zx350

[nutxo]

zx350

do these amps need recapped. I was super impressed with that little ti400 and was thinking of running 2 350s if I can find some.

[Mr. Wild]

Yep, they sure do. BUT usually just the 16V 2200uF power supply caps.

[nutxo]

Yep, they sure do. BUT usually just the 16V 2200uF power supply caps.

thnaks, how many in each 350? I still have some around from the 275s I did

[Eric D]

There are 4 in each ZX350.

[imo1]

Not to hi-jack this thread, but whats the deal with re-capping the old school PG amps?
do all amps need this kind of maintenance as i've only heard about it on this forum about these amps?

[ttocs]

the caps they used on some of the amps would start to leak fluid after 10-15 yrs. That fluid can conduct and if it reaches the right/wrong part of the board it will make on HELL of an explosion(no joke).

[Eric D]

Not to hi-jack this thread, but whats the deal with re-capping the old school PG amps?
do all amps need this kind of maintenance as i've only heard about it on this forum about these amps?

If you look around the web, you will find that computer motherboards had this problem as well for a period of a few years. Sometimes capacitor manufacturers don't get their design right and issues form down the road. So far it seems only PG and Zapco have had these issues (I am sure there are more), as they used the same cap from the same source. This is no fault of PG or Zapco, they are just victims of poor quality components from their source.

[imo1]

Is it the 4 caps behind the power input that needs replacing?
Under the right side plexi?

I found a nice tutorial and will give it a go myself since it looks easy enough.
When i remove the cover, should i remove the fan from the cover, or does the fan unplug easily from the board?

[nutxo]

Not to hi-jack this thread, but whats the deal with re-capping the old school PG amps?
do all amps need this kind of maintenance as i've only heard about it on this forum about these amps?

If you look around the web, you will find that computer motherboards had this problem as well for a period of a few years. Sometimes capacitor manufacturers don't get their design right and issues form down the road. So far it seems only PG and Zapco have had these issues (I am sure there are more), as they used the same cap from the same source. This is no fault of PG or Zapco, they are just victims of poor quality components from their source.

yeah epox asus and abit were notorious for it. Its still going on with LCD monitors.

[IsakAlexander]

Just removed the four 2200uF 16v caps, only one were starting to leak. A question: how do I remove the cap rail circuit board? They have been abused and look terrible so must be changed. A few of the smaller 100uf close by were also in a bad state/cooked.

There are three solder points with two pins on each, are these the only ones?

[Eric D]

Use this to remove the cap daughter card...

http://www.chipquikinc.com/store/prod_template.htm

You first remove as much of the OEM solder as you can, then you apply flux and Chip Quik so the joint stays hot and the board will fall out of the amplifier, with no damage to anything. Once you remove the Chip Quik, you then replace with typical solder.

[imo1]

Hi guys, i have one last quick question. What will the difference between 2200uF and 5600uF caps be?
The eletronics store only has stock of the 2200, but can order the others.

Thanks

[Eric D]

No measurable difference in performance, just appearance. Modern 2,200uF caps are about half the height of the older ones, so they look funny in place of the older ones (IMO).

[IsakAlexander]

A few pics, it´s nearly ready to power up.





No Nichicon bashing, please. I like´em.

[LowandLoud]

Looking good.

How come that 2200uF cap reads 1561uF? Are they all just approximate? Like you could get a dozen and no two would be the same.

LL

[Mr. Wild]

Methinks the value would test higher if the test voltage were higher ie. closer to cap nominal 50V.
But I don't know what voltage the fluke meter uses.

[IsakAlexander]

They were all bulging on the top and have had a hard life. I find the Fluke to be quite accurate. I have not measured equivalent series resistance.

Previous owner said he had to have full gain on amp for satisfactory volume.