Yihua 908D soldering iron seems to have given up the ghost.

[KaoDome]

Hi everyone, so today I was about to solder something when I realized my soldering iron acts up. It's out of warranty for a couple of months, but I had only used it for 4-5 times over its life, so I'm kind of bummed that it doesn't work anymore.

When connected to the mains voltage and turned on, the 7 segment display and the heater LED light up for a fraction of a second and then turn off, repeating this cycle indefinitely. It's not able to heat up this way (in a reasonable time anyway), so it's useless as of now.

I decided to open it up, in the hope of finding some component that needed replacement. It doesn't smell like burned electronics, and there's nothing evidently broken in there to me; but I barely know the components that make up the circuit since I'm just beginning with electronics, much less the circuit at this point. Besides, there's a microcontroller in there, an S3F94C4 so it complicates things.

I don't own any other soldering iron to desolder or replace components, but I could get access to one (I do have a multimeter, but no scope either). How would one go about repairing something like this anyway? I am thinking about going through the traces and try to reconstruct the circuit, and then see what's up. Would it even be worth it anyway? I spent around 30 bucks when I got it, which isn't much, but it's significant for me.

I'm attaching a couple of images in case anybody more experienced is able to see something I don't, thanks anyway for the time and the advice on how to procede.

[Armadillo]

Can you take this photo close up again?

[KaoDome]

I couldn't focus it cleanly right now, but that seems to be the problem, that leg of the (smoothing? ripple filtering?) capacitor is lose. I'll solder it properly tomorrow, but I made sure it was touching the board before plugging it in and it works as expected now. Thank you very much!

I'll make sure to clean up the board too, that area has some yellow-brown-ish deposits as if it were corrosion, but I'm thinking it could be some flux residue, it has certainly not been near water while in my possession.

[oventech]

Bad soldering, mistake totally missed by assembler,QA.  Resolder that point. clean the PCB with IPA. Clean both sides of the board. Reassemble and use it. Good luck.

[perieanuo]

Ha ha, needs a solder iron to repair the solder iron


Envoyé de mon iPad en utilisant Tapatalk

[Rasz]

Ha ha, needs a solder iron to repair the solder iron

of course. buy cheap, buy twice

[bd139]

This doesn't surprise me. I remember when I had an equally shitty Aoyue iron. The element went pop. So I tore the iron down and realised I needed a damn soldering iron to replace the element  . So I bought an Antex XS25 and used that to fix the Aoyue. Then I thought "hey this Antex firestick is less shit" and just used that.

Also I recommended one of those T12 irons to someone a couple of weeks back. I said "buy the assembled one". What did he do? Bought the bloody kit so guess who has to assemble that because he doesn't have a soldering iron 

[stj]

 
now that's funny, buying a kit when he didnt have an iron!!

is he an idiot, or just very devious?? i would charge him the difference in cost between the kit & assembled version to build it. 

[bd139]

He’s definitely an idiot. I am just avoiding him now 

[mnementh]

What you do is you tell him to drop off the kit so you can tell him what it needs to be assembled.

THEN you avoid him. 

mnem
Like the plague...

[bd139]

He’s got the kit. Had three SMS messages today inviting me over on Saturday for dinner. The sociopath in me wants to go because the food is always good and just forget the soldering iron 

[mnementh]

Well, speaking as someone who routinely cooks for a family of 2-20 (depending on how many of my two children are home ) , I can say with some degree of conviction that the level of assache involved is probably worth right around 2 good meals, or one VERY good meal. As long as someone else cleans up afterwards. Of course, I've got a fair amount of experience building these now, and it probably wouldn't take me more than half an hour or so... and I'd still let him screw everything together once I'd got it soldered up and working. 

mnem
I am not my pants. No, I am not your pants either.

[stj]

He’s got the kit. Had three SMS messages today inviting me over on Saturday for dinner. The sociopath in me wants to go because the food is always good and just forget the soldering iron 

go over, and leave your irons at home. 

[mnementh]

bd's way ahead of you... 

He’s got the kit. Had three SMS messages today inviting me over on Saturday for dinner. The sociopath in me wants to go because the food is always good and just forget the soldering iron

mnem
*Waiting for the Electrician or Someone Like Him*

[bd139]

I’ve decided to actually help seeing as I’m getting slow cooked ribs 

[GreyWoolfe]

I’ve decided to actually help seeing as I’m getting slow cooked ribs 

I would do it for slow cooked ribs, especially if there is home made potato salad and cole slaw.  And beer.  But after the soldering.

[bd139]

Beer is good for soldering. Helps counteract the shakes from the coffee 

[GreyWoolfe]

I don't really drink coffee so the beer might give me the shakes.

[mnementh]

I’ve decided to actually help seeing as I’m getting slow cooked ribs 

... I can say with some degree of conviction that the level of assache involved is probably worth right around 2 good meals, or one VERY good meal. (SNIP)

mnem
I am not my pants. No, I am not your pants either.

It would appear that your "price" is very similar to my own. 

mnem
*Always willing to prostitute my genius for the right combination of food and friendship*

[bd139]

Indeed it is 

Edit: paid with ribs. Was a worthy meal for the job. I’m happy.