Cerwin Vega HFA21s (amph00009) schematics

NorAndy

Member
2020-03-08 2:51 pm
Hi!

I have an Cerwin Vega! amph00009 (220v version of the amph00008) amp from a CVHFA21s subwoofer that goes into "protect" mode when powered up and stays there.
"Power" and "Protect" LED's lights up when its powered, and "Signal" LED also comes on when a signal is received, but it does not go out of protection mode.

From what I understand, this is a pretty common problem with these amps.
This particular unit has been repaired before and based on the reciept a diode, 2 resistors and 2 transistors was replaced. I was told that the sympthoms was identical the last time as well, and that the"Protection system circuit" was faulty.
Material cost for the 5 components was about 5$, total bill incl labor was 300$.
This was 2 years ago, but the warranty for the repair was only 3months.

So now I was hoping to fix this one myself.
Does anyone have the schematics for this amp, know what parts this "Protection system" consists of or where on the board this circuit is?

Best regards,

NorAndy