TLC474 Pin 4 resistor? G&S C2000

[damage]

I have this G&S Designs C2000 (GTi G100.2) amplifier that powers up but has alot of noise. Looks like the GND for the left speaker attaches to the same GND plane that the TL494 does. Probably power hit that speaker terminal and burnt the resistor. It had a brown stripe to start, so I substituted a 100ohm resistor. But thought I would check here to see what maybe it's supposed to be.

The amp has alot of noise at the speaker outputs. But I'm not sure if it's the power supply or something else causing that. First, I'd like to have the right resistor in place.

Thanks!

[Perry Babin]

Can you post a photo of the area where the resistor is located and another showing the entire inside of the amp?

[damage]

I had it backwards. It doesn't tie pin 4 to GND. It appears to tie the secondary of the transformer and non-bridging speaker outputs to GND in which pin4 is on.

[Perry Babin]

If it ties the secondary center tap to chassis ground, it's likely between 100 and 1000 ohms. 100 ohms may be a bit low and could cause problems with engine noise. A 1k ohm resistor probably would not have burned by having 12v contact the speaker terminals but if the speaker output shorted to ground, that could have caused a 1k resistor to burn.

Pin 4 of the 494 is likely tied to ground because it's not used.