skills for doing it with iron. I'll try again today, I hope it works.

@@RootiferasRetroGameplay When designing a PCB there are things to pay note to. Copper transfers heat really well. So tracks do. When you have a large area of copper like a ground plane, the mass of copper can make it hard to flow as it wicks the heat away. Most PCB tools have a feature called "Thermal reliefs" which place a sparse area around the pad with 2 or 3 smaller tracks connecting it to the plain. This is to help soldering on ground plains. If you deliberately put "thermal vias" to transfer heat away from ICs in normal use, these will need special care when soldering as they have a high copper mass.

@@1over137 this is all new to me, I didn't know that. Thank you! I'm trying to repair an old VGA card, it has 6 broken smd resistors. my test solder pcb is significantly smaller than the vga card and it's just a "solder practice" pcb, I think it doesn't have any thermal relief or anything so the solder just melts. I'll give it another try today. Thanks for your help!

It's not easy to see, but it was covered in flux. There is a small puddle of it under the board when it's lifted too. I use a flux pen, it's like a marker. You "paint" the area in flux. I agree though. I probably should have used more. The chip did "spring" itself into place eventually. I never did test the board though.

@@1over137 ah okay youre flux pen guy. never used one of these and can't really say anything about them.

about 330c

Possibly. We'll never know. The "experiment" around seeing if I could cox a bridge out with just the hot air, failed, would have been the death nail. In general, if you bring them up to the solder flow temp carefully, you can hold them there for 30 seconds to 2 minutes. They are far more susecptible to shock heating in localised areas, such as induced by drag soldering directly on the pins at 330*C. Think about it. 330*C iron directly on the end of the IC pin. That's going to induce temps far, far, higher than 220*C inside the chip. If the chip is heated unevenly as a result it can literally crack the leads or the die.

I mean this video is quite old now. When it comes to putting real components on real PCBs, I tend to do a hybrid of the above approach and then hand soldering and drag soldering some of the ICs even just to fix them up. I preheat everything with the hot air so it's too hot to touch at least, so that nothing is suddenly shocked being stroked with a 330*C iron. At the same time, plastering solder paste around IC pins actually turns out to be a bit of a pain, often results in 1 or two bridges. So I tend to put far, far less on ICs, then go back and fix them up with the iron. None of this would be required if you use a toaster oven or a proper reflow, but ... hobbies are the only priorities eh?

Mechanic. AliExpress.

Mechanic. AliExpress

@@1over137 thanks, how about the cleaning liquid? Does the solder paste need refrigeration?

@@douglasflores1462 flux is CW (Circuit Works) No Clean flux pen. CW8100

@@douglasflores1462 Yes on refridgeration. At room temp it's shelf life is about 1 month. In a fridge at 5*C it should keep for a year. You have to warm it up before you use it or it's really hard to work with. A cup of water with 30*C water for an hour should work.

No it was a learning activity. I went on to use the technique to solder whole boards will 100s of components.

Not an expert, however I believe it's not recommended. 18650s have pretty low temperature tolerances. Heating the end up hot enough to flow solder onto, even with an iron, let along hot air, would put the core of the cell well outside it's temperature limits. Doing so with a fully charged cell could have catastrophic results. To summarise. Not recommended, seek professional advice.

I'm told it's normal, it's the high pressure fuel pump and injectors. It's normally like that under the bonnet, if it gets louder you can normall have the pump replaced under warranty, but mine is fine.

@@1over137 cheers for the reply I’ve been having a similar issue ( 2017 model ) it sounds like valve springs or tappets. Very off putting to begin with. I noticed also it doesn’t start ticking straight away with my machine it only starts after maybe 3 minutes of running.

No. Best I can come up with is inductive resonance with the chip's RF can. That or something on the board moving with inductance. It's the same noise you hear on headphones if your PC doesn't have a well sheilded audio section on the board.

I don't think so. Most people don't believe me, but "I" can hear this with my own ears. It's not EM pick up on the mic.

@@1over137 same thing happens for me with my esp32 cam It's defn annoying for sure haha

I think you will be fine. Just be aware that other components around the m.2 socket may also melt and reflow. For the socket it's self alignment will be 100% key. If you have just enough solder and you can get it to flow at the same time across all pins it should self align. Even slightly too much solder and it could bridge. You'll need a scope to see it. I would direct you towards some of Louis Rossmans' repair videos for a more qualified source on finer details of SMD rework.

@@1over137 yes, I was planning to use some kapton tape as shields and will check with a meter.

@@themadatheist1976 Checking the pins with a meter will require the pinout of the socket. For example many of the pins will be "ground", so with a meter they will appear shorted, but that's normal.