Kenwood KA-7100 no sound

[Gbtr6]

I have a nice fairly clean KA-7100. Passed DBT, relay clicks but no sound. Tried Aux, Tunes, Tape A also. No go. I’m going to test the output transistors as I have a Luxman R-3045 that had a pair of those shorted out. In the first picture , I assume the round silver items are the output Transistors. In the second picture, I assume the output drivers are Q 31 and Q 32. Any ideas as to what to test and how?

Thanks,
Perry

 

[sregor]

Since you have relay, I seriously doubt that problem is bad output. However, it could be...
Start by eliminating the easy parts. Make sure there are no shorting plugs in the tape outs on the back panel. Make sure the knobs are on correctly. Check the fuses on the amp board. There are two sets of secondaries in the transformer, so fuses on one side could be blown, and the amp still turn on. If there are blown fuses, then could have bad outputs in that channel, or bad rectifier for that channel. Clean the controls and switches, especially the filter switches and tape monitor switches.
Service manual if you need it: https://akdatabase.com/AKview/albums/userpics/10004/Kenwood KA-7100 Service.pdf

 

[p4spooky]

Great suggestions by @sregor

Also check regulated power supplies that powers the preamp section.

 

[Gbtr6]

Thank you both for the replies and the service manual. I’ll have to learn how to test those items. I’m more of a prts replacer and cleaner.

Thanks,
Perry

 

[Gbtr6]

Well, it's been a while, but i cleaned all the switches and controls and it came back. One of the filter switches was the worst, Hi cut or one of those.

Perry