Windows 7 Computer will not turn on


Well-Known Member
Feb 21, 2012
My power supply died, so i stuck in extra in. It dis more than the other but no lights worked nor did the power button have the ability to turn it off. Im hoping i didnt break thee mobo but it is possible. The fan and disc drive and hdd ran, but no lights. Please help!!!

Well, you didn't tell us anything about your system, the PSU, or the motherboard. Note most motherboards require 2 and sometimes 3 connections directly from the PSU. Typically a large 20 or 24 pin connector, then 1 or 2 smaller connectors.

Many graphics cards require additional power connectors.

The PSU is a Logisys (sort of generic) and the mobo is an MSI K9N6PGM2-V2. It has a 4 pin for the CPU and the normal 24-pin. Opened up the Logisys and found a blown capacitor. Hooked up a different PSU (lower wattage, 115 V.) and now the lights don't work. It is definitely not posting because there are no beeps. Everything powers up that i connect but the lights still don't work and the power button after i click it does not do anything (including holding). It had shut down after overheating and it had also had a problem when it shut down, there was still power to the USB ports?

lower wattage, 115 V
And the other was a 115V PSU too, right? Lower wattage is fine, as long as it is enough to meet the minimums.

Note PSUs must provide 12, 5 and 3.3VDC. The loss of any will cause problems.

they both are, but the light are not turning on...the button does not do anything after the computer is started and there is no post. Does this mean my PSU an Mobo need replaced. Would i be able to use a 650W PSU?

If you decide that the motherboard needs replacing, don't buy another MSI. I've had several and they were nothing but trouble for me.

I might still get one, i have always had good luck with them. BIOSTAR is the type i will never get again.

I agree with MSI. Until Man can create perfection 100% of the time, there will always be imperfect samples - even from makers with the best reputations.

But also it is important to note that OEM Windows licenses are NOT transferable to replacement motherboards unless the motherboard is the EXACT same brand and model number board. The ONLY exception is if the original board is no longer available, but even then, you must use the recommended replacement from the same maker. Again, that's for OEM licenses of Windows - the most common. So, if the installation disk is “branded” with a computer maker’s brand name, or is labeled with “OEM", "OEM/System Builder”, “Upgrade”, “Academic Edition”, or "For Distribution with a new PC only", is not transferable to a new PC (or upgraded motherboard) under any circumstances. These OEM licenses are inextricably tied to the "original equipment". And most importantly, as users, we agreed to the terms of the end-user licensing agreement (EULA) when we decided to continue to use the software on the original computer. And that makes it legally binding.

Would i be able to use a 650W PSU?
I don't know. I don't the full specs of your computer to know the power requirements.

I will say this, there is no such thing as too big of a PSU. If your computer needs 300W, it will draw from the PSU 300W, regardless if the PSU is a 450W, 650W, or 1000W PSU. And the PSU will only draw from the wall 300W, plus another 45 - 90W due to PSU inefficiencies, wasted in the form of heat.

That said, a decent 650W PSU is typically more than enough for most users - if it's working.
Does this mean my PSU an Mobo need replaced.
That is hard to determine even if the computer is sitting on the technician's workbench. It could be the PSU or motherboard or even the CPU. Sadly, there are no simple tests to determine which - other than swapping in known good parts and that always comes with the risk of destroying those parts too!

But as a technician, I always want to ensure I am providing good power to my hardware before I even think of replacing other components.

Did you get POST beeps before when it was working okay? Not all motherboard have integrated system speakers, or are connected to a case speaker.

Yep, used to get post beeps, the computer has a separate MOBO speaker which is now not giving the beeps

Well, then no beeps is not a good sign and it may be time to take the system to a shop where they have spare parts they can swap in to help pinpoint the problem.

Got a new PSU and MOBO installed and now it is starting up and (not really) running fine. Here is the link to the new problem.

Link Removed

Please help!