Want to Repair Cadence TXA-1000D amp

[gexamb]

i have a cadence txa-1000d 1000w @ 1ohm amp (i believe 700w @ 4R).
the problem is that the amp will just not turn on at all. sometimes the green light comes on indicating that the amp is on. sometimes it does not turn on. in any case, there is no power output to the subs. i have not measured anything because my multimeter can only measure up to 10 A so it would fry it basically.

i have posted some pictures of the amp internals, and from what I can see there is nothing burnt, browned, melted, discolored, no broken transistor legs, nothing seems out of the ordinary basically, but then again im no expert. so maybe these pictures can give you a hint as to what is going on.

what things should I look for and how do i go about testing this amp? i know it is hard without a schematic, but i will try and look for one.

thank you.

picture links:

http://www.diyaudio.com/forums/showp...2&postcount=15

http://www.diyaudio.com/forums/showp...5&postcount=16

[gexamb]

no luck on any schematics. anyone? paging Perry Babbin

[Perry Babin]

I'm not familiar with the amp. Can you post a photo of the inside of the amp?

[gexamb]

i have posted pictures. the links are in my first post.

and BTW theAnonymous1 referred me to you. said and quote "There is a very nice and knowledgeable fellow there named Perry Babbin. If he can't help you fix the amp, no one can. "

lol.

[Perry Babin]

Sorry I didn't notice the links to the photos. Maybe theAnonymous1 should add half-blind to the next recommendation he gives. :)


It looks like a clone. Give me the DC voltage on the 16 pin SG3525 power supply driver IC. If they are using a TL494 or a TL594 in the power supply, the pins are numbered the same way. Place the black meter probe on chassis ground. Place the red meter probe on the point where you need to measure the voltage. The amp will have to be powered up, including remote. I'd suggest that you insert a 10 amp fuse in the B+ line to help prevent damage if you accidentally short two pins together when measuring the voltage.

The following PDF file shows the way the pins are numbered:
http://sigma.octopart.com/14277/data...s-SG3525AN.pdf

IC#
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:
Pin 15:
Pin 16:

[gexamb]

could i use a 6amp 12V battery charger to power the amp? i dont feel comfortable doing it in my car with the case open. this is what the charger looks like. thank you my friend

http://www.autozone.com/autozone/cat...ame=Schumacher

[Perry Babin]

The battery charger may produce a lot of hum/noise and the voltage may be well above 12v.

Do you have any large capacitors that you could connect across the output of the charger so you could check the DC voltage before connecting it to your amp?

[gexamb]

i have to say no i do not, but it also has a 2amp 12V setting as well that i can set it to and a 6V 2 amp setting as well. i will check the levels with my dmm on a low amp setting and it should not fry the DMM hopefully.,

[Perry Babin]

You don't want to use the multimeter in 'amp' mode. Connected across the output of the charger, you're likely to blow the fuse in the meter or damage the meter. Set it to DC volts. If it's not auto-ranging, set it to the 20v range.

With the charger set to 2 amps, it's not likely to have enough output to power the amp.

Do you have an old computer power supply that works?

[gexamb]

yes i do i forgot about that but i just dont know how to start it (turn it on )with out it connected to a pc