Problem with Enermax EG365P-VE

[D-MAN]

Hi! been lurking around this site for quite some time now, learned lots of things... This will be my 1st post...

I have an Enermax EG365P-VE PSu on my PC, when I turn my PC "on" after a long period of not being used, it turns on normally, If I continuously use my PC lets say for a day or so, its fine with no hicups even 24/7...

now here's the problem, If i decided to turn it "off" and turn it "on" a again after a few minutes, my pc will NOT turn "on", I have to wait an hour before I could turn it on again...

I've decided to open up my PSU, I started looking for indications of a leaking capacitor BUT could not find one, my friend told me that a bad cap or caps could be the problem, with no obvious visual signs of a leaking caps, he said I should remove and test "each" capacitor one by one on the secondary side... that's a lot of capacitor to remove and test one by one ! maybe you guys can help as to where to do I start? which caps to pull out and test first...

any inputs?

[KeriJane]

Hi D-Man!

Welcome to the Forum.

That sort of problem could easily be a bad cap in the PSU or the motherboard because caps, especially failing caps are temperature sensitive.
Not all failing caps swell, leak or burst. It is very possible for caps to fail and still look OK.

The easiest way to tell where the problem lies is to try another PSU or try the existing PSU in a different system.

A cursory search for your Enermax PSU seems to indicate that it is quite old.
Is 2001 the approximate vintage of your system?

Having just recapped an elderly PIII PSU, there were only 5 secondary caps of interest in mine. That's not too many, is it?

To actually test the caps, you would need a Capacitance meter. An ESR meter costs more, an Oscilloscope more yet.

If you are intent upon recapping the PSU, you would probably want to start with the caps nearest the yellow, red and orange output wires. As a general rule, the caps most likely to fail will be the ones between 1000uf and 3300uf and rated at 16v, 10v or 6.3v. They will be attached to the circuit traces that connect to the output wires, and to traces that bridge to the output traces through Inductors. These are usually classified as "Low ESR" caps, not the "General Purpose" caps available at Radio Shack.

Good Luck,
Keri

[D-MAN]

@KeriJane,

Thanks for the TIP!

Yes its quite an old PSU model, got it brandnew in 2005... But its still in mint condition for I'm just using it to test brandnew motherboards before being sold, I haven't connected it permanently to a PC before, just now when I decided use it on my dual core and go for a dual PSU configuration rather than buy those expensive dual rail PSUs with only 18amps each more or less on both its 12v rail... the EG365P-VE has 26amps on its single 12v rail, and so as not to overload it, I'm using a second PSU (Zalman 300watts) to power my harddrives, DVDROM/writer and cooling fans etc.

I will try your suggestion, I will connect this PSU on another motherboard.. I will not yet replace any capacitor for it looks to me that everthing is still ok, the PSU doesn't even have any dust in it, I remembered before that this Enermax PSU doesn't turn ON on certain motherboards, where in fact such motherboards would RUN on other PSUs, even generic ones.

I also have a friend who bought an Enermax Galaxy PSU (1000w) that would not turn ON on his brandnew Intel Quad with DFI mobo, but would turn ON on an AMD Phenom with Gigabyte mobo with no problems even if used continuously for a week without being turned OFF, He had it replaced and still the same thing happened, he ended up getting a corsair instead.

I found some infos on the net, It seems that Enermax PSUs have some compatibility issues... here's a couple of links, the first one closely resembles my problem...

http://www.clunk.org.uk/forums/hardw...ity-issue.html

http://forums.hexus.net/abit-care-he...w-problem.html

[KeriJane]

Hi again D-Man!

It might not just be Enermax that's incompatible....

The ATX standard itself has evolved over the years.

From what I understand, the original ATX standard provided most of its power to the +5v rail.

As time went on, more stuff started using +12v and less +5 and +3.3v

Now, with ATX 2.0 the 5v and 3.3v are less and less important, and the 12v more and more.

What's the point? Well, basically, you shouldn't mix "Old" PSU and "New" Motherboard and vice-versa. An "Old" ATX or ATX1.x will not have enough 12v power for new stuff and a "New" ATX2.x PSU might not have enough 5v and 3.3v power for an old system!

Unfortunately, a whole lot of PSUs still on the market are based on older designs with an emphasis on 5v. Getting enough 12v power can be a gamble regardless of the labeled rating (labels often lie).

Oh well,

Have Fun!
Keri

Oh! here's a good ATX link:
http://en.wikipedia.org/wiki/ATX

[D-MAN]

Hi KeriJane,

I'm now using the Enermax as my 2nd PSU to power my hard drives, DVD writer, Vidcard and Cooling Fans and the Zalman as my 1st to power my motherboard... Its working fine now. I did attached the Enermax to power an intel quad to see if it has the same problem and it worked with no problems, stable voltages.

As for using an old PSU with new mobos, I'm not a big fan of the newer dual 12v rail PSUs, the reason is due to the so called "dual rail myth", that's why I'm using a "2 PSU" configuration to power my gaming rig. The link below is an explanation of the dual rail myth.

http://forum.msi.com.tw/index.php?topic=77071.msg543206

the typical rating of a the newer dual 12v rail PSU are:

Corsair 620HX
3.3v - 24A
5v - 30A
12v1 -18A <--- used to power the proc and mobo.
12v2 -18A
12v3 -18A <--- PSU manufacturers are now aware of the problem thats why they now incorporate a 3rd or 4th 12v rail (such PSU are too expensive )

My Two PSU configuration:

ZALMAN 300B-APS (PSU 1) (motherboard, proc)
3.3v -28A
5v - 30A
12v - 18A

Enermax EG365VE (PSU 2-for my vidcard, HDD, CD/DVDROM etc)
3.3 - 32A
5v - 32A
12v - 26A