Computer momentarily turns off before turning on normally

I have this problem with my Desktop PC since past 3 years when I replaced my faulty PSU with Corsair VS550 back in 2017. Everything was perfect before that with the previous PSU.

Since then, every time I turn my PC ON, the front LED light turns ON, CPU and PSU fans etc. start rotating AND then all of them turn OFF immediately and stays in that state for a while (for 4-5 seconds) and then finally TURN ON again automatically and normally (with no manual Switch ON), and PC runs with no further issue. Also the BIOS Settings along with system date/time DO NOT RESET.

This thing happens in case of fresh start of the computer only. When I just turn OFF the computer keeping the UPS still turned ON and then turn on the computer again anytime later (keeping the UPS still turned ON), there is no such issue. But if I switch OFF the UPS along with the computer and go with a new fresh session, same problem happens.

Considering this to be a fault with the PSU, I have installed a new Cooler Master 450W PSU a few days before, BUT again same issue. So this might not be due to the PSU itself (I think).

► To better understand the issue , please consider in watching this video of my PC uploaded on YT: CLICK HERE

Any resolution/suggestion from anybody with knowledge of this issue would be highly appreciated.

Thank you.
My System Information---
Board: Intel DH67BL (Using since 2011)
CPU: Intel Core i5 2310 @2.90GHz
Graphics Card: Nvidia GeForce GT 520, 1 GB
Boots from: Samsung 860 EVO 500GB SSD, Addl. 1 TB HDD installed
Power Supply Unit: Cooler Master MWE 450W (same problem with Corsair VS550W)
Windows 10 Pro, 64-bit



Posts: 829   +201
TechSpot Elite
Annoying for sure. I don't think the Coolermaster PSU is better than the Corsair, however it does sound like the PSU is going into protection mode I'm pretty sure Seasonic makes the Corsair and they just happen to have a little info on that:

Having said all that. I'm not 100% positive this is it because you say you don't have to start it manually, that it just come on by itself and it is good. Whatever is causing the failure it requires it to be off from wall power so it can discharge again.

There is also a small chance that they RAM is set wrong (now?) and it is going through some type of memory training therefore you get that reboot after it sets memory to the default speed.

To recap:

1) It's possible both PSUs have a issue. Get a 3rd good quality PSU? Seasonic or Corsair is good. Not a great option but it has to be considered.

2) It's possible the fault is in the hardware somewhere (other than PSU). Since the whole rig is getting old, it likely isn't worth chasing down since you can easily just leave stuff on. Leave the UPS on etc. Why shut that off anyways? My machines stay on 24/7 since I use them so much. I just shut my monitor off

3) It's possible that the RAM is set wrong now and you could go in and just set it to the slowest/slower reliable speed
Hi! Thanks for your explanation.
The MoBo has dual channel RAM slots (2 Black, 2 Blue) and currently one unit of 4GB Stick is installed on 1st black slot. I have tried altering the stick on other slots.

I also tried by installing the previous memory sticks (2GB+1GB) which I had bought with the PC back in 2011. They still work good, but I don't use them now as I had upgraded the same with 2x4GB sticks in 2018. But the problem started even before that, in 2017, when I changed the PSU. After installing the new PSU, the first thing I noticed was this "power on-off-and back to on" problem, which was not there with the previous PSU. Otherwise, the PC booted normally on 2nd attempt and working in the same way till now.

In the last month I had to remove one 4GB stick as it has some defects.
So, would this "Power ON-OFF-and back to ON" problem have caused the RAM to become defective? (Memtest86 result: error in 1 Bit and in 1 address)

After reading the Seasonic article, I did connect the SSD and the HDD with separate Power cables which were previously connected with a single one. But still same problem.

Regarding keeping the UPS ON, I use my PC constantly for 8-10 hrs a day on average. So in the rest of the time, I keep the UPS turned OFF.

And lastly I would try to check with another PSU, as you have suggested.

Thanks again.


Posts: 829   +201
TechSpot Elite
UPS means Uninterruptible power supply right? When you power that down I think that hurts it's ability to work doesn't it? They have a microprocessor too and some UPS have automatic voltage regulation and surge protect and I'm pretty sure as long as that equipment is plugged into the wall it will be subject to overload just the same as it was 'ON'. When it is 'ON' the UPS can pass the high current to ground (if you have a good ground in your circuit). Honestly, I would leave the UPS to do it's job. In that manner, I would leave the PC on too because of how often you use it. I just shut my monitors off when I step away.

I would not think fooling around with a single stick of RAM would induce any of the problems you describe.