Do PSUs have fairly standard connections to the motherboard and drives? One of my PCs intermittently stops, with screen blank (just "no signal", not the dreaded "blue screen of death"), sometimes after a minute or so it shows the "Restart Windows" at other times it just sits with the power light on and fan running but nowt else.

Some days on switching on it does not boot, power light and fan come on, no sign of life on the HDD activity light nor screen, the DVD button works to open for load/eject.

My guess is an intermittent fault in the PSU, I'm debating if to chance getting a new PSU or alternatively a barebones PC; I don't need any drives, I have SSD and a few HDDs so don't see a need for a complete PC

I believe PSU's are all pretty much the same only the power rating changes.

Paul. Connectors depend on the age of the MB that it will Be connected to.

Look up the MB specs and it will tell you how many power connectors and how many pins per connector. Also,whether IDE or SATA  connectors  required

Then select appropriate PSU
https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2053587.m570.l2632.R-1.TR3.TRC1.A0.H0.Xcomputer+psu.TRS0&_nkw=computer+psu&_sacat=175673


You can buy PSU testers cheaply on eBay and it might be worth investing in one

https://www.ebay.co.uk/p/Digital-LCD-PC-Computer-Power-Supply-Tester-20-24-Pin-4-PSU-ATX-SATA-HDD-Testers/2218690023?iid=173023530649


Also,  heck whether the PSU fan is working / clogged with dust - it may be overheating and cutting out.

Dead fans are easily replaced, provided the PSU capacitors are well discharged! ( how do I know...)

The boot disc is an SSD,  might it be worth putting a spare HDD in it's place?  However it doesn't even display the opening page that gives access to the BIOS settings which makes me think more likely PSU; nor does it attempt boot from a Win 7 CD.  Fan works, fault can often occur at first switch  on in the morning, so unlikely to be overheating.

The PC is just over 2 years old,  AMD A10-6800K processor, 16G RAM, 256G SSD, 2Tb HDD, Gigabyte motherboard; Win 7 pro 64bit.

If the PC doesn't do the POST and you don't get beeps from the speaker, usually a PSU fault. First thing to try is reseating the power connectors.

Sorry... thread hijack...

Malc you're back from the show, then?

Expect report

Back to psu thread. Sorry! 

Quote from: Malc on February 04, 2018, 09:09:15 AM
If the PC doesn't do the POST and you don't get beeps from the speaker, usually a PSU fault. First thing to try is reseating the power connectors.

Already done that numerous times, problem is it's intermittent, sometimes goes 2 or 3 days OK then refuss to start, this morning I've redone all the checks, tried swapping SSD, reseating all connectors again, after about half hour of such twiddling it sprang into life.

I'm thinking more now towards a barebones, I've got enough drives and RAM; don't see the point of a complete PC, can probably get a higher spec for same or less money.

Could well be the PSU, but motherboard, CPU and RAM are also a possibility (normally I would expect beep codes if it was the Mbd, etc, as another poster has already mentioned, but I've had the odd case where there aren't any and it turns out not the be the PSU). Intermittent faults like this can be a right bugger to get to the bottom of!

Have you tried removing the RAM modules, making sure there's no dust in the sockets, and putting them back a different way round (i.e. not in the same sockets they came out of?) Unless all sockets are full, use the same sockets though, just make sure each module isn't in the one if came out of. Also worth checking that the CPU is properly seated, and if t's a separate graphics card pull that out, check the connector is clean and put it back in again.

I would doubt if it's a problem with any of the fans as you state that it sometimes happens when first turned on. Overheating problems don't usually occur at boot when the system is cold - they tend to lead to the system shutting down suddenly after it's been running for a while and the temperature of the CPU has had time to rise.

A switch mode PSU is full of electrolytic capacitors. If they start aging, the PSU may fail to start generating DC. If it is more than 5 or 6 years old, scrap it . You can get a new one for about £20 off Amazon. It's not worth faffing about. If the fault still occurs, at least you have eliminated one of the variables.