Power supply

guil

I posted this in building and upgrading but thinking it might be better suited here.

I think I might need a replacement PSU but can anyone tell me how to rule out anything else before I buy one? It's only a cheap Dell optiplex 390 I bought and put in more ram, a graphics card and replaced the PSU.

Right now it has 6gb ram, gtx 460 and 500w power supply. When I plug it in I get no lights other than the orange ones on the Mobo, it happened a few times before and pulling out the usb wifi dongle and joypad worked and the power button etc lit up. Now nothing is happening regardless of what I disconnect. I've tried the paperclip test and the fan comes on bit nothing when I connect it back up to the Mobo.

What would be an ideal replacement if that is indeed what I need? I need 2 6 pin pci-e connectors or 1 pci-e and I could use the money adapter I have and ideally as cheap as possible. I've paid very little for everything and want to keep it that way until I build a decent computer.

gctest50

Some dells have the same connector but different pinout - kills it if you replace with normal psu

guil

I've been using it since June I think, would it be something that would happen straight away or would it be happen over time?

gctest50

The ones that are different are wildly different - wouldn't even start

guil

I don't think that is the issue then because I've used it for 10 or more hours at a time playing games.

guil

This has me stumped, I tried it yesterday and turned on no problem and was on for the best part of the morning and afternoon until I turned it off. Dead as a dodo today again though. Any ideas?

smuggler.ie

Have you checked "Diagnostic LED's" for your model/year, see if you can read failure cause?

https://www.dell.com/support/article/ie/en/iebsdt1/sln284978/a-reference-guide-to-the-dell-optiplex-diagnostic-indicators?lang=en

And sub-link if this matching your case

Note: Please remember that the diagnostic LEDs only serve as an indicator of the progress through the POST process. If the system doesn't show any LED's or only a Flashing Amber Power LED, then you could be looking at a Power issue before the POST starts. If this is the case then please go to the following article for further troubleshooting:

• How to Troubleshoot a No Power Issue on your Dell Desktop

guil

Thanks for that. I've come across that before but I'm nearly certain the power supply is the problem. I put the Dell power supply back in and the test light on the back is working with everything connected except my graphics card as it doesn't have 6 pin pci-e.

I'll see how it goes for the next few weeks before I buy a power supply.

smuggler.ie

What is actual model of yours - there is like dozen of Dell Optiplex 390 sub models?
By graphics card could only guess it is Dell Optiplex 390 MT

Your GTX 460 claim min 450W system PSU
Have you many peripherals/hardware on system? Check your PSU requerements - it is better to have extra ~100W rather just match
Cheap "PoS" brand PSU's, even rated at 500W on label, might not provide.
If it comes for replacement would recommend to choose known brand

guil

How do I find the exact model? It's has a Pentium g840 cpu. I bought the graphics card on adverts and also the power supply so I kind of knew this would happen sooner or later.

smuggler.ie

Any labels on PC.
https://www.dell.com/support/article/ie/en/iebsdt1/sln298441/how-to-find-the-product-model-of-your-dell-computer?lang=en#Section_3

smuggler.ie

Do you mean you board second hand PSU on adverts?

guil

Yes i bought a second hand psu on adverts and the support assist just says optiplex 390.

smuggler.ie

OK.
So your system running fine with original PSU (255w?) and without PCI graphics.
That leaves you with faulty PSU
Once you have plan to build PC some time in the future , think of what components you plan to have, use calculator (post#9) + ~100÷200w on top of that and shop for some good quality PSU.
Most good brands do modular units so you use cables only what you need now, and when time comes you can move this unit to new build.

guil

Yes the stock PSU is around that, can't remember the exact wattage. Thanks.

TerrorFirmer

Just get a new card. The GTX460 is ancient and guzzles power for pretty low performance. Something like a €80 GT1030 2GB new would offer better performance and use a fraction of the power and work fine with the original Dell PSU.

Or else 2nd hand a GTX750Ti for about €60-70 would also be fine and offer even better performance.

If you're not playing games a €25 GT710 or simialr will be fine. I assume you're probably not with that pentium.

guil

All I play is farming simulator 17 and ets2, the Dell power supply has no extra power connections except 2 sata. This PC was just a cheap thing that was thrown together and I'm probably going to put together something half decent next year sometime so don't want to put any big money into this.

TerrorFirmer

guil wrote: »

All I play is farming simulator 17 and ets2, the Dell power supply has no extra power connections except 2 sata. This PC was just a cheap thing that was thrown together and I'm probably going to put together something half decent next year sometime so don't want to put any big money into this.

You don't need any power connectors for GTX750, GT1030, GTX750Ti, GTX1050, GTX1050Ti, etc.

You would get a GTX750Ti for about 60 2nd hand, it's faster than the GTX460 and uses about a third of the power.

Replacing a PSU for the second time just to power an ancient power hungry GPU is a waste really.

guil

Oh really? I presumed all graphics cards need their own power connector. Thanks for the info, out of those you listed which do you think would be best bang for buck or easiest to find?

guil

Got sick of trying to find something relatively close on adverts that may or may not have worked so went to PC world today and bought an Asus GT 1030. I know I could of got better bang for my buck online but I have no patience.

Thanks for all the advice.