Question Only original PSU seems to work?

[Elliott946]

My computer died recently, and the timing was really bad so I ran out and bought a cheap Dell from Best Buy (its fine, you can judge me. Time was just too much of an issue). Its enough to get done what I needed to do right then, and my plan was to replace the psu and graphics card with the ones I'd saved from my old computer when I had some time. Seemed easy enough.

It did not prove that easy. Among other things, the Dell's mobo had no 20/24 pin power slot, instead having a 4 and an 8. I'd heard of that before, but I'd never seen one and it confused me for a bit.

Paperclip test said my old psu was fine, so I removed and replaced everything that needed removing and replacing, plugged everything in and... nothing. With the paperclip test, my old PSU (Ultra X-Finity 600W) seemed to run just fine, but when I actually plugged it into the new computer, it did nothing. I assumed the 8 and 4 pin connections to the MOBO weren't properly telling the PSU to run, so I plugged everything plus had the paperclip inserted (maybe not the best idea in hindsight), turned it on and... nothing.

I thought maybe it was the psu afterall, so I ran out and got another psu, and had the exact same result. I tried reinstalling the original psu and it started up perfectly.

So, now I have a quandry. The psu it came with is, of course, bare-bones and wouldn't have the power to run my graphics card (Radeon 7850) if it had the pci-e connector to plug into it (which it doesn't). It doesn't even have an extra SATA connector so I can't even plug in the SSD I saved from my old computer (and I kinda need it).

Is there some reason it would only run with the original psu? Very perplexing.

Edit - I'll try to add the mobo model and a pic of the inside.

 

[Rogue Leader]

Wait..... so what exactly from this new PSU did you plug into your DELL motherboard?

In the end the 24 pin from the new PSU I'm assuming is connected to nothing. Thats your first problem. Your second problem is depending on what you did use to connect it the fact you forced a connector into a spot it shouldn't be and used a paperclip to power it up you could have damaged the motherboard. Although I believe I understand you plugged the old DELL PSU back in and it worked so you may be safe.

There are adapters out there to make aftermarket PSUs work on dells, for example

https://www.amazon.com/COMeap-Adapter-Optiplex-Precision-12-inch/dp/B06XGWRTHC

You want to look up which one works specifically with the model Dell you own before buying.

 

[Elliott946]

Wait..... so what exactly from this new PSU did you plug into your DELL motherboard?

In the end the 24 pin from the new PSU I'm assuming is connected to nothing. Thats your first problem. Your second problem is depending on what you did use to connect it the fact you forced a connector into a spot it shouldn't be and used a paperclip to power it up you could have damaged the motherboard. Although I believe I understand you plugged the old DELL PSU back in and it worked so you may be safe.

Thanks for the quick response. Yep, the 24-pin on my psu was just sitting there touching nothing but a paperclip and some electrical tape. For the rest, nothing was forced, the X-Finity had both a 4 and an 8 pin power connector and those fit just fine into the mobo, just nothing would turn on after they were plugged in. And the mobo survived the shenanigans just fine, in fact I'm typing on that computer right now.

There are adapters out there to make aftermarket PSUs work on dells, for example

https://www.amazon.com/COMeap-Adapter-Optiplex-Precision-12-inch/dp/B06XGWRTHC

You want to look up which one works specifically with the model Dell you own before buying.

Wait, does that mean regular psu's don't work on Dells just in general? That'd be unfortunate. I know cheap HP desktops sometimes have weird, proprietary connectors that make life difficult but I didn't know Dells did the same thing.

 

[Rogue Leader]

Thanks for the quick response. Yep, the 24-pin on my psu was just sitting there touching nothing but a paperclip and some electrical tape. For the rest, nothing was forced, the X-Finity had both a 4 and an 8 pin power connector and those fit just fine into the mobo, just nothing would turn on after they were plugged in. And the mobo survived the shenanigans just fine, in fact I'm typing on that computer right now.

Yeah I'd imagine the plugs may be keyed similarly that they work. Glad you didn't do any damage.

Wait, does that mean regular psu's don't work on Dells just in general? That'd be unfortunate. I know cheap HP desktops sometimes have weird, proprietary connectors that make life difficult but I didn't know Dells did the same thing.

Correct, they need this adapter. Dell has been doing the same thing on some models for quite some time now. But at least there are adapters out there.

Just Google your model Dell and "PSU adapter" and you will find what you need. Now personally I do not like using adapters for anything, but your only other option is to buy a new motherboard.

 

[Elliott946]

Yeah I'd imagine the plugs may be keyed similarly that they work. Glad you didn't do any damage.

Thanks, yeah, me too. It was one of those moments where I was so pleased I'd figured out something that I could do that I didn't stop to think if it was something I should do. Got lucky.

I'll check amazon for the adapters. Thanks again!