SONY XM-3520

[stuparumihairadu]

Hello all,

I am undergoing an audio project after I found this amp for like 8 $.

Looks ok inside of it.

Had 1 of the 2 capacitors missing (the ones after the dc input). Replaced it.

Surprise surprise, after I replaced it, I got the schematics for it, and saw that it need 2x10mF (or something like that), and I have 2x15mF. I instaled the one missing after the one allready there.

I can change the capacitors no problem.
The only thing..hooked it up to the battery charger...and both the protection and power mode are on.

I did measure the tansistors with the multimeter in off mode, and saw that they are all ok. None damaged.

Need help on it beeing put back into work guys.
I own a VW Lupo, so I could really use this little amp to power up the audio in the car.

 

[Perry Babin]

I don't have that service manual. Send me a copy and I'll try to help.

babin_perry@yahoo.com

 

[stuparumihairadu]

here is what I could find. is it enough?

 

[Perry Babin]

What is the DC voltage on either terminals of L101 with the amp powered up and all components installed?

DC voltage on collector legs of Q104 and Q105?

 

[stuparumihairadu]

I can`t seem to find q105...WTF !!!

 

[Perry Babin]

It's likely under the board.

 

[comanr]

I am not sure this makes any sense after all this time, I have the same amplifier , all transistors seemed to be ok, power ok, I simply bypassed the protector circuit and the amplifier works like new, I think the IC responsible with protection is faulty, thank you.