Sony XM-1004gx

[mike49504]

I got this amp in for repair and it appears to be powering up but no output on all 4 channels.

Heres a couple pics of the amp wondering where i start to check.

[Perry Babin]

Have you checked all pots and switches?

Drive a strong signal into the front channels. Do you have signal on pins 1 and 7 of IC813 and IC814?

[mike49504]

Checked all pots and switches.

No singal on pins 1 and 7 IC813 and no signal on pins 1and 7 IC814

[Perry Babin]

Do you have ±regulated supply voltage on the op-amps?

Do you have signal on pins 1 and 7 of IC801?

Do you have signal on pins 1 and 7 of IC805 (on the crossover board)?

[mike49504]

I have + - 14.50 volts on IC'S 813,814,815.806.

No regulated voltage on any of the op amps on the crossover boards. Also no signal on 801 and 805

494
1:13.23
2:2.52
3:4.59
4:0.32
5:1.66
6:3.76
7:0
8:13.88
9:0
10:0
11:13.88
12:13.88
13:5.02
14:5.02
15:2.52
16:.03

[Perry Babin]

On D812 (under the transformer), what is the DC voltage on legs 1 and 2 (see attached image for pin numbers)?

You may have to check it with a few seconds of powering it up if both are near 0v.

[mike49504]

I tryed testing them on leg1 i got -.026 the first time i did it but now i get 0 volts on legs 1 and 2 and tryed it a few different times and get 0 volts on both legs.

I measured whithin a few secs upon powering up.

[Perry Babin]

Measure the DC voltage on leg 1 of the 494 again. Is it still ~12v?

[mike49504]

yes pin 1 is on the bottom or top of the c494?

[Perry Babin]

Bottom left. It appears that you had the numbering correct.