Optiplex 780 power supply

[CDart97]

I recently bought an Optiplex 780 SFF PC and put in a Q8300 and a GT 1030 GPU, as my research suggested it wouldn't be a problem-  it's a 235w PSU, the CPU wattage is the same as the previous generation Core 2 Duo it originally had and the GT 1030 is the ultra low profile version with very low power draw. I ran a bunch of stress tests and never had any suggestion that it would be a problem, everything was running fine. 

 

Couple of days ago it shut down randomly and wouldn't come back on, left overnight and plugged back in and it worked fine. Did a bit more testing and it seemed to be okay, and I just went to turn the PC back on and the power supply popped and died straight away.

 

Is this because it's a 10+ year old supply which has degraded through constant use for 10 years as a school computer and it just couldn't take the heat any more? I'm looking for a replacement but now concerned that even a new 235w won't be enough, although people don't generally seem to get the same problem as this? Will I be safe to just replace with the same again?

[-rascal-]

8 minutes ago, Dartman5 said:

I recently bought an old 780 SFF PC for cheap and put in a Q8300 and a GT 1030 GPU, as my research suggested it wouldn't be a problem-  it's a 235w PSU, the CPU wattage is the same as the previous generation Core 2 Duo it originally had and the GT 1030 is the ultra low profile version with very low power draw. I ran a bunch of stress tests and never had any suggestion that it would be a problem, everything was running fine. The PSU would get fairly hot but I thought this was because of its small size and a few other people had the same thing.

 

Couple of days ago it shut down randomly and wouldn't come back on, left overnight and plugged back in and it worked fine. Did a bit more testing and it seemed to be okay, and I just went to turn the PC back on and the power supply popped and died straight away.

 

Is this because it's a 10+ year old supply which has degraded through constant use for 10 years as a school computer and it just couldn't take the heat any more? I'm looking for a replacement but now concerned that even a new 235w won't be enough, although people don't generally seem to get the same problem as this? Will I be safe to just replace with the same again?

 

It's definitely the age of the PSU, and the 24/7 on-time for 10+ years.

Plus, it probably wasn't a top quality PSU to start with, as with typical consumer Acer / HP / eMachines computers.

 

~250W should be plenty for that system configuration.

[homeap5]

It is PSU... or not.

These motherboards are really bad. If your GPU gets power from PCI-E (and I doubt that your PSU has GPU power connector) then it may be also fried motherboard.

 

[CDart97]

I've taken the PSU apart and the PCB inside it smells burnt.. fairly confident it's just that but of course not sure whether these OEMs would have protection from surges etc... I guess it seems realistic that continually being on in a school for God knows how long is going to wear it out significantly over time

[jaslion]

29 minutes ago, Dartman5 said:

I recently bought an old 780 SFF PC for cheap and put in a Q8300 and a GT 1030 GPU, as my research suggested it wouldn't be a problem-  it's a 235w PSU, the CPU wattage is the same as the previous generation Core 2 Duo it originally had and the GT 1030 is the ultra low profile version with very low power draw. I ran a bunch of stress tests and never had any suggestion that it would be a problem, everything was running fine. The PSU would get fairly hot but I thought this was because of its small size and a few other people had the same thing.

 

Couple of days ago it shut down randomly and wouldn't come back on, left overnight and plugged back in and it worked fine. Did a bit more testing and it seemed to be okay, and I just went to turn the PC back on and the power supply popped and died straight away.

 

Is this because it's a 10+ year old supply which has degraded through constant use for 10 years as a school computer and it just couldn't take the heat any more? I'm looking for a replacement but now concerned that even a new 235w won't be enough, although people don't generally seem to get the same problem as this? Will I be safe to just replace with the same again?

I would at this point just scrap the system. No saying what the dead psu might have taken with it. These machines go around for 50$ or less usually so not really worth getting a used psu that is half it's value when you could get a much better core I series unit for around 60-70$

[jaslion]

Just now, Dartman5 said:

I've taken the PSU apart and the PCB inside it smells burnt.. fairly confident it's just that but of course not sure whether these OEMs would have protection from surges etc... I guess it seems realistic that continually being on in a school for God knows how long is going to wear it out significantly over time

The components degrade over time. A lot faster when in use. 10+ years of general use is a lot for a psu that already has low headroom.

[Slayer3032]

OEM prebuilts are notorious for having garbage power supplies that aren't anywhere near stout enough to supply what they're labeled to do. The computer is honestly lucky it didn't already fail. Not only that but they're almost always the most bottom of the barrel junk that they could get their hands on in some proprietary format that makes it so you just pop the components out of the board and toss the case, psu and motherboard in the trash where they belong. If there's a corner to cut, expect it to be completely snapped off as shallow as possible with low end OEM stuff.

 

LGA775 really isn't bad, I have a build kicking around with my old Q6600 and a $20 60gb ssd that somehow manages to boot faster than anything I've ever seen on a sata drive or even a 6600k/nvme build that I setup. If you can get your hands on a decent motherboard, there's LGA771 modding and all sorts of fun stuff you can do along with plenty of overclocking or potentially underclocking/undervolting as well.

 

I might recommend LGA1156 if you're looking for something a little newer in a dirt cheap SFF prebuilt, most of those should support the Lynnfield Xeons like the X3470 if they support a i7-870. I'm sure people would be eager to throw away the old i3's and Pentiums on that platform. For not much more, you can find all of the newer platforms as well which generally all have far better performance. You can usually find a pretty good Haswell or Skylake SFF under $200.

 

If you're actually looking to play games on it and not just have a nice little HTPC or something, look for a "MT" or mini tower and specifically look for something that uses a standard 24pin power on the motherboard. If it has a standard 24 pin, you can swap in a standard replacement psu and use a proper graphics card. I'm sure here in a few months GTX 970's and other similar performance gpus are going to become even cheaper used so you could probably get a pretty good 1080p60 build going with a $50~ gpu.

[steelo]

1 hour ago, Dartman5 said:

I recently bought an old 780 SFF PC for cheap and put in a Q8300 and a GT 1030 GPU, as my research suggested it wouldn't be a problem-  it's a 235w PSU, the CPU wattage is the same as the previous generation Core 2 Duo it originally had and the GT 1030 is the ultra low profile version with very low power draw. I ran a bunch of stress tests and never had any suggestion that it would be a problem, everything was running fine. The PSU would get fairly hot but I thought this was because of its small size and a few other people had the same thing.

 

Couple of days ago it shut down randomly and wouldn't come back on, left overnight and plugged back in and it worked fine. Did a bit more testing and it seemed to be okay, and I just went to turn the PC back on and the power supply popped and died straight away.

 

Is this because it's a 10+ year old supply which has degraded through constant use for 10 years as a school computer and it just couldn't take the heat any more? I'm looking for a replacement but now concerned that even a new 235w won't be enough, although people don't generally seem to get the same problem as this? Will I be safe to just replace with the same again?

It's probably the PSU. However, even if you do discover that the PSU is bad, it may have taken your MB or other components out with it. Do you by chance have another PSU to try? If not, you could always order one and if you find the MB is also bad, save it for your next build.