Arc Audio ARC2500-CXL startup issue

[brandes.cm]

The amp powers on with both the power and clipping LEDs lit, then shutsdown. It tries to restart then shutsdown. It continues this cycle until it finally stays running. After it operates for a few minutes you can cycle the remote wire and the amp with start up without issue. If you remove the remote wire for a minute or two then it cycles. Sometimes it will cycle once, other times it will be 10 times.

It uses the SG3525a pwm IC.

 

[Perry Babin]

IF you can't get the schematic diagram for this amp, you may be able to use one of the clarion service manuals to get a basic understanding of the power supply circuit. Some of the arc/clarion amps use very nearly the same circuits. The DPX-11500 may be the closest.

Email me if you want it.
babin_perry@yahoo.com

 

[brandes.cm]

Arc won't supply the schematic.

Been comparing the Clarion to this board, seems close except the clarion uses a micro for it's protection circuits.

The amp won't power up if the output is clipped. I set the gain to clip the output and the amp will just continue to cycle off/on, once the signal is eliminated from the input the amp will start up. Letting the caps bleed off makes the condition worse, more cycles to power on.

 

[Perry Babin]

I looked at this amp on ampguts and it stated that the APX1000.2 is the same board. I've emailed that diagram to you. See if they match.

 

[brandes.cm]

That's it, same board.

Thanks again

 

[brandes.cm]

After lifting r128, r181, r110 and r185 the amp will power up every time, but the output is strange. Here is a scope video of it.

http://vid1253.photobucket.com/albums/hh587/brandescm/2012-12-09_10-01-22_529.mp4

 

[brandes.cm]

U19 defective, -VEE would slowly ramp up, not a crisp -10V. Noticed a little heat from the part as well.