CS 800 fan switch light?

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Rhythmmakers
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Joined: Sun Jan 19, 2020 7:56 pm

CS 800 fan switch light?

Post by Rhythmmakers » Wed Mar 25, 2020 4:43 pm

i have a cs-800 old style that the hi/lo fan switch does not light up.
the fan works as it should using the switch for high and low.
everything else works fine.
i replaced the power switch with the fan switch to see if the fan switch was bad but the light comes on when used as the power switch.
so with the elimination of the switch itself being bad what would be my next thing to check?

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Enzo
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Re: CS 800 fan switch light?

Post by Enzo » Wed Mar 25, 2020 9:12 pm

Nothing. The light comes on when the amp is overheated and turns itself off but for the fan. Look at your schematic. There are two thermal switches, one on each heat sink. If one overheats, it opens. the two are in series. See the "high temp" light above the fan and thermal breakers? The way it is wired, those thermal breakers open when overheated, removing power to the amp circuits. But the fan is wired in before those switches, so the amp shuts off but the fan continues to run, hopefully cooling the amp back down.

Usually they were blue wires, but could be other color. Look on your heat sinks for a small thermostat. Seems to me they were bolted right atop one of the power transistors. Pull one wire off one of them, and carefully tape the end so it touches nothing. Now does the light come on?

Rhythmmakers
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Joined: Sun Jan 19, 2020 7:56 pm

Re: CS 800 fan switch light?

Post by Rhythmmakers » Thu Mar 26, 2020 7:29 am

WOW!
So i removed one wire like you said and the light came on.
Good information.
Thank you very much.

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