Antec Earthwatts EA-500 500w PSU

[tazwegion]

Antec Earthwatts EA-500 500w PSU

I picked up a used one of these units recently for my 24/7 Broadcastify streaming computer, voltages checked as well within spec and were stable so in it went only to find it failed within 2 months corrupting the Motherboard Bios as well, thankfully the the MSI Bios-USB trick saved the board and refitting the FSP PSU got the system back up and running.

Inspection on disassembly indicated no obvious points of interested except for the domed 400v 330uF mains capacitor (this PSU is designed to utilize a single input capacitor) which if you look closely at the uploaded images below appears to have a wrinkle like surface as well.

The filter capacitors all appear in good condition.

Once removed I attempted to do a voltage leak test and noted it wouldn't even hold a charge, I'm guessing I've found my smoking gun...

Any thoughts?

[stj]

Re: Antec Earthwatts EA-500 500w PSU

the wrinkles and unsmooth finish are a sign of heat - lots of heat.
it must have totally boiled internally.

open it for a look!

what make & series are they using in earthwatts btw?

[tazwegion]

Re: Antec Earthwatts EA-500 500w PSU

The primary capacitor that has died was a Nippon Chemi-con SMQ series (rated to 85c), whilst the remainder look to be Ost's, this board appears older than I originally thought with "ATX400w revision 5" clearly marked on the PCB along with the date 25/09/2006.

[Pentium4]

Re: Antec Earthwatts EA-500 500w PSU

Still a possibility it had too much voltage go through it? I have a hard time imagining that cap getting that hot without something else burning first. Is it 270uF?
Beware of the conductive glue.
As a good measure if you want to keep using it, at least replace the OST on +5VSB and 12V. It's a good design so those OST can actually last quite a while but I don't trust them on the two mentioned rails

[tazwegion]

Re: Antec Earthwatts EA-500 500w PSU

No the primary capacitor is actually rated for 330uF, as for the OST's they would be replaced as a matter of course, I should still have sufficient SamXon's on hand...

[mockingbird]

Re: Antec Earthwatts EA-500 500w PSU

I thought the EA-500 was a CWT design (Whereas the 500D was Delta)...

[everell]

Re: Antec Earthwatts EA-500 500w PSU

Picked up this "dead" Antec EA-500 from a computer shop. Had two bulging OST capacitors.....3300 uF/16 volt pi input filter cap on the +12v rail, and 1000uF/16 volt pi input filter cap on the -12v rail. Also a burned area on the pc board where fan control circuit is located. The fan control transistor was not shorted. With pc board out of the case and bulging capacitors replaced, the output voltages came up as: 12.14v, 4.87v, 3.174v, 5.01vsb. Voltage on the main capacitor was 167v off and 377v on.I am still tinkering with it, perhaps more later. I am including a drawing of the fan circuit....which seems to be a new idea.

[everell]

Re: Antec Earthwatts EA-500 500w PSU

a few more pictures........

[stj]

Re: Antec Earthwatts EA-500 500w PSU

here is my prefered fan circuit.

+12v o-----------------------------------------o FAN
gnd o------------------------------------------o FAN

[c_hegge]

Re: Antec Earthwatts EA-500 500w PSU

I had an EA-500 with exactly the same damage once before. My solution was to recap it, remove the transistor, and add the fan controller daughterboard from a dead FSP Power supply. And no, I never disable fan controllers. I do sometimes add them to PSUs that lack them, though.

[everell]

Re: Antec Earthwatts EA-500 500w PSU

Looking at the schematic, the fan controller seems to be controlled by the amount of power delivered on the 12 volt rail. As more power is delivered on the +12 volt rail, the voltage will begin dropping a little under the load, and the fan will come on and deliver more cooling air. The problems on my power supply were......first, the capacitors that failed were NOT on the 12 volt rail (they were on the 3.3 volt rail and the -12 volt rail). Both were located next to each other.....does this indicate a hot spot location? Second.....the pc board under the fan controller transistor was burnt. Does this mean that the fan was on too much and too long........causing too much current for a small transistor like this? Since the transistor is still good, the burn must have occurred over a large period of time.

So what do you guys think of a fan controller that controls based on the loading of the +12 volt rail as opposed to controlling based on a heat sensor?

[stj]

Re: Antec Earthwatts EA-500 500w PSU

you MUST use a heat sensor because it's got multiple heat sources and also you must remember that it doubles as an extractor for the hot air in the case.

[everell]

Re: Antec Earthwatts EA-500 500w PSU

you MUST use a heat sensor because it's got multiple heat sources and also you must remember that it doubles as an extractor for the hot air in the case.

So where is the heat sensor on the EA-500???????????

Did I miss something in the schematic?

[stj]

Re: Antec Earthwatts EA-500 500w PSU

it's a bad design probably - only about half the psu's i see use a temp-sensor.
and half of those mount it on the secondary heatsink instead of mounting it in the airflow.

[ben7]

Re: Antec Earthwatts EA-500 500w PSU

SMQ is only rated for 2000hrs at 85C, this one has a black sleeve so I don't suspect it is a fake, it looks like the vent is the proper shape also.
But, is it just me or do the PFC coils in some antec PSU models run really hot?!

It's possible that the capacitor failed because of normal wear, and then when the ESR increased, it made it heat up more and the plastic sleeve could have de-gassed and caused those bubbles. I guess the silly fan controlling scheme didn't help with the heating issue at all in both cases here...

[stj]

Re: Antec Earthwatts EA-500 500w PSU

they probably run hot given i'v seen a few with burned-out coils.

[momaka]

Re: Antec Earthwatts EA-500 500w PSU

I know Behemot (and probably some others here) will throw a rock at me for saying this, but... APFC is nothing but trouble IMO. If you live in a country with 220/230/240 V AC, just take out the APFC and run the bridge rectifier output straight to the cap leads. I bet you even a stinking CapXon will hold up fine as the primary cap after this mod (not that I would recommend you ever use CapXon as a replacement cap ).

[Pentium4]

Re: Antec Earthwatts EA-500 500w PSU

^ Mostly agree. If properly placed, I'd take a PPFC coil over APFC.

[tazwegion]

Re: Antec Earthwatts EA-500 500w PSU

Well the parts I needed arrived and I had some spare time so I got stuck in hoping to finish this little project off today however... life happens and an interruption lead me to experience a conundrum.

I had 3 capacitors left to replace 2 2200uF and 1 3300uF 10v, using memory, old parts and the process of elimination I'm 99.9% sure I've got the correct locations sorted and using one of everell's pictures have illustrated their placement (the 3300uF appears larger than the 2200uF in the foreground).

Could anyone confirm that these are indeed correct? TIA

[selldoor]

Re: Antec Earthwatts EA-500 500w PSU

Everall says his 3300uf was 16v??