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wrek · 06-05-2012, 09:12 AM

Hi everyone.
My Power switch light burned out on my 50 Watt JCM 800, so I ordered a replacement switch.
On the amp Chassis a label says USA 2205 02/04/86 for the year it was built.
The old switch is a five wire, and the new one is a four wire.

I found this diagram showing how to convert the wiring for the new switch, so it may be useful to anone with the same problem.

http://www.amprepairparts.com/sw491wiring.gif

Thanks.

Update:
I removed the wires from the old 5 pin RED Power switch, one at a time, and "thought" I soldered them one at a time, exactly as shown in the diagram, with the exception being that my amp does not have an orange wire on pin 11. Mine is blue and goes to the transformer.

For some reason, now my standby switch is reversed. When it is in standby, the amp comes on, and turns off when the switch is set to on. I did not remove or rewire the standby switch. The amp works, but there is a hum present that is not what I normally hear when I turn it on.

I think I may have possibly screwed up, but I can't find any diagrams with my wiring colors to be sure. I was thinking that perhaps I inverted the switch, but the diagram on the link above seems to be oriented the same way. The only difference is the second blue wire going to the transformer.

Does anyone have a clear diagram of exactly where the wiring goes from the switch? Maybe my amp was modified before I bought it, or maybe I just wired the switch upside down? (I didn't think it mattered on a 4 pin rocker switch, but I could be wrong).

I am not sure how to upload an image from my documents. The image button here only allows from a URL, so I will just type out how I wired the switch.

Here is what I have on my amp connected to the new switch:

Pin 12 Blue to Mains input Pin 25 Brown to Mains Input
Pin 11 Blue to Transformer Pin 26 Yellow to 3 Amp Fuse

The old switch had the black wire, which I cut and taped.
Blue Brown
Blue Yellow
Black

Any input is appreciated.
Rek

06-05-2012, 09:12 AM	#1 (permalink)
wrek Junior Member Join Date: Jun 2012 Location: New York USA area Posts: 12	Rewiring a JCM Power Switch Hi everyone. My Power switch light burned out on my 50 Watt JCM 800, so I ordered a replacement switch. On the amp Chassis a label says USA 2205 02/04/86 for the year it was built. The old switch is a five wire, and the new one is a four wire. I found this diagram showing how to convert the wiring for the new switch, so it may be useful to anone with the same problem. http://www.amprepairparts.com/sw491wiring.gif Thanks. Update: I removed the wires from the old 5 pin RED Power switch, one at a time, and "thought" I soldered them one at a time, exactly as shown in the diagram, with the exception being that my amp does not have an orange wire on pin 11. Mine is blue and goes to the transformer. For some reason, now my standby switch is reversed. When it is in standby, the amp comes on, and turns off when the switch is set to on. I did not remove or rewire the standby switch. The amp works, but there is a hum present that is not what I normally hear when I turn it on. I think I may have possibly screwed up, but I can't find any diagrams with my wiring colors to be sure. I was thinking that perhaps I inverted the switch, but the diagram on the link above seems to be oriented the same way. The only difference is the second blue wire going to the transformer. Does anyone have a clear diagram of exactly where the wiring goes from the switch? Maybe my amp was modified before I bought it, or maybe I just wired the switch upside down? (I didn't think it mattered on a 4 pin rocker switch, but I could be wrong). I am not sure how to upload an image from my documents. The image button here only allows from a URL, so I will just type out how I wired the switch. Here is what I have on my amp connected to the new switch: Pin 12 Blue to Mains input Pin 25 Brown to Mains Input Pin 11 Blue to Transformer Pin 26 Yellow to 3 Amp Fuse The old switch had the black wire, which I cut and taped. Blue Brown Blue Yellow Black Any input is appreciated. Rek Last edited by wrek; 06-05-2012 at 09:00 PM. Reason: Need to add something.