Are these burns on the board and how to remove them

Thread Starter

capacapa

Joined Mar 31, 2012
17
These black spots look like burns, aren't they? is it possible to remove them or fix this board ? is it safe to use alcohol to clean this, I also have arctic cleaner, not sure if it is also effective with this kind.

 

#12

Joined Nov 30, 2010
18,223
There's only one way to find out, and it's the same way you would begin to repair the board..scrape the black coating off and see if the copper underneath is damaged.
 

Thread Starter

capacapa

Joined Mar 31, 2012
17
yes like #12 said, in the middle board the one in the middle of the picture, near pins 23, and 12,13 and little at the end.

I'm beginner, so please bear with me.

What's the best tool to use to scrape the black spots without causing damage? is there a suitable cleaner to try before attempting to scrape?
 

#12

Joined Nov 30, 2010
18,223
If a solvent will take it off, it's not burnt. (I don't know of anything that will dissolve carbon.)

I use my pocket knife.
 

Gdrumm

Joined Aug 29, 2008
684
I've used a small brass bristle brush to clean boards, just don't be too aggressive.
Isopropal Alcohol works well too, with an old tooth brush.
(Wear safety glasses).

The bottom left of the board looks like a blown SMD to me, and some of the other debris looks like acid residue. (my opinion).

Nice photo, how did you get it so clear?

Is there a specific problem being caused by the board?
HTH,
GAry
 

strantor

Joined Oct 3, 2010
5,671
They sell fiberglass abrasive pens for this purpose. you can get them at radioshack. I don't like them or use them much, just informing that they exist.
 

#12

Joined Nov 30, 2010
18,223
I dunno...I blew this pic up on my 24" LCD and it looks like paint at that size.
BE CAREFUL with that screwdriver! It doesn't have a sharpened edge!
 

GopherT

Joined Nov 23, 2012
8,012
This looks like a 30year old game console (Yamaha sound chip and "joy stick" on the PCB). What is it? A PacMan or a home console?

EDIT:
My error, that is a Yamaha video display processor and you have an MSX2 computer!
 

Thread Starter

capacapa

Joined Mar 31, 2012
17
Yes, it is MSX 2+ HB-F1XD, the problem is no video out or RF but the computer works fine. The middle one is the encoder board.

I confirm this is paint turned out, I touched it a little bit with screw driver and immediately part of the black spot was removed, then I used arctic grease remover and an ear pick, and I was able to remove all the black spots but tiny bits on some pins which is probably wasn't the problem.

I suspect now the caps above this board. yesterday, I found a service manual for this computer online, so going to test the pins in/out.

Nice photo, how did you get it so clear?
This is using dslr camera, Canon EOS kiss x5. original photo was more clear, 4k in resolution, but I think tinypic resized it down.

Thanks everyone for the help
 
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