Problem with an XSITE XAD2K vehicle amp

[Jack Crow]

Hi all,
Got this repair for a client and need a clue.

Who has a good 2200uF cap at 80 volts that will fit in a space of 1.02 inches round by 1.22 inches tall.

This thing lunched three of these, if I have to take it all apart, Im going to change every last one.

Open to ideas.
If you need photography that is not hard to do.
Mike

[japlytic]

Re: Problem with an XSITE XAD2K vehicle amp

I found that an 85C Chemi-Con SMH (part ESMH800VSN222MQ30S) would fit - what is the temperature of the original units?

[Jack Crow]

Re: Problem with an XSITE XAD2K vehicle amp

J,
Taught me something new.
I never noticed a temp rating on the on the parts, but it's there.
It reads 85 degrees C.

I found some parts that would fit on Mouser for about 4 bucks each.

The next problem was how to get the board out.

The transistors are held to the heat sink by some very stout spring clips.
With a stiff screw driver I can bend the clip out of the way, but there are 7 clips on one side, and 9 on the other.
They have no interest in sliding out of their positions, it's as if they were press fit into place.

Is there a special tool I can buy to release these clips?

Thanks in advance.
Jack Crow

[Jack Crow]

Re: Problem with an XSITE XAD2K vehicle amp

J
As one of the gun guys I know is fond of saying....

"This post is worthless w/o pictures".
Just took some.

http://www.flickr.com/photos/9010884...th/8095470001/

Let me know what you think.
Im stuck on how to remove those clips.

Jack Crow

[kc8adu]

Re: Problem with an XSITE XAD2K vehicle amp

they should just pull up.
if you can get 105c caps do it.
they have a rough life in boom car amps.

[ben7]

Re: Problem with an XSITE XAD2K vehicle amp

Interesting 'DKE' brand caps!

It looks like somehow to clips go into the heatsink. Do they get screwed down on the back of the heatsink? Are they bent over the back of the heatsink? (I.E. do they have a little tab -that goes into a hole in the back of the heatsink- which is bent over?)

[gilly1984]

Re: Problem with an XSITE XAD2K vehicle amp

them clips are a pain to get off. use a flat head screwdriver and just keep teasing each clip, they will pop off. hurts your palm when putting them back on.

[Jack Crow]

Re: Problem with an XSITE XAD2K vehicle amp

Ben, KC8 and Gil,

They slot into the main heat sink, no screws or hardware.

One of my buds in the auto sound biz said to drop some oil into the joint.
That is good thinking.
Steel clip in an aluminum heat sink is a recipe for bi metallic problems.

Will make the run to Home Depot (US based hardware store chain) up the road and buy a stout screw driver.

I think I can make due with the 'needle nose' vice grips I already have.

Getting the clips back on, is going to be a cast iron female hound.

Guys, Thanks for the tips, will give it a try.

Jack Crow

[Jack Crow]

Re: Problem with an XSITE XAD2K vehicle amp

Guys,
The tool dealer paid off.
Got some bigger tools and that seems to have been the trick.
The board came right out.

New photos are at the end of the current set. The last five. The first few are going to be 're runs'.
http://www.flickr.com/photos/9010884...7631787506891/

That nasty hooked tool is for removing cotter pins.
Might be better for forcing confessions from them.

Anyhow, the board is out, I pulled the six caps that looked bulged.
They are split three and three. Popped and more or less working according to my esr meter.

So if this is a bi polar supply, one side failed hard.
Over the weekend I am going to check the transistors (lots of power fets) and the fast recovery diodes. My gut says ripple blew the caps.

Some surprises.
The board is flimsy. If im not real careful I can snap it. There is a huge amount of weight with the transformers but still.
The gauge reads .07 inches.

Another thing is the fusing. It has five 'thirty amp' fuses in parallel.
That is a lot of dam current. My bench supply is good for about 30 amps.

Last item, the board was less than clean. As if the OEM failed to remove the flux. Gross. At least it cleaned up in Iso Alcohol.

That is the news of the moment.

Dreading the time when the clips need to go back on.

Keep it safe
Jack Crow

[Jack Crow]

Re: Problem with an XSITE XAD2K vehicle amp

Hi all,
Follow ups.

Installed the caps today. Ended up using six of the puppies.
(CDM 380LX 2200uF 80WV +85 degree C units. )
Cut off the excess lead length.
Cleaned the circuit board.

Figured out how to put the spring clips back on the power transistors.
(Drive bar and a tap hammer!)

Had to fabricate up some harness wires for testing.
First to feed my audio generator into this things RCA inputs.
Then to hook up the power feed to my bench systems plus a remote switch simulator.

Fired the thing up.

It seems to work.

No explosions.
No sparks.
No smoke.

Not at all what I call exciting.

What I can't find is my audio power load.

So with very little in the input (aprox -30dB), centered at 40hz I get a huge amount of open circuit output.
In the range of 50 volts.
That is a lot of gain.
Then again this thing is some kind of 'sub amp'.

That will drop a bit when I get a load on it.
Going to let it run for a few hours on the bench to make sure the new caps stay good.

This was a different kind of assignment for me.
When I play in audio it's with more or less normal stereo gear, dedicated sub amps are something I just going to have to get used to.

Thanks to one and all for the inputs and insights.

Keep it safe
Jack Crow

[redwire]

Re: Problem with an XSITE XAD2K vehicle amp

Great pics and repair work, that's quite a big car amp. I haven't seen dual-transformers or 5-pair output transistors in a car amp. That's enough to destroy my eardrums....
What replacement caps did you end up using?

[redwire]

Re: Problem with an XSITE XAD2K vehicle amp

Oops, I just saw the Cornell Dubilier part#CDM 380LX 2200uF 80WV +85C you used. Had no idea they made small, low profile parts. I think they are among the best for this application.