Old Dell Optiplex Problem

[Beatnik]

Optiplex 745

Turn on and it turns off and on, off and on over and over quick. Almost starts then the same. 1,3,4 lights come on while it tries to start. Eventually it starts and runs fine.

I've swapped and pulled memory, ran a test and test was good. Did find I had a stick of rank 1 with three sticks of rank 2, so it's now got two sticks of rank 2. Tried it with only the one stick of rank 1 no change. New battery on board. No extra cards. Tried without the cd drive.

Would maybe the hard drive cause this ?

 

[2N697]

How long between on and off? Does it stay consistent with the on-off interval or does it change each time it cycles? I have never seen a hard drive cause this. First wild guess would be the power supply. I have seen intermittent processor fans cause something like this, but normally it shuts off and stays off until you try to reboot manually. Almost sounds like a bad connection to/from the power supply.

 

[SPEC2man]

Here is what Dell says :



Not particularly helpful. I have seen printers with USB ports freeze a boot process if the BIOS boot order has USB before the local harddrive. It will try to boot USB and eventually time out and move to the next boot device on the list? Long shot.

 

[Beatnik]

How long between on and off? Does it stay consistent with the on-off interval or does it change each time it cycles? I have never seen a hard drive cause this. First wild guess would be the power supply. I have seen intermittent processor fans cause something like this, but normally it shuts off and stays off until you try to reboot manually. Almost sounds like a bad connection to/from the power supply.

Few seconds between cycles, then a longer one, then a few short ones maybe a longer one, then it starts. I'll pull and clean all the connections. I deoxited the hard drive connectors last night.

 

[Beatnik]

Caps maybe ?

 

[teal'c]

Try pulling the battery and letting it sit for 24 or so hours. We'd have a similar problem at the college I worked at with probably 25 or 30 Dells out of about 400 and that would take care of it.
Don't remember the model though.

 

[acmmty]

Capacitor plague?

https://en.wikipedia.org/wiki/Capacitor_plague

Look in the power supply and motherboard for capacitors with bulging or broken vents in the top of the can.

 

[Beatnik]

The capacitors aren't visibly buldged, but look at this mess. Something happened there.

 

[dB happy]

The capacitors aren't visibly buldged, but look at this mess. Something happened there.

View attachment 1257425

Something got spilled on it. Looks like coffee. Might be able to clean it up using an esd safe brush, and possibly some distilled water on the tough spots. I've revived lots of spill victims using this method.

 

[2N697]

looks kinda like that electrolytic cap mighta spewed chunks

 

[faber12]

Sounds like a power supply issue to me too.

Could be a bad cap on the motherboard as well.

 

[2N697]

I've seen mice do something like that, but they usually leave behind a few "calling cards". If it was that cap in the middle of the photo, I would expect to see more residue in the area immediately surrounding it. I have seen them spray out in all directions before, but there should be an obvious venting point. I can't see that in the photo. Maybe cola spray as dB suggested? It may work if you clean it all up- especially around those card slots.

 

[sKiZo]

I'd think your problem is it's an old Dell Optiplex ... ;-}

Realistically, you've got your money's worth out of the old beast. Time to move on, eh.

 

[Beatnik]

I'm going to clean it up and lift some caps to check. Found a youtube video of 5 common caps on these boards.

Almost looks like a bug exploded, saw a beetle looking piece ? The slots are for maybe a floppy drive and ? Not used, but that's corrosion.

I'd think your problem is it's an old Dell Optiplex ... ;-}

Realistically, you've got your money's worth out of the old beast. Time to move on, eh.

This is not my main computer, a five dollar hard drive less thrift buy a few years ago. I use a newer 755, lol.

 

[TPettenati]

Search badcaps.net in the motherboards forum

Motherboards with Bad Capacitors

One guy posted a video where he replaced 4 x 2200uf caps to fix a restart problem

Dell OptiPlex 745 automatic restart - fixed

 

[Beatnik]

I've got the board in the sink drying out. Looks like all of the mess came out of the slots with some serious scrubbing and a can of crc.

 

[Beatnik]

Put it back together, same thing. Unplugged the hard drive and it booted right up into bios.

I poked around some and looked at drive settings and sata 0 was off and sata 1 was on. Turned sata 0 on, exited setup, plugged the hard drive back in and it booted right up.

So now I have it unplugged and am going to try again in a bit.

 

[Beatnik]

If I turn it off and back on within a few minutes it boots. If I wait a while it doesn't. I'm guessing it is caps and just going to do them asap.

 

[SoCal Sam]

I'm going to clean it up and lift some caps to check. Found a youtube video of 5 common caps on these boards.

Almost looks like a bug exploded, saw a beetle looking piece ? The slots are for maybe a floppy drive and ? Not used, but that's corrosion.



This is not my main computer, a five dollar hard drive less thrift buy a few years ago. I use a newer 755, lol.

I run a 780 DT. It's one size larger than SFF but not full size. I over spent on upgrades such as Q9650 processor, GTX 745 4GB GPU, 16GB RAM, and a new hard drive. It's faster than I am and does not hold me back.

 

[Beatnik]

I run a 780 DT. It's one size larger than SFF but not full size. I over spent on upgrades such as Q9650 processor, GTX 745 4GB GPU, 16GB RAM, and a new hard drive. It's faster than I am and does not hold me back.

There's something about these I just like. Easy to work on because everything just snaps in and out, small and quiet. My 755 SFF does all I need, trying to setup this 745 to play around with dsp.