Screaming PSU fan

ishiii

ok guys
My 30 doller 350watt PSU is screaming mad.
The bottom fan has started to squeal.

Can I just open the PSU and take that bad boy out??

I know one must be careful inside a PSU.

Will taken this fan out hurt anything? Other then air being sucked from the CPU?

Advice, suggestions, and comments are all welcome.
Thanks

Thrax

Disconnect it for 6 hours, crack it open and replace it.

TheLostSwede

I have modded both my PSU's with success that way.
The 412 only have one fan defaukt but i drilled a 90mm hole in the case for it and added a 92mm fan at 7V. I also replaced the screaming default fan at the back of the psu to a much quieter fan. The result is better cooling and less noise. As long as you drain the power from the psu with the powerswitch at the back, you are ok. To test the noise from the new/changed fans, start the psu when it is out of the rest of the system by hot-wiring it.

Use a paperclip and connect the green wire to any of the black wires in the atx connector. Then just flip the switch at the back of the psu to start it.

keto

For an additional safety margin, you could wear leather gloves and rubber boots. Just don't let anyone get pictures of you near sheep dressed like that.

Straight_Man

Actually, Neoprene gloves, thick ones, would be best. Basicly, PSUs, if the caps are fully discharged, are fairly safe to work on if you are safe with electricity and protect yourself. worst problem will come if you misconnect fan, but most use a 2-wire connect so a case fan will work for replacement, and BALL-BEARINGS let a fan adjust some to more solid things in front or back of it. Sleeve bearing fans will wear out, and then squeal as the bearings give out. I use overnight as a good safe discharge time, with case earthed(connected to a ground line only). THEN any charge will be minor until you plug the thing in with new fan connected. Typically, on a fan with a 2-wire connect, RED is 12 volts into fan, black is ground (in this case return, which is often bonded to ground for safety in the overall circuit). One of the best ways to limit damage is to rig an extension cord that will cut when ground is compromised, and a ground fault interrupt (gfi) outlet in a case to plug a PSU you are testing will chop quite fast if you misconnect things so bad that you would fry the PSU, probably before the slower acting fuse in the PSU will chop power itself. Same extension cord with GFI outlet rig will chop if you plug into a bad wall outlet or if the PSU is badly miswired and the fuse is intact in PSU.

Just as with chemical burns, electrical burns need some time to act, and GFIs were intended to protect by chopping fast. give yourself a good safety cutout if you want to do more than just replace a fan, but most PSUs now have keyed fan connectors, and color codes for what eqach color means what are inside most real good PSUs or on label outside.

One thing, if you use good foot protection and use the one hand rule you can get out of most extreme electrical messes by preventing them. NEITHER hand should ever grab case, one hand should never be touching case or even within an inch or three of it at any one time- other hand can work, and you can switch hands if you want so long as boht are not ever in contact with or within three-5 inches of case or anything solid conductor at any one time. Vibram soles on shoes are decent insulators also, work boots are good as first line of foot protection defense as they are often non-conductive soles or minimally conductive soles at least in US. FRIE boots are, however,a no-no, they are made to dump so much heat that they had to be uilt with things that do conduct electricty in large amperage amounts, and it is amps that kill more often than just volts. CAPS store lots of amps, and are slowest to drain. Use back of hand to test if case is charged, if you have the other things in place that I have mentioned, electric charge will cause your hand to leap away and not tighten its grip that way.


One other thing-- never work on a PSU that is on a metal surface, the whole surface could get charged. Some folks have used nice thick (an inch or more) dry cutting boards made of cured wood to set PSUs on where they have metal surfaces as only work surface, but avoid that if you can at all as wood can burn when exposed to large amounts of amperage or wattage for a long time. Tempered GLASS cutting boards will work also as insulators, but things slide on them usually.

SIDE NOTE: Monitors and TVs are much more dangerous in parts to work on than a PSU, as monitor gun can need up to 50,000 AMPS to work right on a big TV or monitor, and the CAPS used are designed to retain lots of amps for along time even when unplugged.

John-- who was warned about fire boots in firemman training, and taught the one-hand rule first things by folks who repaired TVs, computers, VCRs, and other electronic things for decades before teaching him the basics. The neoprene thing, well, the fire trainer brought in a professional electrical company lineman who worked on the high voltage lines to teach electricaly safety, and showed videos of linemen working to illustrate what safety rules they followed. And we took apart electrical accidents to see what went wrong also.

TheLostSwede

Just tried to hot-wire my 412..no dice. No matter what i did. There must be something else on this Antec 412 that controls the power-on procedure.

Geeky1

Mackanz, short the pwr_good (grey? Check pc power & cooling's site for the ATX layout, because I don't remember which wire/color is the pwr_good lead), to +5v and then try the paper clip trick.

ishiii, just taking out the bottom fan may very well hurt something, yes. Your PS may need that fan to keep it cool enough to allow it to deliver the amount of power your system requires. I assume it's a 92mm fan, right?

If so, pick up a Sunon KD1209PTB2 fan, preferably a 2-wire one so you don't have to deal with the tach lead, but it's not that big of a deal.

Also pick up a Sunon KD1208PTB2 fan to replace the fan on the back of the PS (if you're replacing one, you might as well replace the other). Again, a 2-wire fan would be preferable, but is not necessary.

And while you do need to be careful inside a PS, I have never, ever, EVER shocked myself while working on one. Oh, wait... there was one time where I was poking around under the cover of a Dell PS while the computer was on. That's the only time I have ever been shocked. I have never had a problem with working on PSes that were off at the time, but YMMV.

TheLostSwede

Yup, paper clip (or similar) between grey and black (ground). Fans just spin a few rounds when i flip the switch but the psu doesn't output anything.

When you did this hot-wiring, did you put in the clip first, then powered on? Or did you start the thing with the clip if you know what i mean?

MediaMan

Thrax is correct. Unplug the PSU for half a day to allow the capacitors to drain of any stored electrical power.

Yes you can pull the fans and it is very easy to replace a fan. They are usually 80mm. fans and simply plug into the PCB of the heatsink.

In either case a store bought 80mm. fan will have a 3 pin MOLEX connector and the PSU fan will most likely have a different 2 pin connection.

If this is the case then snip the wire on the PSU fan leaving at least 2 - 3 inches of wire from the 2 pin molex. Snip the store bought fan wire then solder the black wires together and the red power leads together. You many end up with a spare yellow wire but that is not necessary to hook up. Remember to use electrical tape to wrap the wires or better yet...heatshrink tubing.

Look on the side of the fan boxes for the arrows indicating flow direction. On a two fan PSU the bottom fan usually blows INTO the PSU and OUT the backend.

If the fan has been directly soldered to the PSU PCB then just snip the wires leaving enough to work with ...the more the better.


If you do not want to go that far then you may try blowing out the PSU fan itself right in the core. There is a label on the fan core spindle that can be removed and then you can put the very tiniest of machine oil on the exposed spindle. That may quiet the fan for a while.

Hope this helps.

Geeky1

Mackanz, I'm not sure what you mean. The Antec will NOT start unless you short the power_good lead to +5v in addition to the normal ps_on --> ground connection.

You need to short 2 pairs of wires to get the Antec to work. Technically, you should need to do this to ALL ATX power supplies, but many of them don't seem to follow the ATX standard.

ishiii

Wow guys, thanks for all the info.

I finished this morning. I just took the old screaming 80mm out. I do not have an extra fan to put in its place. I will go to the "computer market" this weekend and get one thou.
It does have a two pin connector inside the psu, so ill just snip and rewire, no soder thou. Im not going to buy 220V tools.

MediaMan

You are most welcome. Securely and tightly wrapping each wire individually will be ok.

Straight_Man

There are three ways out of that:

one is to splice the wire strands, after sliding a piece of heat shrink tube over the longer part of the wire.

Second is to wrap the wires around each other and use low temp and high in lead "cold solder" wrapped around, then heat solder with a small butane torch or abig adjustable lighter-- pass QUICKLY over solder wrap, turn wire, repeat. Do this with the fan out of the PSU and with the wires on a piece of wood you do not mind charred places in. Then wrap with electrical tape, or first slip a piece of heat shrink tube on. Acigarette lighter, Zippo type, will heat it plenty hot, and the trick is to use one about 3X as long as you think will cover the wrapped wires, and not heat the part over the insulation as much as the part over the soldered joint.

Yes, wrapping will work, but not provide strain relief. The joint will come apart easier with electrical tape than with a wrap plus solder or even super glue if you wrap the wires around each other real tight and use a tib of super glue to hold together. I still remember not knowing how to milspec solder and having a pesky problem: The antenna for an old Walkie-talkie had come apart, been broken in half running into a tree branch, and had to be replaced. At the time, I was not confident to resolder the antenna ground, so danged if I did not carefully superglue it onto the ground mount point. Walkie talkie worked, but I had one heck of a time with glue on fingers, so next time I did that I wore throw-away Latex gloves until I found my skin reacted minorly to Latex. Now I use throw-awy Nitrile gloves, and tack tiny bits of super glue for joint reinforcement if do not have a butane mini-torch, fine solder, solder gun, or those kinds of fixings around. super glue GEL makes best tack, it does not work into the standed wrap as much. If you do not have any of those things available, a tiny bit of JB Weld can hold a joint togetehr, but the classic butt connectors also work for this, or small thin aluminum wrapped to overlap and then crimped down tight, whole covered with electrical tape.

One other trick, if you can find something that probably will be called Liquid Electrical Tape, and you wrap wires tight (hint, cut extra long for wrap, use needlenose pliers or forceps to make wrap very tight, use flush cutting pliers to snip extras), a couple to three layers of that will form a bond and an electrical di-electric flow barrier with the application of a dauber as well as corrosion protection. For a less than 5 Watt draw you need more taking apart protection than electrical insulation for an adhoc joint.

If you know a jeweler, or tech in army who is electronic tech, they could solder with solder that would suffice in three minutes flat. If you have a soldering iron, the same voltage adapter that lets an american shaver work would let a 110V soldering iron of 30-40 W work fine, also ( and that is all you need unless you are forced to use silver bearing solder).

Sounds like controlled bailing wire and duct tape time (IE condition controlled improvising).... All else fails, wrap tight and tape, with tape run an inch (2.5 cm)down onto wire for every 1/4 inch (6.25 mm) of join. That is how grandpa did it when he had no solder pot and bunson burner to heat it, or propane or butane torch to heat it on a stand-- he was an electrical contractor, and this is mostly just an electrical connect.

Oh, if you have to buy used, here is a quick test: use an air can or output for a diver's air tank to spin fan, and if it screams or whistles a lot try another fan. Bearings go first, and higher speed betrays bad bearings or dry bearings. If fan wobbles a lot, set it to one side, and see if can find one that does not, the first is probably a worn sleeve and needle bearing or a single ball and sleeve fan with wear.

John.

ishiii

Thanks again guys.
Ageek it will be a new fan, but they are super low quality crap fans. Id guess 20vfm, for 3 bucks. (Ill take some pics of the "computer market" you will all get a kick out of it.)

As far as heat shrink goes, that not gonna happen over here. No one speaks english and there is no homedepot, revy canadian tire stores here. But i will do my best with some super glue and electrical tape.