Advice: replacement PSU

Thcube

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Dec 22, 2008
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Hi,

I'm a hardware novice looking for some advice. I have an old HP Pavilion that I suspect has a PSU fault. When trying to boot up the pc, the PSU LED flashes continuously but the pc wont boot up. If I leave it for 5 mins, flashing stops and I can boot up ok. Removed all the connections and PSU LED is constant. Reconnected everything and LED is constant until 20-pin motherboard connection is added. HP website suggests that this means it is not a PSU fault. However, a number of forums report similar issues and state that a new PSU fixes the problem.

It currently has Bestec ATX-250-12Z Rev C (PSU) and an MS-6577 Ver 4.1 (motherboard). I've since added an additional 512 mb RAM, secondary hard-disk, and USB-devices (printer, speakers,graphics tablet).

I'm prepared to try a new PSU but this is where my lack of knowledge kicks in!

I've trawled the web and belive that the Bestec is a standard PSU i.e. no HP specific connectors. One question though, it currently has a single 8cm fan, whereas a lot of new PSUs either have 2 fans or a 12cm fan. Is this a problem?

I'm considering replacing with the PC Power & Cooling Silencer 500W EPS12V,
largely because it is available locally, single 8cm fan, same size. All output amps exceed those of the Bestec, with the exception of the +5v which is 24a compared with 25a on the Bestec. Does this matter?

Is the PC P&C over the top? Is it compatible with the motherboard? Anything else I should have thought about? Any other suggestions regarding PSU choice?

Thanks for taking the time to read this far. Any advice would be much appreciated.

K


 

major53

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Sep 19, 2007
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Thcube the 500 watt is a bit of a over kill for that pc.how much are you going to pay for it ,and also I believe a 380 or 400 watt would be ok.

PC Power & Cooling make some of the best psu on the market.

just don't get a psu with the Efficiency rate under 80% and you should be ok.

PC Power & Cooling,corsair,ocz ,thermaltake antec all are good psu.

and most newer psu the fans are going to be bigger.

also it would help if you list all the parts in your pc----video,ram,sound card etc.

hope this helps you out.
 

Thcube

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Dec 22, 2008
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Thanks for the reply, here's the additional info:

nvidia geForceFX 5200
128mb video memroy
Intel celeron 2.8ghz
756mb Ram (DDR-SDRam)
Integrated Sound Card

PC Power & Cooling Silencer 500W EPS12V - on offer at £40

Does it matter if the new PSU has a larger fan (12cm) or indeed 2 fans?

Thanks again,
K
 

major53

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Thcube I'm guessing 40 would equal $55.00 usa dollar.

and as far as the 120 fan and 2 -80mm,I will always go with the 120s because they are quieter and will always push more air at lower rpm.better bang for the bucks mate.

I'm also guessing that the original 250 was a antec,so how much would a pc power & cooling 380 or 430 etc cost at the store you are buying at.


the pc power & cooling 500 is a good psu,and I believe in never skimping on the psu because it runs every thing in the pc,and the price on it is pretty good,also if you go with say a better video the 500 should be ok.
 

kenzz0

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Your problem is NOT the PSU, you might have a faulty mainboard ( most likely ) or a additional PCI / PCIe card. Anyway it might be a VERY good idea to replace the PSU as well as I know them very well and they are CRAP quality.
 

doomsdaydave11

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I remember a while back there was a guy who had a similar problem, where he would turn the computer on, and it would just sit there for a good while until it finally decided to post. It did turn out that it was the PSU, and after he got a replacement it worked flawlessly.

I suggest borrowing a PSU from a friend or another computer, and testing this one out before you get a new hardware component, just in case you find it it is a different piece of hardware.
 

kenzz0

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" Removed all the connections and PSU LED is constant. Reconnected everything and LED is constant until 20-pin motherboard connection is added. " - this is pointing the fault to a different part. The PSU voltage regulator is getting " shorted " by something on mainboard - maybe bad electrolytic capacitors ? Borrowing a standard PSU is a good idea in case you want to rule the PSU out.
 

Thcube

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Dec 22, 2008
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Thanks for the advice so far.

I haven't been able to get hold of a spare PSU over the holiday period to try and test whether it is a PSU problem or not. The problem still exists that if I switch off the mains supply overnight, it takes an increasing amount of time before the LED flashing stops and the pc can be booted (30-45 minutes). However, I have now found that if I turn off my pc, but don't disconnect from the mains (i.e. leave mains plug connected and switched on) the pc will boot first time. Does this provide more evidence that the PSU is faulty?

Thanks again,
K
 

major53

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THCUBE However, I have now found that if I turn off my pc, but don't disconnect from the mains (i.e. leave mains plug connected and switched on) the pc will boot first time. Does this provide more evidence that the PSU is faulty?

don't really understand what you saying here.if you leave the power cord plugged into the power supply and the switch on the power supply to on all the time.it powers up correctly . this is the way it should be done. and it should power up correctly.