[SOLVED] (Resolved) Dell T1700 Power Button Failure / Now Occasional No POST / Hardware Issues

[ztrain727]

Resolved by swapping motherboard.

Original thread follows:

Hello Everyone -

I'm having trouble diagnosing what seems to be a hardware failure on a Dell T1700. This is a built up generic box designed for low power consumption video editing, specs are:

Dell T1700 Stock Box, MB, PSU
Core i5-4690k
Asus GTX 1050 OC
32 GB Ram
4 SSD's
Windows 7 64 bit Build 7601

Symptoms:

Power button started failing. Worked occasionally, now doesn't work at all, except randomly a week ago it worked once.

I was still able to boot using the PSU's diagnostic button for a while. Recently, this started to fail occasionally as well. I tried pulling the video card, unplugging all SATA ports, removed all peripherals. This sometimes allowed for POST.

Tried pulling the CMOS battery, plugging in AC, booted successfully a few times but today this wasn't foolproof either.

Currently I am booted from onboard graphics without CMOS battery but with all SATA ports and all 4 sticks of ram. Failed to POST 4 times, but made progress each time. Every time the system POSTs, windows loads no problem, hence my assumption of a hardware failure.

What are my best options for diagnosis? Memtest 86? Prime 95?

I'm suspicious of motherboard failure, but am hoping this is not the case as it's the most labor intensive.

 

[Ralston18]

PSU: make, model, wattage, age, condition?

Check that all power connections and components are fully and firmly in place. They do creep loose over time due to heating, cooling, and vibrations.

Next, try testing the PSU per the following link:

https://www.lifewire.com/how-to-manually-test-a-power-supply-with-a-multimeter-2626158

If you do not have a multimeter and/or know how to use it, find a knowledgeable family member, friend, or co-worker to help.

 

[ztrain727]

PSU: make, model, wattage, age, condition?

Check that all power connections and components are fully and firmly in place. They do creep loose over time due to heating, cooling, and vibrations.

Next, try testing the PSU per the following link:

https://www.lifewire.com/how-to-manually-test-a-power-supply-with-a-multimeter-2626158

If you do not have a multimeter and/or know how to use it, find a knowledgeable family member, friend, or co-worker to help.

Thank you Ralston!

PSU is a Dell L265EM-00, original to the machine. Not sure of the age or hours as I am the second owner.

I re-seated all connections. Booted 4 times in a row, no hick ups. Then I unplugged the PSU, cleared the capacitors, waited, same issue. Won't even POST.

Next I followed your posted guide and checked the voltages on the ATX, SATA and 12v. Everything was right on the money, well within tolerances. Still, can only POST about 20% of the time, and seems to not be affected by what peripherals are plugged in.

An interesting note however. The front panel power button appears to be able to turn the machine off once it has booted. Once off however, the button does nothing. I managed to get it to boot a number of times by hitting the PSU button and then power button shortly after. This then stopped working as well. Any chance a failing power button could be causing these issues?

Once the system boots, it is totally stable. I've run the onboard diagnostics as well as Hot CPU Tester. Neither throw any errors.

My temporary solution is to just use sleep instead of shutdown. It wakes from this state no problem. Only a cold start when the machine is off and the capacitors have cleared does it seem to have issues. I can reboot indefinitely and all is fine. As soon as I've unplugged it for a bit, no dice.

I am looking for a long term solution as I have to unplug the computer from time to time and that puts me back at square one.

Many thanks!
Zane

 

[Ralston18]

Are you able to test the power button?

I.e, power down, unplug, and then use your multi-meter to test the power button?

You have mentioned the CMOS battery - have you tried a new CMOS battery?

 

[ztrain727]

How would one test the power button? It's built into the front panel. Do you mean trying to find the front panel pin out and checking for continuity?

I have not tried another CMOS battery but it reads right at 3v.

 

[Nnyan]

if you trace the two cables from the power button to the motherboard you will see that it's a small jumper going over two pins. Remove the jumper from the motherboard. Then use a screwdriver to bridge the two pins, this should power up your system.

 

[ztrain727]

Thanks Nnyan! My other custom built workstation has a two pin power button like this, but Dell bundles all the font panel connections into one single plug. Maybe I could find the pin out and try what you mention.

 

[ztrain727]

Sorry to dig up an old thread, but I finally got around to this again and swapped the motherboard. Problem solved. I noticed the power button connect was sliding off it's pins. i bet this is where the trouble was, as the power button works normally now. Didn't notice any play before.

Hope this helps someone down the line.

 

[lynx1021]

Yes, connections can get loose over time especially if there is vibration. My P43T quit a couple of months ago and I thought it was the 24 pin again but turned out to be the connector on the board that goes to the power button this time. The desk it sits on is near the wall with a old window AC that has some vibrations.