To all who know their way around poweramp repair, I need some help please.
I have Behringer EP1500 amplifier, that has fault. It worked fine many years, now I get no sound out of it, both channels are the same.
Please see schematics: https://www.dropbox.com/s/9yoho1h44rn65kw/Behringer%20EP1500_SCHEMATICS_REV_F.pdf?dl=0
Toroid is working, 24V fan powers up, but with full speed (from schematics it seems to me that it should start slow, then increase speed as amp heats up). Power supply VCC reads +/- 80V as it should.
But I do not get +/- 15V to preamp stages, so there is some fault with 15V part of power supply.
Looking at schematics, page 3, I should get 15V on connector X17 on channel 2, which connects to channel 1 as X5.
Measuring voltages on 15V rail:
X17 pin1 should read -15V, but it reads -0.8 V
X17 pin2 should read +15V, but it reads +1.92V
Any suggestion what could be the fault? How to troubleshoot this?
I have Behringer EP1500 amplifier, that has fault. It worked fine many years, now I get no sound out of it, both channels are the same.
Please see schematics: https://www.dropbox.com/s/9yoho1h44rn65kw/Behringer%20EP1500_SCHEMATICS_REV_F.pdf?dl=0
Toroid is working, 24V fan powers up, but with full speed (from schematics it seems to me that it should start slow, then increase speed as amp heats up). Power supply VCC reads +/- 80V as it should.
But I do not get +/- 15V to preamp stages, so there is some fault with 15V part of power supply.
Looking at schematics, page 3, I should get 15V on connector X17 on channel 2, which connects to channel 1 as X5.
Measuring voltages on 15V rail:
X17 pin1 should read -15V, but it reads -0.8 V
X17 pin2 should read +15V, but it reads +1.92V
Any suggestion what could be the fault? How to troubleshoot this?