I have many of these and they are wonderful!
This particular one has been in service with dual CPUs and 64 GB RMA for almost 10 years on Win 7 Ultimate 64b. Several months ago, I removed the x5670 CPUs and replaced them with a matched pair of x5690 CPUs. I was very careful. No problem. The new chips worked fine and machine was faster than ever. That was December.
The other day (March 26th), the machine only powered up for 3 seconds and **bleep** right down. I had not changed anything hardware-wise and nothing big software-wise.
I took the machine apart and reseated memory. The machine came up as normal. But, after running for two days, it turned off and reverted to the power up for only 3 seconds condition.
I removed the riser for the second CPU and now still running with only 1st CPU and 32 GB of RAM.
How can I troubleshoot the removed riser to find the cause? Thanks in advance.
The T7500 runs with the riser removed? If that's the case, it sounds like you already troubleshooted it. I don't know to what extent a riser can be troubleshooted or fixed other than to replace; but would have to leave it to one of our other experts or Rockstars. You already tried re-seating items which is a good start.
May be this link will help? https://www.dell.com/community/Desktops-General-Read-Only/T7500-Riser-Card-broken/td-p/5061742
This sounds strangely similar to a problem I had with my T5500. After trying unsuccessfully to install a 2nd X5670, it began exhibiting some strange behavior. It wouldn't power up at all. When first plugged in, it would briefly flicker to life then power off. Pressing the power button would do nothing. No lights, no beep, no video - nothing.
Then I cleared the CMOS. And it booted - once. I then went into the BIOS made a few changed and tried to shut it down. But the power button wouldn't shut off the machine, so I yanked the plug. But when I plugged it back in, nothing happened again. I reset the CMOS again, and it booted. But the same cycle repeated.
So what I did is went into the BIOS after yet another CMOS reset and under Power Management set it to automatically power up after power loss. The power switch still will not work properly, but as soon as I plug it in or turn on the power strip, the machine boots up.
TL;DR Try resetting CMOS and see if you can get into the BIOS. If you can, under Power Management see if you can set the machine to resume after AC power is restored.
A low CMOS battery can also cause all sorts of bizarre problems. The T7500 is 10 yrs. old and the batteries last about 5. Be sure to use lithium vs. alkaline. It's a cheap fix and if it doesn't work, you still have a new battery on your MB(s).
Thanks for the reply. The problem seems to have resolved with my reseating some memory, but that only lasted 1 day. Since then I have removed the second CPU riser (and memory on that riser) and the problem seems to be OK for the last two weeks.
Considering this, do you still think I should put in a new battery. I remember repolacing it about a year or 2 ago. Not sure if I used lith battery.
Up to you if you have a battery tester and want to test it. It's a 3v battery. It should show at least 2.7v. Low 2's and it's time for replacement.
Or, if you want, replace it and you know it's ruled out.
It's also possible for peripherals to short or die out when they get older. Glad you got your T7500 running again.
OK, thanks. I am making arrangments to get a battery tester. But, although I have used PCs from the very first Dell, I lack the knolwedge to get the battery out. In fact I have ruined at leas one motherboard in the past. Is there a tooll that I could purchase that gets it out? Thanks.
Removing the battery is in the service manual. As for a tool, I have a set of very small screwdrivers that could be considered jewelry screwdrivers. A regular very small screwdriver is used to push the tab that releases the battery.