MTX 801D Amplifier Cap Help

[willne1]

Hello All...this is my first post here and I'm a newbie at cap replacement so please be a little patient with me. This amp was working and now it will not power on. I removed the cover and noticed some of the caps are bulging and the two bigger ones in the picture have flaking skins and tops (no bulging) but other than that they look o.k. with a visual inspection by me. I would like to ask you guys what caps to use to replace the smaller caps and should I replace the two big ones? I can't seem to find an exact replacement for the six smaller ones, they are Nichicon ZA stamped on the side 470uf63v. The big ones have no name as far as I can see but they are stamped 50v 2200uf and the numbers 28c03l are on them.

I'm having trouble getting the image to upload I'll try again in a few.

TIA
willne1

[Logistics]

Re: MTX 801D Amplifier Cap Help

Just upload the image to imageshack.com and then link it.

There are a slew of good replacement capacitors. Personally, I use Panasonic FM or FC from Digi-Key whenever possible, but they are not the only good cap. First thing you'll need to do is figure out the diameter of said caps. I'll just go with FM's and FC's for the moment since I can't find information about Nichicon ZA's.

In FC's you can find 470uF 63V in 12.5mm diameter and 30mm height or 16mm diameter and 20mm height. The 2200uF 50V can be had in a 18mm diameter and 35.5mm height. Couldn't get these in FM's.

What are the values on the smaller caps?

[willne1]

Re: MTX 801D Amplifier Cap Help

Thanks....here's the link....http://i196.photobucket.com/albums/aa15/willne1/328.jpg

[willne1]

Re: MTX 801D Amplifier Cap Help

Do you think I should replace the two big ones?

[PlainBill]

Re: MTX 801D Amplifier Cap Help

Do you think I should replace the two big ones?

Dude!!!

Those are Nichicon VZ's, not ZA!! Nichicon HE or PW series should be a step up, but perhaps you should let the capacitor experts weigh in.

My inexpert opinion is the two large caps got unpleasantly hot. Definitely replace them too. Call it your own little stimulus effort - when the Dow hits 20,000 in 2012 you can claim you did your part.

Now those four very large caps way in back. Is the third from the left bulging, or is that the cord behind it?

PlainBill

[Toasty]

Re: MTX 801D Amplifier Cap Help

<<----- Hands PB his glasses...

It's the cord.


@willne1-

Some overhead pics or a slightly higher angle would be better, plz.

[Wizard]

Re: MTX 801D Amplifier Cap Help

that secondary caps, replace them all.

Cheers, Wizard

[willne1]

Re: MTX 801D Amplifier Cap Help

This is the only other pic I have. If needed I can take more tomorrow. That is a cord in the back those caps look fine to me. Thanks to all for helping, what do i get to replace the two big ones that are shedding? http://i196.photobucket.com/albums/aa15/willne1/330.jpg

[PlainBill]

Re: MTX 801D Amplifier Cap Help

This is the only other pic I have. If needed I can take more tomorrow. That is a cord in the back those caps look fine to me. Thanks to all for helping, what do i get to replace the two big ones that are shedding? http://i196.photobucket.com/albums/aa15/willne1/330.jpg

DamnifIknow. I tried using my crystal ball, but it's in for repairs (the caps are fine).

Try to get pictures that show both sides of the cap. Again, Value, Voltage, and Series.

PlainBill

[linuxguru]

Re: MTX 801D Amplifier Cap Help

Large Nichicon VZs from that era were prone to leaking from the bottom bung - definitely replace them with Nichicon Muse (FG, KG, KZ, ...), Panasonic FC or Rubycon ZA/ZL. There are various other choices in the price/performance spectrum - starting with Black Gates and other snake-oil at the top of the price band.

[kc8adu]

Re: MTX 801D Amplifier Cap Help

i would not waste audiophool grade parts on a noisemaker amp.
i use a lot of fc in the smps section in these when i service them.better than what comes stock.
the guys that use them are half deaf anyhow!its fine if it goes boom boom.

[willne1]

Re: MTX 801D Amplifier Cap Help

I took some more pics today, hopefully I can get an idea on what to get to replace the two that are pealing.

http://i196.photobucket.com/albums/a...1/P1000426.jpg
http://i196.photobucket.com/albums/a...1/P1000423.jpg
http://i196.photobucket.com/albums/a...1/P1000422.jpg

[PlainBill]

Re: MTX 801D Amplifier Cap Help

I took some more pics today, hopefully I can get an idea on what to get to replace the two that are pealing.

http://i196.photobucket.com/albums/a...1/P1000426.jpg
http://i196.photobucket.com/albums/a...1/P1000423.jpg
http://i196.photobucket.com/albums/a...1/P1000422.jpg

It appears the two big ones are United Chemi-Con SMH series. They are available from Digikey (565-2664-ND) for $2.58 each. I'll let someone else identify a better cap.

PlainBill

[kc8adu]

Re: MTX 801D Amplifier Cap Help

looks like those are on the +12 input.
suckers got hot!maybe reversed polarity?
take a shot at the bottom of the pcb centered on those 2 caps.

[PlainBill]

Re: MTX 801D Amplifier Cap Help

I took some more pics today, hopefully I can get an idea on what to get to replace the two that are pealing.

I just realized this is for a car. Make sure the replacement caps are the same dimensions as the original!

Oh, bells peal. Apples, bananas, oranges (and caps) peel.

PlainBill

[Toasty]

Re: MTX 801D Amplifier Cap Help

Please measure the clearance for replacement caps. Going by the ELNA series LP5's (now LA5) in the background, you should have clearance >35mm high.

Panasonic FC series for the VZ's (12.5x20mm, 640mA ripple) - 470uF/63v - 12.5x30mm, 2090mA ripple - EEUFC1J471L

http://search.digikey.com/scripts/Dk...name=P10351-ND

Nippon Chemi-con SMH (22x25mm, 1.91A ripple) replace with same SMH series but step up to 3900uF/50v - 22x35mm - ESMH500VSN392MP35S - 40% more ripple current @2.65A

{{Shown as xxx35T by Digi - Manuf site catalog shows xxx35S? Dimensions are the same.}}

http://search.digikey.com/scripts/Dk...me=565-2666-ND

[willne1]

Re: MTX 801D Amplifier Cap Help

looks like those are on the +12 input.
suckers got hot!maybe reversed polarity?
take a shot at the bottom of the pcb centered on those 2 caps.

Here's a shot of the bottom. Once again thanks to everyone for the help.
http://i196.photobucket.com/albums/a...1/P1000429.jpg

[Toasty]

Re: MTX 801D Amplifier Cap Help

Another thought.

Mind the removal procedures listed on this site:
https://www.badcaps.net/pages.php?vid=32

Those big SMH's apparently (from the photo, ty) have their other lead soldered through to the top side. If you don't apply enough heat to melt the solder on the top side, you could end up ripping the traces off the board underneath them. Do not force them. Rock them gently, towards the other connection, as in step 2. Do not force them. (repeated for effect).

[willne1]

Re: MTX 801D Amplifier Cap Help

O.K. Toasty...thanks for the link. How would you guys recommend I hold this board while I'm removing the caps? It has a funny shape since the regulators are sticking out on the sides and the controls on the one end (see the pic).

http://i196.photobucket.com/albums/a...1/P1000431.jpg

[Toasty]

Re: MTX 801D Amplifier Cap Help

Ummm... Carefully??

Upside down on several towels or foam material to cushion. You can probably stand it up on them on the power connection end if necessary.