Conflicting info on PSU replacment

GroverXpup · 12-21-2007, 09:32 PM

Hi again all. I've decided that I need to upgrade my PSU because of probs I've been having with my compy as of late (these probs are described in another thread, along with temps/voltages, etc.) NOW my problem is this. As you can see in my specs, my compy is almost 5 years old- it's an HP Pavilion 775e CTO (Configure to Order). It has served my well and has really given me no major probs to speak of until now. If all it needs is $75 PSU upgrade, I'm willing to stick with this tried and true compy and not look to replace it unless I have to, you know? I've read EVERYTHING I could find on PSUs and now have more questions than answers. Here goes:

Can you upgrade a PSU on an older machine to anything you want or is there a limit because it's older? The HP tech said that I can upgrade, but not past 400w (and he tried to sell me some "secret" PSU that is very rare and is the only one he could recommend for my compy). It's weird because in all that I've read, no one ever mentions this or how to calculate how much PS is too much! I've calculated my estimated wattage according to my components and I think that 400w should be fine, but is it possible to go higher if I wanted? Am I entitled to "overkill" if I want or will it hurt/not run my system??!!

I've also read that HP sometimes had an extra connector called a Video Power Connector (or something to that effect) that seems to be in my specs. I'm a bit confused about what this is- does that mean I can't get a standard ATX PSU?

And lastly, the HP guy said that all I had to worry about was that the new PSU didn't go over 400w and that it was ATX compatible, but on this forum and others, it talks about calculating how much wattage each component uses in regards to specific rails. So does this mean that I can't just go out and get a PSU that fits (physically) and has the right connections? I have to look up which hardware components use what voltage and on what rail? CRIPES. No one else seems to have all these questions, it seems like they just go to NewEgg and order one up! Am I making this too hard (I do tend to do that)?

Any help or input will be much appreciated...thanks!

PS Specs for Mobo, etc. is under my username.

**Doby** · 12-21-2007, 09:58 PM

You cannot overpower your computer, in fact if you want "overkill" you could put a 1000W psu in it and it won't hurt it providing it would fit the case and have all necassary connections.

However and what I think the HP tech was getting at is you will have trouble finding a psu that is bigger than 400W to fit in your case and thats why he is recommending not to go over that.

The tech is also correct in that some HP systems need a extra psu connection to power the video and this connection is not avalible on a atx psu so a atx psu may not work on your HP forcing you to use a hp psu.

I can't right now its late but will look into this further, but I can tell you this don't buy a psu from HP, you can get their replacement psu's or upgraded ones for half the price. I'll point you in that direction later if we determine that a atx won't wrk

is that a video card you have or are you using onboard?

Could you post a link to your other thread?

GroverXpup · 12-21-2007, 10:17 PM

Thanks for the fast reply! It's a video card and the link to the other thread is:

Random PC Shutdown (no reboot)

**TheMatt** · 12-21-2007, 10:18 PM

The only compatibility issues with older computers come with computers that used devices on the ISA bus. ISA cards need -5V to operate which is no longer included in modern power supplies (it was removed in ATX revision 1.2 in January of 2002).

**Doby** · 12-22-2007, 06:22 PM

Ok here is what I recommend but before purchase you must measure inside your case to make sure it will fit

http://www.newegg.com/Product/Produc...82E16817371006

The dimensions are here

http://www.antec.com/us/productDetails.php?ProdID=27430

I am almost sure that it won't fit but check anyway, watch there is enough room between the back of the cd drive and the psu.

If it don't fit I will find you one that does but it will be bestec or something similar and not near as good but 400w, as with most hp's you just have to live with it

**TheMatt** · 12-22-2007, 06:34 PM

That PSU is the standard ATX 140mm depth so it should fit unless the HP came with one of the "midget" power supplies that was just less deep. I remember we had one of those in the shop that we had to do a PSU replacement on and we did manage to get a standard ATX power supply fitted in there. As Doby said, the major issue will be the space between the rear of the optical drive(s) and the power supply.

12-21-2007, 09:32 PM	#1 (permalink)
GroverXpup Registered User Join Date: Dec 2007 Location: Florida Posts: 18 OS: Windows XP Home SP2 My System	Conflicting info on PSU replacment Hi again all. I've decided that I need to upgrade my PSU because of probs I've been having with my compy as of late (these probs are described in another thread, along with temps/voltages, etc.) NOW my problem is this. As you can see in my specs, my compy is almost 5 years old- it's an HP Pavilion 775e CTO (Configure to Order). It has served my well and has really given me no major probs to speak of until now. If all it needs is $75 PSU upgrade, I'm willing to stick with this tried and true compy and not look to replace it unless I have to, you know? I've read EVERYTHING I could find on PSUs and now have more questions than answers. Here goes: Can you upgrade a PSU on an older machine to anything you want or is there a limit because it's older? The HP tech said that I can upgrade, but not past 400w (and he tried to sell me some "secret" PSU that is very rare and is the only one he could recommend for my compy). It's weird because in all that I've read, no one ever mentions this or how to calculate how much PS is too much! I've calculated my estimated wattage according to my components and I think that 400w should be fine, but is it possible to go higher if I wanted? Am I entitled to "overkill" if I want or will it hurt/not run my system??!! I've also read that HP sometimes had an extra connector called a Video Power Connector (or something to that effect) that seems to be in my specs. I'm a bit confused about what this is- does that mean I can't get a standard ATX PSU? And lastly, the HP guy said that all I had to worry about was that the new PSU didn't go over 400w and that it was ATX compatible, but on this forum and others, it talks about calculating how much wattage each component uses in regards to specific rails. So does this mean that I can't just go out and get a PSU that fits (physically) and has the right connections? I have to look up which hardware components use what voltage and on what rail? CRIPES. No one else seems to have all these questions, it seems like they just go to NewEgg and order one up! Am I making this too hard (I do tend to do that)? Any help or input will be much appreciated...thanks! PS Specs for Mobo, etc. is under my username.

12-21-2007, 09:58 PM	#2 (permalink)
Doby Moderator Hardware Team Join Date: Jan 2006 Location: Central PA (USA) Posts: 7,150 OS: XP sp2/ Vista	Re: Conflicting info on PSU replacment You cannot overpower your computer, in fact if you want "overkill" you could put a 1000W psu in it and it won't hurt it providing it would fit the case and have all necassary connections. However and what I think the HP tech was getting at is you will have trouble finding a psu that is bigger than 400W to fit in your case and thats why he is recommending not to go over that. The tech is also correct in that some HP systems need a extra psu connection to power the video and this connection is not avalible on a atx psu so a atx psu may not work on your HP forcing you to use a hp psu. I can't right now its late but will look into this further, but I can tell you this don't buy a psu from HP, you can get their replacement psu's or upgraded ones for half the price. I'll point you in that direction later if we determine that a atx won't wrk is that a video card you have or are you using onboard? Could you post a link to your other thread? __________________ Would you like to help TSF fight cancer and other diseases??? JOIN TEAM TSF

12-21-2007, 10:17 PM	#3 (permalink)
GroverXpup Registered User Join Date: Dec 2007 Location: Florida Posts: 18 OS: Windows XP Home SP2 My System	Re: Conflicting info on PSU replacment Thanks for the fast reply! It's a video card and the link to the other thread is: Random PC Shutdown (no reboot)

12-21-2007, 10:18 PM	#4 (permalink)
TheMatt Moderator, Hardware Team Join Date: May 2006 Location: Boston Posts: 13,695 OS: Win 3.1, 98, NT 4.0, XP Debian 4.0, Kubuntu 6.06 My System Blog Entries: 3	Re: Conflicting info on PSU replacment The only compatibility issues with older computers come with computers that used devices on the ISA bus. ISA cards need -5V to operate which is no longer included in modern power supplies (it was removed in ATX revision 1.2 in January of 2002). __________________ - Matt M - KB1OSC - Folding@Home 85015 If TSF has helped you, please consider donating. If I have stopped responding to a thread, feel free to send me a PM with a link to the thread. It is advisable to subscribe to threads so you will receive updates when replies are posted. You can subscribe to threads from the "Thread Tools" Menu. »Memtest86 »Prime95 »UBCD »SpeedFan »NHC Personal »Everest »Sandra »PC Wizard »RivaTuner »ATi Tool Click here for Useful Articles and Guides

12-22-2007, 06:22 PM	#5 (permalink)
Doby Moderator Hardware Team Join Date: Jan 2006 Location: Central PA (USA) Posts: 7,150 OS: XP sp2/ Vista	Re: Conflicting info on PSU replacment Ok here is what I recommend but before purchase you must measure inside your case to make sure it will fit http://www.newegg.com/Product/Produc...82E16817371006 The dimensions are here http://www.antec.com/us/productDetails.php?ProdID=27430 I am almost sure that it won't fit but check anyway, watch there is enough room between the back of the cd drive and the psu. If it don't fit I will find you one that does but it will be bestec or something similar and not near as good but 400w, as with most hp's you just have to live with it __________________ Would you like to help TSF fight cancer and other diseases??? JOIN TEAM TSF

12-22-2007, 06:34 PM	#6 (permalink)
TheMatt Moderator, Hardware Team Join Date: May 2006 Location: Boston Posts: 13,695 OS: Win 3.1, 98, NT 4.0, XP Debian 4.0, Kubuntu 6.06 My System Blog Entries: 3	Re: Conflicting info on PSU replacment That PSU is the standard ATX 140mm depth so it should fit unless the HP came with one of the "midget" power supplies that was just less deep. I remember we had one of those in the shop that we had to do a PSU replacement on and we did manage to get a standard ATX power supply fitted in there. As Doby said, the major issue will be the space between the rear of the optical drive(s) and the power supply. __________________ - Matt M - KB1OSC - Folding@Home 85015 If TSF has helped you, please consider donating. If I have stopped responding to a thread, feel free to send me a PM with a link to the thread. It is advisable to subscribe to threads so you will receive updates when replies are posted. You can subscribe to threads from the "Thread Tools" Menu. »Memtest86 »Prime95 »UBCD »SpeedFan »NHC Personal »Everest »Sandra »PC Wizard »RivaTuner »ATi Tool Click here for Useful Articles and Guides