Help TCI repair

[Frankk]

So my yamaha maxim 400 have problem starting when there's a lot of moist but it start well when it's dry. I'm pretty sure it's the TCI because when the bike is not starting I use the hair dryer a few minutes plug back the TCI and the bike starts.
I searched a lot and didn't find any replacement for it and the used ones are 100$ +. So did anybody had any success repairing their TCI?

So I red somewhere that there is solders to remove first in order to remove the TCI from the box. Can some one help me figure out wich one to remove first? I receive my soldering station soon so I'll keep you updated.

Any tips would be appreciated thx!
P.s The thing that looked like rust is red I dont think it's rust

View attachment 35526

 

[amc49]

The brown is likely mostly rosin from the original solder job, it does not normally conduct to short things out.

If you've gotten some moisture in there to rust things, the steel pins the semiconductors mount with WILL rust. Last pic almost looks like a slight layer of water at some times on the bottom.

You may need to waterproof that better.

 

[Frankk]

Alright thx i'll try something like this https://www.amazon.ca/MG-Chemicals-Premium-Acrylic-Conformal/dp/B07B8RY7M6

 

[amc49]

You can do the same with simple epoxy like J&B weld and much cheaper.

 

[Frankk]

I'll try it

 

[Frankk]

Alright so I got the bad boy out and now I think that I will just wash the board with acetone to remove the yellow thing, then dry it and put the epoxy on it! I will also clean the connections. If you can suggest me anything else to higher the chances of success plz let me know. I have some basics in electronics so I'm not sure what to look for maybe you will see some problems that I dont.
Thx!

 

[Frankk]

In fact I will replace the capacitors, resistances an diodes that I can acces it's worth almost nothing so let's do the max I can

 

[amc49]

Have you ever worked with multiple layer PCBs? Doing that may end up being less fun than you think.

And DON'T use acetone, it will likely eat the green part of the board as well as any soft potting compound or fixing glue and likely remove resistor and cap markings too. Use alcohol instead. 90/10 if you can get it in a covid age. I'm having trouble doing so here.

 

[Frankk]

No I have not but I wont remove the "second layer" there's only 2 resistance under it that I could replace so I'll let them be. Alright I'll look for the alcool.

 

[Frankk]

Finally, I had it repaired at a local electronic shop for 100$. The bike works well now, no more ignition problems. They soldered everything back in place so I don't have pictures.