• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

G-3500 Troubleshooting Help Needed

ShaneC

ShaneC

Super Member
I've got a G3500 I picked up at the thrift store. Problem is, I'm getting a constant 32vdc output on the right channel (both A & B).

Now that I have the schematics for it, I'm realizing just how out of practice I am at trying to read them and troubleshoot down to the component level.

The schematics are linked in 2 parts if anyone can help me figure out exactly where to check. I've poked around a bit, but I'm having a very hard time finding the right spots on the board. (Mostly keeping my eyes focused tonight).

Schematic Pt1

Schematic Pt2

I'm just guessing at this point, but I think the problem may be at TR16 and/or an associated component.

Any help is greatly appreciated.

shane
 
Register to hide this ad
Hi ShaneC, start by checking the output transistors TR16,TR18 and TR15,TR17, then check the drivers TR13,TR11 and TR12,TR14 and work your way back and check TR10,TR8 and TR9,TR7 if all these test ok have a look at IC01 and IC02 2SA 798 differental inputs, they are just two transistors in one package, you should be able to check for any thing thats not right with a meter, I have had these fail in the past and they can cause an offset which can put the supply rails at the speaker terminals.
Also check resistors in the output stage, especially any coming off the +/- 32 V rail from the power supply.

Hope this helps
Cheers
Glen
 
You must log in or register to reply here.
Back
Top Bottom