Enermax Liberty ELT500AWT fails to turn on

[Mad Professor]

Re: Enermax Liberty ELT500AWT fails to turn on

R14, R15, R24 are all the same (Black, Blue, Silver, Gold, Green).

Please see attached picture as requested.

[Behemot]

Re: Enermax Liberty ELT500AWT fails to turn on

That is broken. The gold one cannot be on 2nd place but black cannot be first either.

[jamesbo]

Re: Enermax Liberty ELT500AWT fails to turn on

Based on the photo, I think it may read:
Brown = 1
Blue = 6
Gray = 8
Gold = x .1
Green = .5%

16.8 ohms at .5% tolerance

or if it is Black:
Black = 0
Blue = 6
Gray = 8
Gold = x .1
Green = .5%

6.8 ohms at .5% tolerance

[Behemot]

Re: Enermax Liberty ELT500AWT fails to turn on

One seems a little bit brown, bot on the other resistors it is 100% black…

[everell]

Re: Enermax Liberty ELT500AWT fails to turn on

Most likely that black is actually a brown color that has been cooked from heat. The value is 0.16 ohm 5%. The green band is a manufacturer type indicator. Rather common resistance value as current limiter for the power transistors. Voltage developed across this type resistor is used to set the shut down point. The Blue ESR meter can measure it, but an ordinary ohmmeter will show it as a short.

Were any of the power transistors shorted? Was the fuse open?

[Mad Professor]

Re: Enermax Liberty ELT500AWT fails to turn on

My DVM/DMM that I am using for testing is a UNI-T UT58C.

There are no shorts on any of the K2607 or IRFP460A pins.

What fuse? the main input fuse on the PSU? if so that one is fine.

[Mad Professor]

Re: Enermax Liberty ELT500AWT fails to turn on

Very intresting.

Today I have put eveything back in the PSU, and soldered it all back up.
And would you guess it, the dam thing is working again.

Just tested the voltages from the psu output and I get the following.

+5.0Vdc = +5.03V.
-5.0Vdc = NA.
+12.0Vdc = +12.78V.
-12.0Vdc = -12.13V.
+3.3Vdc = +3.43V.
+5.0Vsb = +5.20V.

ATX PSU voltage details taken Wiki
+5.0Vdc [+/-5%] (+4.75V to +5.25V).
-5.0Vdc [+/-10%] (-4.50V to -5.50V).
+12.0Vdc [+/-5%] (+11.40V to +12.60V).
-12.0Vdc [+/-10%] (-10.8V to -13.2V).
+3.3Vdc [+/-5%] (+3.135V to +3.465V).
+5.0Vsb [+/-5%] (+4.75V to +5.25V).

Also eveytime that this PSU it brought out of standby into full power, there is a crack sound coming from the PSU.

Once the PSU is running there are no strange noises coming from it.

[Behemot]

Re: Enermax Liberty ELT500AWT fails to turn on

Maybe something related to fan start?

[DomRK]

Re: Enermax Liberty ELT500AWT fails to turn on

I have this same PSU, with a blown internal fuse. I think it is rated 15A 250V and appears to be one of these

I assume a glass bodied alternative will be suitable, perhaps one of these,
http://uk.farnell.com/littelfuse/021...ast/dp/1678194

The only compromise I can see is the interrupting rating, where my replacement has a lower rating.

Is this likely to be ok and what are the chances that my power supply will spring back to life with this simple part replacement?

[Behemot]

Re: Enermax Liberty ELT500AWT fails to turn on

Bloody hell, 15A?! No way, it must be 5 A. Check again. This thing has active PFC and thermistor, there is no reason why it should EVER reach 15 A.

[mariushm]

Re: Enermax Liberty ELT500AWT fails to turn on

It's rarely only the fuse. Check the components after it or buy several fuses because you'll pop at least one.

A 15A fuse is pretty much useless, when the house circuit is rated for 16A.. if it was 15a you could almost replace the fuse with a wire and let the house breaker take the hit if it's the automatic kind.
But DON'T DO IT, i said almost. Fuses are cheap.

Being a 500w psu, the most current it should see in its life would be 500w / 110v = ~ 5A . With about ~ 20% extra for margin and poor efficiency, it's still only about 6-7A.
So I don't think it's a 15A fuse.

Depending on how it's made, the psu may see higher currents only when the big capacitors charge up when you plug the power supply in. But that's 8-10A for a few ms.
So I think a 8A slow fuse would probably be more suitable, or maybe a 10A fast fuse.

It should say on the board in some place "for continuous protection against bla bla use a x A fuse ", for example see here in the corner on "Enermax Liberty DXX 500W" model:

http://www.hardwaresecrets.com/fullimage.php?image=9867

[Behemot]

Re: Enermax Liberty ELT500AWT fails to turn on

I think he looked wrong and it is 5 A. No reason even for 8A fuse. It's only bloody 500 W.

What would you want to use for 1500 W, 30 A? Some sense man

[DomRK]

Re: Enermax Liberty ELT500AWT fails to turn on

thanks for the replies, very glad I asked. Annoyingly, the message on the board advises that the same type and rating of fuse is used, but does not appear to give details. You can make out most of it here:
https://www.badcaps.net/forum/attach...6&d=1325773170

So, assuming it is actually 5A, I should be able to pick up a packet of spares from my local Maplin tomorrow. http://www.maplin.co.uk/20mm-glass-quickblow-f-451

I've taken a couple of pictures so you can see why I thought 15A

http://www.flickr.com/photos/84162522@N02/8346999031/

dignity restored...?

[Behemot]

Re: Enermax Liberty ELT500AWT fails to turn on

Maybe it was supposed to be T5A (T, slow)?

[ben7]

Re: Enermax Liberty ELT500AWT fails to turn on

I think it is 5A, and just got scraped a little there when handled.

Check the power semiconductors, the bridge rectifier, and the two light brown ceramic capacitors on the primary side for shorts.

[Behemot]

Re: Enermax Liberty ELT500AWT fails to turn on

Just as an additional information. I got this PSU here. Seems CEC's caps lifetime is just ending worldwide This is 2th PSU with half of the caps bloated and several have been here already.

This one still turns on, but +5 V SB is only 3 V and wheezes.

As for the fuse, I will check mine in 5 minutes.

ADD// So. I have to admit you have been right. This is insane but there is 15A fuse. I discovered that in this version OS NO BLOODY THERMISTOR. Mine 400W version has one. Here is spark gap instead. I don't really like it…seems you will have to find small 15A fuse after al. Or maybe use smaller but slowest, slower than T, I think they are marked "H"?

[ben7]

Re: Enermax Liberty ELT500AWT fails to turn on

Just as an additional information. I got this PSU here. Seems CEC's caps lifetime is just ending worldwide This is 2th PSU with half of the caps bloated and several have been here already.

This one still turns on, but +5 V SB is only 3 V and wheezes.

As for the fuse, I will check mine in 5 minutes.

ADD// So. I have to admit you have been right. This is insane but there is 15A fuse. I discovered that in this version OS NO BLOODY THERMISTOR. Mine 400W version has one. Here is spark gap instead. I don't really like it…seems you will have to find small 15A fuse after al. Or maybe use smaller but slowest, slower than T, I think they are marked "H"?

Thats crazy, microwaves use those size fuses! :P

Get a donor NTC which is large enough, and put it in. Then just use a 5~6.3A slow blow fuse.

[Behemot]

Re: Enermax Liberty ELT500AWT fails to turn on

I am afraid there is not place where to squeeze it, really. Pads are small and when one component end, the other starts half a milimeter next to it.

Maybe DomRK would go for it but I am not doing any ghetto mods in this PSU. It is not mine, I am only replacing bad caps, otherwise it is working fine and most likely will work fine for another 5+ years after recap.

[Andreapl]

Re: Enermax Liberty ELT500AWT fails to turn on

Sorry for the digging... did you find out why the cracking sound ?
Mine does the same, no fan ...

Very intresting.

Today I have put eveything back in the PSU, and soldered it all back up.
And would you guess it, the dam thing is working again.

Just tested the voltages from the psu output and I get the following.

+5.0Vdc = +5.03V.
-5.0Vdc = NA.
+12.0Vdc = +12.78V.
-12.0Vdc = -12.13V.
+3.3Vdc = +3.43V.
+5.0Vsb = +5.20V.

ATX PSU voltage details taken Wiki
+5.0Vdc [+/-5%] (+4.75V to +5.25V).
-5.0Vdc [+/-10%] (-4.50V to -5.50V).
+12.0Vdc [+/-5%] (+11.40V to +12.60V).
-12.0Vdc [+/-10%] (-10.8V to -13.2V).
+3.3Vdc [+/-5%] (+3.135V to +3.465V).
+5.0Vsb [+/-5%] (+4.75V to +5.25V).

Also eveytime that this PSU it brought out of standby into full power, there is a crack sound coming from the PSU.

Once the PSU is running there are no strange noises coming from it.

[ChaosLegionnaire]

Re: Enermax Liberty ELT500AWT fails to turn on

yea just to clarify, i also have this unit and afaik, the liberty dxx series seem to use some kind of a relay for the automatic ac voltage detection or sumthing. so when powered on, the unit will make a clack, crack or tick sound when powering up. this is normal. the superflower leadex series also uses a relay and makes a similar sound when powering up.