You could try running the diagnostics to see if there are any errors (tap the F12 key at start-up, then select from the menu)

Try disabling automatic restart on failure:

http://www.tecknowledgebase.com/6367/how-to-disable-the-automatic-restart-on-system-failure-in-windows-7/

If there is an error in Windows you may then get to see what is causing it. Let us know how you get on.

hi,

i'm using Dell t3500
without playing games work fine but when i playing games my t3500 workstation rebooting after 10 to 20 minutes - and no any light blinking sign

English is not my native language so please excuse any mistakes

12 gb ram

PNY GTX 460 1gb

hdd WD 2tb

hdd WD 500 gb

Try to put your cpu under stress for 20 - 30 minutes 

https://cpux.net/cpu-stress-test-online  , this could do it simply I think. And use hwinfo to keep an eye on the cpu temperature.

If the system doesn't reboot, look for a test for the ram. if no issues is likely the gpu ( look for a test for the gpu at that point )

Can the power supply of Dell T5500 be used in Dell T3500 ?

sorry for my bad english

Computers often reboot when there is something wrong with RAM, or CPU. CPU usually is not the case, when assembled once at the factory and not touched.

Since you have a ECC RAM, go to BIOS, and check logs for RAM errors. If there are none, and the RMT feature is turned on, that means that the problem is beyond RAM. Maybe the PSU, etc.

But if there are ECC, or more serious errors, see the slot where it happens, and remove the faulty DIMM.

Why not CPU... there are a score of overheat protections in modern Itel CPU's, so it goes to throttle first, and... many things happen, but it will let you know when overheated. It will be in the same log. But if the power pin is broken, or bad, or the CPU package was damaged when disassembling, that may leave no traces in logs, just an occasional OS kernel halt will happen.

For troubleshooting OS-initiated reboots, check the event viewer. If not obvious, install the MS debugger from the Visual Studio, and install the KDFE script (fix there the path to the newest debugger version)
https://asuhovey.wordpress.com/2007/01/28/kdfe-cmd-a-simple-kernel-debugger-front-end/

Kdfe provides you with an automated crash reason analysis.

>but when i playing games my t3500 workstation rebooting

So if the culprit is your GPU, you will see the GPU driver name at the output of kdfe.

I just found the reason.....it's the USB and power button board .....needs to be changed , worked for me

How did you come to that conclusion? How did you know that USB & power button board is problematic? 🤷‍

My T3500 keeps rebooting, and then lights 1 and 3 blink. That indicates a problem with the memory, but it does not seem to be a memory module for the following reasons:

1. I removed all of the memory modules, put them on another T3500, run a memtest and they're all good, and also left them on the other computer to test it, and it works fine.

2. I put all of the memory modules from the other computer (which work fine, and also passed the tests) on the computer with the problem, and it keeps failing. 

3. I tried just one module (any of them) on the computer that fails, and it keeps failing.

I thought it might be something else, so I changed the mouse and keyboard, and disconnected everything I could disconnect (speakers, any usb sticks, internet), and the problem remains. I changed the monitor cable, the power supply cable, and plugged the computer on a different socket, and that does not have an effect, either.

I would appreciate any suggestions.