Help repairing a CS-400


2008-02-16 8:54 pm
I have a CS-400 amp that i have been working on. It had 3 bad transistor 1 driver and 2 finals in the B ch. and a 100 ohm 1/4 watt resistor was burned out so badly that it was comepletely gone. When i started working on this Amp i found around 57 volts out on the B ch output. I ordered all new transistor for the Amp 4 drivers and 12 finals and replaced the burned out 100 ohm resistor. Before installing my new transistors i moved the 3 needed transistors from the a ch that worked 100% to the b ch. Upon power up the amp worked for about 1 min and then..... Sparks flow. Upon inspection i found that the 100 ohm resistor was gone again (burned away) and a small transistor on the driver pcb has a big hole burned in it.

I found a very poor quanlity diagram on the internet that is so small i can't read it. If someone has a diagram that they would be willing to share that would be great. My CS-400 is an "A" ver i thank it has "11178" on the driver broad and "22278" on the power boards, would the 78 be the year it was made???

Any help would be great. I has spent a lot of time in these forums reading and it has helped so far.

Thanks for your time

Gary LaForce