Dead PSU - Zalman ZM600-HP

[JSWashburn]

Hello everyone.

I'll try and keep it short and simple. One night, I came home after a nasty storm only to find my PC turned off. Everything else checked out ok. My monitor, and external speaker system had power. It was just my PC that wouldn't power up. All three were connected to the same surge strip.

After further inspection, I isolated the issue to my Zalman PSU (Model: ZM600-HP) not getting any power. At this point, I noticed that the fuse was blown as I wasn't getting any continuity through it with my volt meter. Secondly, 2 out of 3 CapXon 2200uf & 6.3v caps vented (on the DC side). After doing some research online, they're many reviews that frown on Zalman's selection of components. That, and the fact CapXon is on the craptastic list here...

So here is my question.

Do you think lightning knocked out the fuse and blew just two caps? Or, did the failing caps cause more current to be pulled from the AC side and thus caused it to fail?

All I have on hand is a simple volt meter and an iron. Nothing fancy. I'm a noob when it comes to replacing components. I've attached a picture of the parts in question. The side of the fuse reads T10AH250V.

[Toasty]

Re: Dead PSU - Zalman ZM600-HP

Power spike probably caught the MOV (surge protection device) and that blew the fuse.

The caps were likely already failed. Serendipitous of that storm causing you to open the case.

Check your warranty. You might be better putting things back in order and calling Zalman for an RMA.

If you're not inclined to do so, then we'll need some pics and caps values, makes, and series codes to help you better.

Toast

[JSWashburn]

Re: Dead PSU - Zalman ZM600-HP

Thanks for the reply

Unfortunately, I couldn't locate a MOV on this unit after doing some searching online. In fact, according to this article, my PSU was never built with a MOV. Is that possible?

I really wanted to get this PSU up and running as a spare for when I might need it. Too bad it's more trouble than it's worth.

If you have any other suggestions, I'm all ears.

[Toasty]

Re: Dead PSU - Zalman ZM600-HP

>>Too bad it's more trouble than it's worth.<<



It's $115 at NewEgg...???

So you are not going to fix this?

Toast

[etnietering]

Re: Dead PSU - Zalman ZM600-HP

yeah if you don't want it I'll take it

[JSWashburn]

Re: Dead PSU - Zalman ZM600-HP

Oh, I *want* to fix it! If it wasn't for the crap caps, this would be the best PSU. Period! It's uber quite (in fact, it doesn't make a sound) and provides all the juice my workstation needs.

Slight problem however. I really want to know how a 10 amp fuse popped?? I'm in agreement with you. I think those caps vented some time ago prior to the fuse going out. The residue was not wet, but dry and crusted. I suppose I could recap it for a cost of about $10 (includes S&H) and replace the fuse. But if it pops again... the journey to resolution may start to suck.

At the very worst, it would be a learning exercise.

BTW, is it normal for the giant cap (AC side) to be slightly domed (not perfectly flat)?

[etnietering]

Re: Dead PSU - Zalman ZM600-HP

The input caps should not be domed at the top. However, if it has a thin plastic sheet over the top, that might be domed while the capacitor underneath is fine. If you push down on the top of it (where it's domed) and feel the real top of the cap, you'll be able to tell if it's actually domed underneath.

About the fuse - fuses are dirt cheap, so get a few. Put a new one in (when you replace the output caps), and if it blows again then there's a different problem, but it could fix it and you won't have any other issues. Otherwise you may have blown something else. Pictures would help everybody here help you diagnose your problem.

[ratdude747]

Re: Dead PSU - Zalman ZM600-HP

the fuse probably blew because of a power surge. recap and keep chugging

[JSWashburn]

Re: Dead PSU - Zalman ZM600-HP

Well, there's only one of the large caps. I'm guessing it's the AC input cap. You can see it in the photos taken here at rojakpot's website. In fact, the same ones shown there are what's inside my PSU.

And yes, that cap is slightly domed. I double checked. It's not just the plastic stuff. It's a CapXon 390uF at 420v. LP series. Vent 85°C.

Should I bother replacing it too?

[etnietering]

Re: Dead PSU - Zalman ZM600-HP

yes, definitely replace it. Something like this will do: http://search.digikey.com/scripts/Dk...name=P14097-ND you have to measure the diameter and height, and use the biggest size that will fit. Make sure to get a cap rated at 105C, the Panasonic TS-HC series is what I would recommend.

[Toasty]

Re: Dead PSU - Zalman ZM600-HP

A few scenarios that could take out the fuse:
- If the mains cap was failing (or even if it wasn't), it could have shorted with the surge.
- the PFC MOSFET's might be blown
- The bridge rectifier(s) may be blown
- All of the above

It's a tough decision to figure which path to take here.
On one hand you're looking at replacing a fairly expensive PSU.
On the other, you're looking at roughly $20-25 worth of parts for just the 10 or so caps and the fuse. If the MOSFETS and/or rectifier(s) are blown, that number could double. Add in your time and your skill level. Then what about your equipment? Is the iron of a high enough wattage to handle the task? Does your meter have a diode check function?

Tough call.

Toast

[kc8adu]

Re: Dead PSU - Zalman ZM600-HP

i have seen quite a few of the crapxon 420v caps go bad.
most open but a few shorted.
had a big industrial power supply a while back with 8 of these in the primary bad.
7 open and one dead shorted.
i would have thought motoman/yaskawa would have known better than to trust cheap parts in something like this!

[Newbie2]

Re: Dead PSU - Zalman ZM600-HP

I think it is worth getting replacement caps and a new 10A 250V fuse to attempt to repair that power supply.

[Per Hansson]

Re: Dead PSU - Zalman ZM600-HP

Why not just try replacing only the fuse and see if it powers on?
I mean if it ran fine with the bloated caps before then you should atleast be able to still do a power on test with it...

If it checks out fine then do change the caps, othwerwise as explained it might require a bit of work to figure out what is wrong...

[JSWashburn]

Re: Dead PSU - Zalman ZM600-HP

The original fuse was ceramic. But I'm not sure if it was a fast-blow or slow-blow fuse. Is there any way to tell? If not, what do you guys recommend as standard for a PSU such as this?

Thanks.

[Toasty]

Re: Dead PSU - Zalman ZM600-HP

T10AH250V is a Time-delay, 10Amp, High interrupt current, 250Volt fuse.

Without a manufacturer mark or name and the corresponding chart, decoding these is a PITA! If it was a Littelfuse or Bussman fuse, then looking it up by their charts is straightforward. With this generic Chinese crap, it's an educated guess at best.

DigiKey doesn't show any. Mouser has them in quantities of 1 at a time for $1.28.

http://www.mouser.com/ProductDetail/...z1aZehEbtKQ%3d

Toast

[JSWashburn]

Re: Dead PSU - Zalman ZM600-HP

yes, definitely replace it. Something like this will do: http://search.digikey.com/scripts/Dk...name=P14097-ND you have to measure the diameter and height, and use the biggest size that will fit. Make sure to get a cap rated at 105C, the Panasonic TS-HC series is what I would recommend.

Thanks for the Info.

My only concern however is that part is rated for 560uF while my original CapXon was rated for 390uF. Shouldn't I replace it with part EET-HC2S391KA instead, or does it not matter?

[Newbie2]

Re: Dead PSU - Zalman ZM600-HP

You can use either part, 560uf or 390uf, they would both still work.

[Toasty]

Re: Dead PSU - Zalman ZM600-HP



Ever get this fixed? Progress?

[Splex]

Re: Dead PSU - Zalman ZM600-HP

I have the same PSU as the OP. It has been powered-on and stable for 3 years... until yesterday. Suddenly, it died and exhibited the same behavior as the OP described.

I searched for leaking/bulging caps, all appeared fine.. except for the large input 420V390uF 85C cap. It has a thin black plastic sheet on the end which was bulging ~1mm. It wasn't shorted so I figured maybe it was just a power surge that caused the fuse to burn.

I tried swapping the fuse, and the fuse went out again.
Next, I tested the MOSFETs. Sure enough, one of them was shorted (STF25NM60N). I replaced it with a STP3NK60ZFP from my dead Antec SP-400.

After swapping the MOSFET, it powered up. Output voltage had apparent ripple and there was a faint 'sizzling/buzzing/sputtering' noise. The blue LED lights were also dimming/flickering/sparkling in intensity... I figured maybe the bulging input cap was indeed faulty. So the next thing I did was replace that cap.

After replacing the input cap and MOSFET, the power supply runs stable and silent. Lights no longer flicker.

One question i have: Is it ok to keep using the STP3NK60ZFP MOSFET instead of STF25NM60N? If not, what can I use as a replacement if I cant find the same part?

Thanks for this insightful forum!