Having problems troubleshooting a MXR 10 Band EQ

[Rambozo96]

Picked up an old blue MXR 10 band EQ for a repair and all it does is emit a loud hum. No signal just hum. Tested the electrolytics and tantalums and couldn't find any caps wildly out of spec or totally dead. The opamps power rail seems to be getting about 5.85vdc and ground-5.85vdc. Is there a way to test an op amp to make sure it's passing signal like it's supposed to? I'm really at a loss as to what else could cause the problem. I disclosed the schematic but it appears mine steps the voltage down to 12VAC instead of 15VAC like the schematic shows.
Thanks in advance

[Slowpoke101]

Check for a shorted or open circuit diode in the bridge rectifier BD1 - I think. The schematic's detail is a bit poor. You appear to have low rectified voltages so check it out.

[Rambozo96]

Voltages out of the bridge rectifier shows +10.88VDC and-10.86vdc. The voltage drop doesn't seem to occur until after the 100ohm resistors because the voltage readings past those resistors is +5.5vdc and -5.47vdc.

[Slowpoke101]

The voltages out of the bridge rectifier are very interesting. Which now lead to this question - Is the transformer rated for 220 or 240V AC (mains voltage ) and are you plugging it into a 110V AC outlet?

[PRR]

The raw DC at C26 C27 should be + and - 20V, not 10V.

1) You using a 220V supply in a 110V land

2) C26 C27 are totally shot. This would give a pulsating waveform which would be 13V, but some meters may not handle the pulsations the same way and some may read low.

Use AC Volts and read the two 15V AC ends of the power transformer.