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Subject: RE: Repairing faulty AT sensor

From: <joachim.milson@...>
Date: 2013-12-06

Ouch ! There is glue here and there and especially on carbon tracks! I don't know if that's a recommended thing. But don't remove it for now as the result might be worse. You should try and find how this glue reacts with carbon tracks in time.

I reposted your photo with a few labels to make descriptions easier:
http://groups.yahoo.com/neo/groups/yamahacs80/photos/albums/1557574004/lightbox/1723503384

So you have two damaged AT circuits, I call them 1 and 2.
- The one on the left (1) has a defective R1 that was fixed with a parallel resistor RA.
- For the one on the right (2), it's less easy to analyse because of the glue, but two resistors are used: RB and RC. RB seems connected directly to R4 through a white wire, which suggests that both R3 and R4 are damaged. It's not clear where RC is connected to, nor where the other end of RB. Could you check this?

Which circuit corresponds to the defective key, 1 or 2 ?