This morning, my Precision T7500 had lights 2,3, and 4 blinking constantly with an amber power button. Tried unplugging and letting it sit, but to no avail. Finally I took out the 2nd CPU riser card, and the machine booted. I tried looking up the light codes in the manual, but didn't find anything matching that pattern. Does anyone happen to know, so I don't have to completely rip apart the machine to test the cpu and memory cards seperately? It's a real pain to take off and get the main cpu heatsink reseated and screwed down...
I have a refurbished Dell T7500. I got all nerdy and decided to upgrade the memory. Thought no big deal, so I ordered up some RAM. When it arrived I followed the service guide, slid out the riser, removed the shrouds and installed new memory. Then reversed everything.
I got the same blinking lights.
I thought I had misinstalled the RAM. Maybe bad RAM? Etc. Etc.
But the machine booted fine without the riser. Needless to say I was stumped because I knew all components were fine before the new memory, but the machine would not even boot in the original memory configuration with the riser installed. <more head scratching>
Then the light bulb went off!
THAT FLIMSY PLASTIC RISER TRAY LOOKS LIKE IT HAD SETTLED.
I installed some makeshift shims under the tray. This was to allow the riser card to seat all the way squarely on the sockets and entirely.
Problem solved. The T7500 booted right up with with both CPUs ... All 48GBs of RAM ... just like the champ it was before I was dumb enough to open the case to start with. DOH!
Now I am the proud owner of an 8 core 48GB 6 channeled web browser. 🙂
I hope this helps someone else.
I had this same problem: After installing the new RAM, it wouldn't boot. The power button was solid amber (not blinking) and the front panel diagnostic lights 2-3-4 were blinking, with all the fans eventually ramping up to pretty high speeds. Removing the 2nd CPU riser card allowed normal boot.
I installed a jackscrew.
Full story and more pics are here.