Optiplex 780 Shuts down

[CornellSean]

Help - I am trying to get a Dell Optiplex 780 from shutting down at random. Details copied from the system specs: srv tag DKTTDP1, small form factor, vPro system, HARD DRIVE, 250GB, S2, 7.2K, WESTERN DIGITAL, XL320; processor PROCESSOR, Q9400, 2.66, 6MB, YOR, R0; graphics card: 256MB ATI RADEON HD 3450 Graph ics Dual DVI and TV Out, Low Profile, for the OptiPlex 780 Small Form Factor and Desktop.) I bought it cheap out of warranty from work for my kids. At first it would power on, but stall in early stages (Bios or post? it would not boot to windows or communicate with the monitor). It gave a series of three beeps, and the green 3 and 4 LED lights. Every website and person I spoke with said this was memory, likely RAM. So we upgraded the two RAM cards from 2 2GB cards, to 2 new 4GB cards (got these from Memory America and details here: 8GB Kit (2x 4GB) DDR3 1333MHz PC3-10600 Non-ECC Unbuffered 240-pin Memory.

There was also some advice on various chat sites about shut down caused by possible power problems with plug strips and with intensive video use. So I plugged it straight to the wall with no strip, and removed one of the two monitors it was originally set up with. We installed windows 10 OS and a netgear wifi card, and, it worked! (for a day or so...) While it was working, I also updated the Bios to version 15 which was recommended, and I ran the Dell Diagnostic Assist (quick test 10 minutes) website on it - all the systems (drives and pattern tests) passed. That night, I left it on in sleep mode and it woke up fine the next AM. So I thought I had saved the republic.

But even with the new steps, the computer still shuts off at random. I just booted it up again, it booted to windows fine, I logged on, opened Chrome and started to look into the system details for this post, and it shut down and gave me the dreaded three beep, three beeps, maybe one beep, three beeps....etc. Now it shows the green 3 and 4 lights again.

Also, it seems that it will stay on for a while when it has not been running for 30 -45 minutes. In that case I can boot up, log on to windows, run a website for a few minutes and then crash.

But immediately after that crash, I have to do a hard shut down to power off. I wait 2 minutes or so until the 3 4 LED lights are off. Then I reboot and it may boot up, but sometimes then it goes right into the beeping and 3 4 LED error lights again.

So I think there is something related to the time it has been running? Could this be a heat problem? Or some other hardware problem? It is very quiet - maybe no fan is running to cool it? I do not know how to test hardware like the fan / cooling. On my other desktop you can hear the slight hum and feel the slight airflow. Maybe this helps diagnose?

We need some stability in this droid...
Help us Obi Wan...

 

[CornellSean]

Also, it seems that it will stay on for a while when it has not been running for 30 -45 minutes. In that case I can boot up, log on to windows, run a website for a few minutes and then crash.

But immediately after that crash, I have to do a hard shut down to power off. I wait 2 minutes or so until the 3 4 LED lights are off. Then I reboot and it may boot up, but sometimes then it goes right into the beeping and 3 4 LED error lights again.

So I think there is something related to the time it has been running?

 

[CornellSean]

Update - I still need help. I thought it may be related to the browser - so I started using IExplorer instead of Chrome. With that, it stayed stable for a longer time (probably two days); then it shut down again - now I cannot turn it on at all. I was able to run the full Dell Diagnostics on it and everything checked out - memory, video, etc. So I am thoroughly confused why it will not turn on now. Any help would be great.

 

[william p]

Run it with the side cover off. . The fan will be behind the grille in the front of the case. See if air is coming out of the back end of the plastic cover over the cooler. Check that the 4 wire fan connector is tight. If no air replace the fan and hope there's no damage done. replacing the fan requires removal of the cooler assy. so have thermal paste and cleaning wipes ready. The fan holder is usually held in with 2 plastic lock levers tha t need to be lifted.

 

[CornellSean]

Thanks William. The fan seems to be working fine. I tried replacing the CMOS battery and that seemed to do the trick. However when I shut it all the way off and turn it back on it says "Voltage is low" press F1 to start, F2, F3 etc. I hit F1 and it runs fine now. Not sure if this is going to cause me problems down the road.

 

[william p]

You might want to pick up a spare PSU. Old Dell PSUs are cheap enough to keep a spare around.