Pc Post Probs

My 5 yr old PC has been fine for all 5yrs, until a couple of days ago, when upon pressing the power button from cold it plain refused to boot at all, with just the usb light flicking on/off on the front, I checked everything inside inc all connections/leads/jumpers and changed the button battery which was low but not dead, the only thing which enabled me to get past the post and continue boot to Windows and normal operation was removed both RAM modules and then inserting one or both and it would then boot as normal. I have completely dusted all the relevant areas inc the sockets for the RAM and the modules themselves, but the problems persists, if I want a re-boot - its fine, goes through that no probs, but a cold start involves removing one or both RAM modules and then re-inserting one or both RAM modules to enable a boot from cold. I appreciate there are other post on here which are similar to my problem, none seem identical, I would be grateful for any suggestions you might have, inc trying replacement RAM modules which I dont currently have?

Many thanks.

S.

 

I sure hope you are following the necessary ESD prevention precautions when reseating the RAM. That is, you are unplugging the computer from the wall and touching bare metal of the case interior BEFORE touching the RAM.

That said, simply unplugging from the wall should be equivalent to pulling the RAM since unplugging (or flipping PSU's master power switch - if it has one - to Off or "0") is essentially the same thing - all voltages, including the ATX required +5Vsb standby voltage is removed from the RAM and all points on the motherboard.

Whenever troubleshooting hardware issues, you want to ensure you are feeding the hardware good, clean, stable power so I always start by swapping in a known good power supply to see what happens.

The fact you see lights flicker says the power switch itself is working. But flickering lights does not mean all the required voltages are present.

 

Thanks, yes I always touch casing first, so failing PSU is one possibility, guess either swap out or use a dedicated PSU checking tool 1st..?

 

If you mean a PSU Tester, these are great for checking to see if a voltage is missing, or perhaps way out of the allowed ±5% tolerance, they are not good for intermittent problems unless you just happen to be checking when the problem happens.

To properly and conclusively test a power supply unit (PSU), it must be tested under a variety of realistic "loads" then analyzed for excessive ripple and other anomalies that affect computer stability. This is done by a qualified technician using an oscilloscope or a dedicated power supply "analyzer" - sophisticated (and expensive!) electronic test equipment requiring special training to operate, and a basic knowledge of electronics theory to understand the results. Therefore, conclusively testing a power supply is done in properly equipped electronics repair facilities.

None of those plug-in testers test for ripple and they only provide a small "dummy load", not a variety of "realistic" loads. So while better than nothing, using one of these testers is not a conclusive test.

That leaves for most users, swapping in a known good supply to see if the problem persists, or goes away.

 

Right, probably swap out the PSU for a new one and see what happens, I gather this is relatively easy task as long as new PSU is correct spec and from reliable manufacturer.

 

Or beg, borrow or... borrow one from a trusted friend or relative.

Physically swapping out power supplies is one of the easier maintenance tasks. 4 screws on the case's back panel and it comes out.

If your current supply is a standard ATX supply, you have 1000s to choose from. Just make sure it is of equal or greater power output capability. I also recommend 80 PLUS Bronze certified as a minimum. "Gold" if the price is right.

If a factory made computer from Dell or HP or another big maker, and/or is a slim or micro case, it might be a proprietary supply and then your choices are greatly limited, and likely more expensive.

 

Right, Ill have to buy one, the PC is a Zoostorm large format case with loads of room inside and a 250w PSU installed, so guess a standard unit of a higher rating say 500w would do the job.

 

This is the current unit https://microdream.co.uk/fsp-fsp250...pa250cm02.html#product_tabs_additional_tabbed

 

This looks like a possible replacement https://www.currys.co.uk/gbuk/compu...ssic-kl-500v2-atx-psu-500-w-10205457-pdt.html

 

250W? Wow. That is tiny. But if 250W was supporting your hardware, 500W is probably overkill. That said, there's no harm in going too big. The computer (motherboard, CPU, graphics, drives, RAM, fans) will pull from the PSU what they need, not what the PSU can deliver. And the PSU will, in turn, pull from the wall what it needs to power the computer, plus ~20% extra (with 80 PLUS Bronze PSUs) due to PSU inefficiencies.

So if your computer needs 200W, that is what the PSU will deliver and it will pull from the wall ~250W (250 x .8 = 200) even if it is an 850W PSU.

If 250W has been enough, you could easily get by with 400W and have room to spare.

You will find that most experts, advanced and experienced users will tell you to buy quality and not try to cut corners in the budget when it comes to power supplies. EVERYTHING inside your computer case depends on good, clean stable power. For this reason, I like to say you would not buy a new Porsche then fill it up with fuel from the corner Tobacco and Bait Shop. That said, a car engine can miss a beat and keep running. Computer hardware cannot.

So you will sea EVGA, Seasonic and upper tier Corsair PSUs often recommended. I personally have no experience with Kolink PSUs. The reviews I am reading are mixed.

I understand that most people don't want to sink a lot of money into older computers. And your 5 year old PC is getting up there (I hope you have a current backup of your important data!). The price of that Kolink is very attractive but consider the fact you may need to replace the rest of your components soon and if you buy a quality PSU now, you can probably carry it over to your new build.

 

Thanks - I will swap the PSU and let you know how I get on and if the problems remain.

I have already substituted the original HD for a SSD, and regularly back up everything from every source regardless, as you never know when gremlins will strike..!

Many thanks for your help.

S.

 

Sounds like a plan.

 

Well, new PSU installed , same problem, so guess down to one or both RAM modules or the motherboard, might be worth buying one module of RAM to check, but, starting to enter to world of good £ chasing bad £ on a 5 yr old PC, and look at living with it for a while and replacing completely at some stage.

 

Yeah, because it could be the motherboard too and it is likely if you buy new RAM, you will not be able to carry it over to a new motherboard, unlike the PSU.

 

Yes, well still works at mo, if a bit of faffing to boot up..!