Hello,
Having a problem with my Pioneer SX-1250.
I replaced the 4 filter caps, recapped the power, protect, stabilizer and amp PCBs. Upon start up, voltages at VR1 and VR2 are stable (65v) on the stabilizer and voltages are stabile on one of the amp boards VR1 (0 Volts) and VR2 (I set to 75mV) BUT on the other amp board both voltages are unstable and vary widely. Any ides as to what the probable cause is?
Thanks.
Having a problem with my Pioneer SX-1250.
I replaced the 4 filter caps, recapped the power, protect, stabilizer and amp PCBs. Upon start up, voltages at VR1 and VR2 are stable (65v) on the stabilizer and voltages are stabile on one of the amp boards VR1 (0 Volts) and VR2 (I set to 75mV) BUT on the other amp board both voltages are unstable and vary widely. Any ides as to what the probable cause is?
Thanks.
I'm working on my SX-1250, too. Having the same issue except on one amp board just the DC offset is an issue. When first turned on, bias was set to 75mV and remained stable, the DC offset voltage was erratic, but eventually settled down to 0mv. After approximately 10 minutes, the dc offset voltage reading again started to vary, and the speaker relay kicked in. FYI, I replaces all the caps and transistors Q1, Q2 and Q11 on the board. Any ideas as to where to start? Hopefully we'll get someone to respond to our concerns.