Random system freeze/slowdown

[makijo]

Hi, made a cheap self build comp a few months ago, been working fine since i built it, no lag, crashes or errors.
Suddenly it looked like the system had frozen, i tried moving the mouse and the cursor would move to a different point on the screen after about 5-10 seconds of delay and nothing else was responsive. Tried using the reset button, no response, no response off the power switch either. Had to turn it off at the mains. Then I switched it back on. during the boot up the mb menu came up saying it had detected a power surge during the last start-up and sent me through the mb settings screen to save and restart before it would boot normally.
The manufacturer of the psu claims it has in-built surge protection, but if it did why would this happen?

 

[house70]

The built-in surge protection is supposed to save your motherboard from a power surge, of course the PSU is taking the hit in that case; since PSU's are cheaper than motherboards, CPUs etc. it's a good measure. If the PSU has detected the surge, survived it and reported it it means it just did it's job.
I always place a surge protector on the power line before the PC is plugged in. They are even cheaper and take the first hit before the system does.

 

[makijo]

Ok, so it was most likely the psu picking up on the surge and stopping power to the rest of the system briefly causing the whole thing to basically lock up until the mains supply was reset?

 

[house70]

Yes, the system was trying to save system files and other data to the HDD to prevent corrupting the files. Use an extension cord that has power surge protection built in, that should give you an extra level of protection.

 

[makijo]

Okies, well it is plugged into a strip with a surge protector but the strip is a few years old so i guess they could have worn out by now and the surge got through to the power supply, so will look into getting new surge protectors.
I guess what threw me with this situation is i assumed in the event of a power surge the system would just restart rather than almost completely freeze up and require the plug socket to be turned off to turn the whole system off.

 

[makijo]

Was wondering also just why a freeze would stop the power button working even with the hold down for x-seconds method.
I've had system crashes on other comps before but was always able to hard reset with the power button.