A/C Amplifier pretty corroded......Any chance it can work again ?? (1 Viewer)

[BullElk]

Reckon this is my A/C problem? Any special cleaner and method recommended to at least try to salvage it? Thanks

 

[Parsnip]

Acetone and a small paint brush with its bristles cut to about 1/4" to make them stiff. You will be cleaning off the lacquer then the nasty stuff under it. If it works, spray with new lacquer to protect it. Take a close look at those caps to make sure they aren't leaking. That board looks ok even if you have to replace some of the components.

 

[blkprj80]

No on the acetone!
It will eat the resins in the board and damage plastics.

Use 99% isopropyl alcohol and a cut off acid brush.
You can use soapy water and a toothbrush too. Let it dry well.

 

[BullElk]

Thanks alot. I will try that now.

 

[blkprj80]

Once you get it all cleaned up, you will want to look for circuits that are open due to the corrosion. That ribbon wire looks bad. Make sure the resistors have legs that aren't eaten away, and any other components.

You can probably source all of those components from DigiKey. I can help you identify them.

 

[BullElk]

Here are pics of amplifier after cleaning. I tested a good amplifier from my other LX and everything worked perfect....so I know the ac auto amplifier is the problem.

However, After installing the cleaned one it still isn't working. I am not real familiar with a circuit board but, to me, everything looks good. I don't see any thing loose or broken....but something is still not right.

 

[Tools R Us]

Could just be the pic, but the resister P010 looks like it's not connected, missing a leg? Also clean the connector pins next to it.

 

[blkprj80]

R010 definitely has a problem. He only has one leg, the other is goners.
I'd check for missing metal in the areas I circled.
I'd also replace that 4 pin connector as it is very corroded and probably will have a bad connection over time.

 

[blkprj80]

Oh, and it cleaned up better than I would have expected. How did you do it?

 

[BullElk]

First used soap and water with touthbrush. Then put a little brake parts cleaners on toothbrush and scrubbed. That's when it cleaned up better.

How on the beautiful earth do you replace the parts and pieces you said? Find a jeweler or hobby airplane mechanic?

REAKLY appreciate you pointing out the obvious problem areas. I am smarter today.

 

[blkprj80]

Hopefully someone in your area is on 'mud and knows how to use a soldering iron. If you were closer, it would be fixed in a couple minutes.

You're looking for an electronics technician, possibly an electronics repair place that does old radios and stuff like that.

 

[Tools R Us]

Post a closer/better pic of it, can't make out the value. They are cheap, worth a try to replace?

Beleve it or not, there are a ton on YouTube:

 

[blkprj80]

It looks like a 5.1K 5%, 1/8W to me.
Green Brown Red Gold

 

[BullElk]

Soldering the resistor looks mighty simple. Who sells resistors? Hobby Lobby? Oreillys?

 

[BullElk]

Close up shots...