Power Acoustik ps4-600 dead

[mbates14]

Ran into one of these to repair. it is totally dead. no action from the SMPS. Cannot find a schematic or data on this amp. So i am looking for anyone that is experienced in this particular amplifier.

I checked all power and output transistors plus various other components and everything appears to be fine. even replaced the TL494 with a known-good one. dead....

I noticed that TL494 Error amplifier 2 is positive-going true output. thus inhibiting the SMPS from running. negative input i think is pin 15, is a rock 5V from the reference generator. then the positive input pin 16, is sitting around 9V. this causing the output to be 1 from the comparator, and inhibiting operation. I have traced that whole circuit and i am comming up with nothing. If i cross-out pins 15-16 this disabling the comparator, the SMPS will power up, power LED green and no protect LED kicking in either. havent tested for sound, as i didnt want to use it for long with a disabled error amplifier circuit. I guess the error amplifier is used for self-regulation, but im not sure, however that circuit appears to be malfunctioning.

any ideas?

[mavric]

Honestly, you can get a new one for 60usd. It is a junk amp, over rated and under powered, this is probaly why you cannot fix it. Power Accoustic tends to use cheap parts but the same chassis for their amps. I would just get another 4 channel with a warranty, not domething someone put together just to make sound. just my opinion, Mavric

[mbates14]

oh, ill repair it. watch me..... hey however thanks for your opinion anyway...