Replacing the PSU in an old Dell pc

[moneer]

Hello ananders. I hope everyone here is having a fantastic day.
I've been trying to breathe some more life into my old dell pc. My current financial situation does not allow for me to build a new pc. To get any decent gpu, I would need a psu that has a 6 or 8-pin connector, something the current psu pre-installed does not have. It doesn't even have molex connectors...
It is a dell optiplex 755 small form factor.
Currently I have the EVGA gtx 750ti superclocked, and had to make adjustments to the case to fit it in there.

Would a tfx psu be compatible with this pc? I heard the volatages may not be compatible so the mobo might get fried. Is that true?

Should I lose all hopes of gaming on this pc?

Thanks in advance.

 

[UsandThem]

http://en.community.dell.com/support-forums/desktop/f/3514/t/19523542

 

[Mike64]

Hello ananders. I hope everyone here is having a fantastic day.
I've been trying to breathe some more life into my old dell pc. My current financial situation does not allow for me to build a new pc. To get any decent gpu, I would need a psu that has a 6 or 8-pin connector, something the current psu pre-installed does not have. It doesn't even have molex connectors...
It is a dell optiplex 755 small form factor.
Currently I have the EVGA gtx 750ti superclocked, and had to make adjustments to the case to fit it in there.

Would a tfx psu be compatible with this pc? I heard the volatages may not be compatible so the mobo might get fried. Is that true?

Should I lose all hopes of gaming on this pc?

Thanks in advance.

Fwiw, if the existing PSU has the wattage to handle the card in question and you have free SATA power cables, they make SATA -> 6/8-pin PCIE adapter cables as well as the molex ones. (I have no idea how well they work as a practical matter, but it seems worth trying before dealing with expense and hassle of replacing the PSU, especially since Dells aren't well-known for making it easy to take almost everything apart and put it back again. (And I can say from my own experience that's certainly true of my mid-sized Dell case; I imagine it's that much worse in their small form factor cases...)

 

[moneer]

http://en.community.dell.com/support-forums/desktop/f/3514/t/19523542

That's for mini tower. I have small form factor.

Fwiw, if the existing PSU has the wattage to handle the card in question and you have free SATA power cables, they make SATA -> 6/8-pin PCIE adapter cables as well as the molex ones. (I have no idea how well they work as a practical matter, but it seems worth trying before dealing with expense and hassle of replacing the PSU, especially since Dells aren't well-known for making it easy to take almost everything apart and put it back again. (And I can say from my own experience that's certainly true of my mid-sized Dell case; I imagine it's that much worse in their small form factor cases...)

I actually had to use cables from a different psu I had lying around to make a second sata power connector. I only have 2 and both are in use lol. This one is actually easy to take out. 2 screws and slide it off.

 

[UsandThem]

That's for mini tower. I have small form factor.

I didn't realize they made different form factors, but gave it the same model number.

I read through several forums, and it seems like the SFF power supply is proprietary.

https://hardforum.com/threads/optiplex-755-sff-video-card-upgrade.1739391/

http://www.tomshardware.com/forum/299280-32-dell-optiplex-upgrade

 

[Mike64]

I didn't realize they made different form factors, but gave it the same model number.

Dell (and to be fair the other big pre-built PC sellers in general) is incredibly annoying like that. Given a usually fairly broad range of case sizes factors and invariably quite a range of internal component options (not all of which will work in all cases or configurations) they sell under each model number, it's frankly anyone's guess what the hell a model number is really supposed to signify at all...

 

[Mike64]

Hello ananders. I hope everyone here is having a fantastic day.
I've been trying to breathe some more life into my old dell pc. My current financial situation does not allow for me to build a new pc. To get any decent gpu, I would need a psu that has a 6 or 8-pin connector, something the current psu pre-installed does not have. It doesn't even have molex connectors...
It is a dell optiplex 755 small form factor.
Currently I have the EVGA gtx 750ti superclocked, and had to make adjustments to the case to fit it in there.

Would a tfx psu be compatible with this pc? I heard the volatages may not be compatible so the mobo might get fried. Is that true?

Realistically, you're probably best off poring over the Dell forums with a fine-toothed comb, searching on your specific motherboard as well as the model number (and try posting there, you might get lucky and get a useful answer) given how configuration-specific Dells tend to be. (Maybe other pre-built PCs, too, but I know from experience that knowing "just" the model number and case size often isn't enough with a Dell, given how tightly they tailor their specs - presumably to cut costs - to the configuration it ships with. Usually it mostly affects things like the compatibility of different CPUs and RAM, but for all I know, it could affect the PSU specs, too...) If you don't know the mobo offhand, you'll have to search the site to figure out whether there are multiple possibilities for your model and if so, which you have, based on the PCs configuration. There's a slight chance their support site will tell you which you have based on your "service tag" but I don't think it gives that much detail as a matter of course. There's a web-based utility that can dig/figure out the tag by scanning your PC online, if you haven't previously made a note of it ...

 

[Billb2]

An option for the Optiplex 755 SSF is to remove the proprietary Dell PSU and mount a "regular" PSU out side the case. You'll need an adapter for the motherboard plug as the Dell pin out is proprietary too. I got one from Ali Express for less than $5 delivered.

 

[VeryCharBroiled]

if you enter the units Service Tag at dells website you can get a lot of useful info about that particular system.

for my optiplex 980 it comes in 3 case sizes and the mobos are slightly different for each formfactor, like 2 vs 4 sata ports, number of usb headers etc. infuriating..