Computer turns on but wont stay on longer than 30 seconds after power outage

Ruddman20

Reputable
Jul 28, 2015
4
0
4,520
1
Hello, I recently had a small power outage and now when I turn my computer on it will only stay on for 30 seconds or less(varies) before turning off. I ran thru the checklist, breadboarded, and still cant figure out what problem is. I tried plugging computer directly into wall to cross off surge protector as issue. Swapped out and tried another power supply, tested with 2 different GPU's(280 & a 770), tested with only 1 RAM stick in(rotating with 4 others). Seems to POST as it only has a single beep for the code. No idea what issue could be making it turn back off before fully getting into Windows. I'm far from a novice on computers, so any help or suggestions would be great!
 

sirstinky

Honorable
Aug 17, 2012
637
0
11,360
141
You were on the right track with swapping around the memory modules, switching PSU's, etc. The main issue I've found in that diagnosis is the power supply failing. The fact you get one beep on POST which is normal, tells me that it's trying to boot normally, but something is preventing it from loading the OS. It could be that something in your motherboard went south in the power outage. You might want to change your CMOS battery and clear the BIOS out. Other than that, it sounds like a component on your motherboard died.
 

Ruddman20

Reputable
Jul 28, 2015
4
0
4,520
1


Hello, and thanks for your reply. I was initially leaning towards power supply as well. I had a spare lying around and computer had same result with it. I didn't "swap" my CMOS battery but I did remove it for quite awhile to reset it to no avail. I'm now starting to think it is motherboard, just wish there was a more definitive way to test so I don't buy an unneeded part. Thanks again.
 

westom

Distinguished
BANNED
Mar 30, 2009
931
0
19,160
53

No posted reason says anything should have been suspected. For example, what determines when a PSU powers on or off? Power controller. How many suspects were accused without even knowing that a controller exists? If power turns off, what do you think causes that power off? Without numbers from a meter, some requested instructions, and minutes of labor, then you have no reason to suspect anything.

You have two choices. Get facts that, when posted to others who really know this stuff, will identify what is defective before replacing anything. Otherwise ignore all recommendations. Just start shotgunning - keep replacing good parts until something works. Previously, shotgunning was recommended because so few even know of the power controller or how a power system works. Those are your only two choices.


 

sirstinky

Honorable
Aug 17, 2012
637
0
11,360
141


Yah. You cleared CMOS, so that's good.

With motherboards they are so complicated that it's really not worth it to repair it. That's why they just toss them out and give you a new one on an RMA. I'm thinking an IC or transistor got damaged. The only thing you can do is to look for bad capacitors (bulged, weeping electrolyte) burned IC's (resistors, diodes, etc.), or run self diagnostics. You might want to look up the motherboard's user manual or see if you can find a way to get the motherboard into diagnostic mode where it will give you beep codes. There could be a function in the BIOS where there's a diagnostic tool. I've worked on Dell PC's and that's how you find any faults with beeps and BIOS diagnostics. Other than that, I don't think there's anything else I can suggest. If your board is under warranty, get ahold of support and see what they suggest.
 

westom

Distinguished
BANNED
Mar 30, 2009
931
0
19,160
53

CMOS battery stores parameters (that the BIOS first uses on power up) only when power is off. If CMOS battery is defective, then clock has wrong date time. If BIOS does not like those CMOS parameters, then it uses its own default parameters, verifies memory and other parts, and then boots the system. IOW all CMOS information after an initial read is irrelevant.

You have as much reason to suspect a motherboard as you do everything else including GPU, keyboard, any USB devices, and monitor.

Dell is one of few manufacturers that provide hardware diagnostics to actually identify failures. Diagnostics that execute without any OS. BIOS is only a quick and dirty configuration check - not a very good diagnostic.

Using a meter as described provides numbers that identify or exonerate suspects - including the power controller. Most every failed part has no visual indication. Without those numbers, the fewer who even designed computers can only remain silent. Leaving shotgunning as your only alternative.

If not using a meter as recommended, then just start randomly replacing parts until the anomaly stops. Without those numbers (or those superb Dell hardware diagnostics), then nobody can say what is or is not defective.

Only item that causes a PSU to power off is the power controller. Not CMOS battery, memory modules, or anything else.
 

Similar threads


ASK THE COMMUNITY

TRENDING THREADS