Antec AR300 psu, loud squeal, no power

[Sylvester]

I've read the other posts on this psu but not sure if a repair is possible, the psu emits a loud squeal when powered up but that's all, its 2004 vintage so suffers from the badcap syndrome, I've posted some pictures of the pcb, any thoughts on repair?

[Harvey]

Re: Antec AR300 psu, loud squeal, no power

My thoughts on repair:

Don't bother.

PSUs are only just worth the trouble of repairing if they basically work but have tired caps, but once the have damaged components like ZD3 - its not worth it.

[Sylvester]

Re: Antec AR300 psu, loud squeal, no power

Kinda thought that, but a replacement is expensive here in the uk.

[severach]

Re: Antec AR300 psu, loud squeal, no power

In addition to your domed caps one or both caps next to the burned diode are burned out from the heat. The squealing may be the small cap arcing. The fatal Bestec cap tick as they arc.

If the burned diode still works then you could have something testable in 4 caps. I've seen Bestec with that much discoloration on the board and diode legs and work with good caps. Since you'd rather not burn out your motherboard supply an LCD power supply tester and a ESR meter would be very helpful here. You should at least have a DMM to measure 5vsb before hooking up to a motherboard.

[ratdude747]

Re: Antec AR300 psu, loud squeal, no power

just can it. that board is just too burnt up. otherwise id replace the diode and and recap it, would be very reliable after that.

[ratdude747]

Re: Antec AR300 psu, loud squeal, no power

odd- why isnt the cap with the teapo stamp right by the diode bulged- wait- teapos will dry up! more proof that antec= over-priced box from hell.

[Newbie2]

Re: Antec AR300 psu, loud squeal, no power

That power supply doesn't look like it's worth repairing in my opinion, chuck it in the trash and go buy a new power supply.

The PCB appears to be in bad shape along with damaged components.

[ratdude747]

Re: Antec AR300 psu, loud squeal, no power

strip the fan and wire first, keep the board for recapping/soldering practice. or (wearing breathing mask, gloves, long protective clothing, and goggles) desolder everything, and sand it into a frisbee. i somtimes use dead micro atx boards for that. fun.

[ratdude747]

Re: Antec AR300 psu, loud squeal, no power

moot point: it looks like ec6 also overheated.

[linuxguru]

Re: Antec AR300 psu, loud squeal, no power

It's a Channel-Well OEM unit, which may be worth repairing, depending on the value of your time. All the Fuhjyyus have got to go, even if they look normal from outside. Then fix the dry joints by reflowing them with fresh solder. Then you can try debugging the circuit around the zener ZD3, EC6, etc.

[Per Hansson]

Re: Antec AR300 psu, loud squeal, no power

If you like to learn sure it's a good thing to try to fix, but wont be worth it time wise if you are doing it for someone

Try powering it up with the case off, I bet it's the burnt diode that is what is arching, I saw that in my nice Eizo CRT, never bothered to repair it tho, may it RIP

[Harvey]

Re: Antec AR300 psu, loud squeal, no power

Kinda thought that, but a replacement is expensive here in the uk.

Cheaper than getting replacement caps/diodes/opto isolator/mosfets/etc. that would need to be replaced to make the unit reliable, that's assuming you can guess the value of R29.

Unless you happen to have a motherboard you don't mind sacrificing in 3 months time when the part you haven't replaced fails....

[ratdude747]

Re: Antec AR300 psu, loud squeal, no power

like i said, gut it for fans and wire.

[Krankshaft]

Re: Antec AR300 psu, loud squeal, no power

Yeah if you caught this sooner (before the diode smoked) you probably would have been able to easily save it with caps.

I caught my Antec early and bought 2 more dirt cheap which I saved with a recap.

I just happened to stumble across this forum opened my PSU (which was still working) and the dreaded Fukyuus were bulging.

Oddly enough though on my servers TP 2.0 350W supply even after 4 years in my cold basement not a single one bulged. That could be because the PSU wasn't stressed or the low temperatures kept them from dying. They got replaced anyways.

If you can replace the glass diode and any other charred or fried components that test bad with a DMM and replace the Fukyuu caps it should power up. Squealing is usually a protection circuit kicking in.

If you're a first timer this will be an ambitious project.

[Krankshaft]

Re: Antec AR300 psu, loud squeal, no power

that's assuming you can guess the value of R29.

That's probably just flux.

[370forlife]

Re: Antec AR300 psu, loud squeal, no power

odd- why isnt the cap with the teapo stamp right by the diode bulged- wait- teapos will dry up! more proof that antec= over-priced box from hell.

Though that teapo probalby is dried up from the heat, teapos are fine in new power supplies. They seem "at home" in them.

[Sylvester]

Re: Antec AR300 psu, loud squeal, no power

Thanks for the comments, what's the most likely cause for the failure, the diode has obviously taken a bit of heat?

I can't quite make out the diode markings, the only numbers I can see are 474 I think, you have to look really closely at an angle to make them out.



The cap shopping list is:

10uF 50v x3 teapo

100uF 50v fuhiyuu

22uF 50v x2 fuhiyuu

1000uF 10v x2 fuhiyuu

4700uF 6.3v fuhiyuu

2200uF 10v x2 fuhiyuu

1000uF 16v fuhiyuu

330uF 25v fuhiyuu

330uF 16v fuhiyuu

470uf 16v teapo brown

3300 6.3v teapo green

[momaka]

Re: Antec AR300 psu, loud squeal, no power

Would be nice if you can get it fixed, but that depends on whether you have the time or not. If it's just for learning experience, this will do.
----
And even if you decide no to repair it, you should still keep it. There are plenty of good parts inside that you can use besides the wiring and fans (coils, x and y caps, rectifiers, bridge diode, etc.). Sometimes cheaper power supplies might need one or two of these components to make them complete.

[kc8adu]

Re: Antec AR300 psu, loud squeal, no power

look for a 1n number on that diode.likely a zener.replace it and the caps.should be ok after that.

[Sylvester]

Re: Antec AR300 psu, loud squeal, no power

I think the zener is a 1n4740, the markings are very faint but look like 4740