PSU questions

[jwhiz]

Hi, I bought an old 'mystery machine' PC a few months ago, and while it functions well, the fan in the 300 W PSU seems to be failing (makes a racket when starting after at least 20 minutes off, then fades after about 10 minutes to a dull roar. When you prod the case of the PSU, the fan pitch changes).
I have another 300 W PSU, so for a change I'd thought I'd ask questions, and THEN 'experiment':

#1 - what are compatibility issues? PSU now in box is a Powerlink LPT2-20 300 W ATX, with 22A on 3.3V, 30 A on +5 V and 14A on+12 V (also 0.3 on -5 and 0.8 on -12). The mobo connector is a 20 pin (i have contacted the mobo maker of this...thing, a K7SOM+, and their helpful resonse was that "most power supplies over 350 W should work". Uh huh.)
The PSU I was wondering about swapping in is from an older PC with a dud mobo, as far as I remember the PSU was fine, here are it's specs: Star Tek (really ) AP-350X 300 W, with 20 and 4 pin mobo connectors, with 28A on 3.3, 30A on +5, and 15A on +12 (same -5/-12). Is the loose 4-pin connector an issue? what about the differing amperages on the rails, should I be happy for more power or is overpushing a concern?

#2 - how might I test the 2nd PSU without hooking it all up?

I have been mooching around the internet for a few days, I have some idea of which makers to avoid if I end up buying a new unit. I plugged in some figures to an online wattage calculator, and, wow, it suggested 280W requirements...As this is a 'second' computer, I don't want to put a gob on my credit card, but i don't want to put a dud PSU in it either - I know you are in the UK, and I'm in the Dominion, but any ideas for 300W or 350W units in the sub-$100 CD range would be appreciated!

Some specs on the PC are:
mobo as noted
some kind of AMD-type CPU, 1.3GHz (I can't see a label, and box isn't running at moment!)
NVidia GeForce FX5200 (PCI) instead of onboard video (added)
onboard sound
1 GB DDR RAM (has heat spreader, max. supported)(added)
1 extra case fan (ball bearing)(added)
Maxtor 30 GB HD, Western Digital 40 GB HD (added)
onboard NIC
Win XP Pro, SP2 (on 30GB), Win 98SE (and soon, Linux) on 40 GB (I just added WD HD, it's newish from another old PC, OS only and no files, want to try running internet through that instead of Windows)

My #1 computer is an Apple PowerBook G4, my other #2 PC is an ancient (but functional) Dell desktop. O yeah, and the Palm Tungsten E2...and those other things are just PC component storehouses...

 

[Shinobi Strikes]

Hi,
To the best of knowledge you should be fine. All PSUs have to follow a standard (EG: ATX V2) and should be alright. In reply to question 2; PSU testers are cheap and easy to get from just about any electrical website. You could easily pick up a decent PSU that covers your needed wattage for far cheaper than $100. Some names to dodge like a speeding bullet - iCute, Vcool and Xpower.

You may want to get another member to check all of this before you start thinking of buying anything. Best of luck

 

[jwhiz]

cross fingers - the 'old' PSU has been running for several hours now...I remember that it seemed to run warm, and one of the few reviews I could find for the StarTech noted that too, but most seemed to like it, including that reviewer.
Top of case still feels cool, the PSU fan is pushing out much warmer air, right away, than the other PSU, maybe that just means that the PSU in there now has a fully functional fan!
I noted that StarTech actually sells replacement PSU fans, not sure I want to leap into opening up power supplies after all the lectures i got on Field Replacement Units!

 

[Abarbarian]

Hi there you can replace the fan in your psu . BUT PSU's have some dodgy elctrical commponents in them which can be LEATHAL as they retain some charge . So only try to replace the fan if you know what you are doing .
Any fan of the right size can be fitted , its worth checking out how much air the fan moves . Forr $5 to $10 its a cheap way of keeping your psu working .

http://www.bleedinedge.com/guides/psu_fan_r2/psu_fan_r2.html

There are several guides around above is one example .

Just heed the warning about the DANGERS and take care .

 

[jwhiz]

opening FRUs

Hi Aba...buh...rrnnyou, yes, I see that I can get a fan for this exact model in fact (from StarTech), I have no tools or workbench, I think the last time I did any soldering was a billion years ago, so egh.
I'd like to be able to have proper bench someday though...dunno if I'll ever work up the nerve to open up anything where capacitors are storing lethal charges though. El, oh, el.
I actually saw a tutorial some time this week from someone who was actually fixing the fans themselves (removing and lubing the blades) - at least that's something one could try without the unit buzzing with wayward energy, and fans ARE cheap. I'd post the link - but it's on my PowerBook, which is Over There.
Wow, am I lazy some days.