Pioneer SX-780 Problems

[Bradley J]

Hi all, I was able to pick up a Pioneer SX-780 for $50 today. It does have some issues. It powers on and all the lights come on. The relay doesn’t click on nor does the FM meter move. All the fuses seem to be intact. Any ideas on what and where to start troubleshooting? Thanks so much!

 

[ivandezande]

Hi all, I was able to pick up a Pioneer SX-780 for $50 today. It does have some issues. It powers on and all the lights come on. The relay doesn’t click on nor does the FM meter move. All the fuses seem to be intact. Any ideas on what and where to start troubleshooting? Thanks so much!

Check voltages on the STK packs, and in the power supply. Somethings dead, and I bet it's the packs.

Also might want to change the thread title.

 

[Watthour]

With no activity from the tuner, the secondary power supplies are in question as well. Check the three regulator transistors, Q19/Q20/Q25. They are reputed to have connection problems.

 

[merlynski]

Greetings!
Get a Service Manual from hifiengine.com (free download, free to register) and build or aquire a Dim Bulb Tester Dim Bulb Tester diagram pictorial... please feel free to copy and post.
What experience do you have troubleshooting electronics? Do you know how to solder and unsolder?