Problem with new case+PSU!!!!

[Aya Brea]

My previous case+PSU (250w) run my Cely300A@450 without any problem but when I buy a new case+PSU (300w) it shutdown my PC after 2 or 3 minutes running!!!

I decide to run my Cely at its original speed and it run very stable (with new case+PSU).... My new case has no fan on it, so I think it's heat problem. Anyone know this problem before??? Can you tell me...

[klosters64a]

It sounds like a thermal protection feature of your new PS is shutting it down.

You really gotta get with the case fan plan. If that's not possible, remove your left side case cover and put a house fan near your box, then aim it at the case's interior. Turn it on and leave it on until you can add at least one intake, plus one exhaust fan to your case.

[Aya Brea]

I think it's because of lower voltage that my new PSU provide. Because my PC can stand as long as 1,5 hour before it shut down (when I aim a fan direct to it, and the room temp is 20C). I going to change the PSU and try again...