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Dell Precision T5500 flashing 2,3,4 and Amber light

Hello to all the experts...I recently just logged off and shut down my computer. When I went to power it back on, I get a steady diagnostic 2,3,4 green flashing and solid amber power on/off light. Replaced power supply with refurbished, still the same problem. Then Dell support says to try and replace the input/output board so, ordered that one with refurbished with new cables, same issue. Some other things done were removing the CMOS battery and re-start, no luck, re-seated all memory, no luck, checked all connections, good...I am told it is possibly the motherboard but, just want see if anyone has any idea's before I order one of those...Thanks in advance for any support provided!!! 

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6 Replies
8 Krypton

RE: Dell Precision T5500 flashing 2,3,4 and Amber light

Hi RT51007,

Here's your service manual: ftp://ftp.dell.com/Manuals/Common/precision-t5500_setup%20guide_en-us.pdf

Those diagnostic lights indicate "USB subsystem configuration activity in progress or USB subsystem failure" according to your service manual. So a motherboard replacement may be necessary.

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Cheesus J C
2 Bronze

RE: Dell Precision T5500 flashing 2,3,4 and Amber light

I have read allot of posts about this same error and have finally figured this out.

Dead CPU...

Time to buy yourself an X5650 or alike.

I was trying to get to the bottom of this a long time ago and threw away a perfectly good T5500 system as I figured the MB was at fault.

I checked every capacitor ready to replace any broken component, At the time I put it down to a fried IC.

Though I ended up keeping the cpu and before I put it on Ebay tonight I though I should test it first in another T5500 system I still have... same error 234 flashing, solid amber power light.

I smiled and almost spewed at the same time.

To be honest I'm a little disappointed that this error is not better documented by Dell.

There is absolutely nothing in any tech manual about this being a faulty CPU.

The actual error refers to something else completely.

The T series workstations are fantastic even still today and I still use them, the only other problem I have had with the T5500 is that even with latest firmware and drivers ATI 290X fan will not spin up.. ever, Even manual overriding it. Just overheats and '41 kernal power' due to heat.

Not sure about Nvidia cards

Last gen cards like 7970 work really well though.

I guess the 5 year gap between hardware doesn't mesh well, Though that is to be expected.

Hope this has helped someone.

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2 Bronze

RE: Dell Precision T5500 flashing 2,3,4 and Amber light

I just got This T5500 its the same problem. I need help. I been double check all the connection and nothing change.      Its use and the guy say was working properly good.

But Not at all. help

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2 Bronze

RE: Dell Precision T5500 flashing 2,3,4 and Amber light

  I had this problem twice - when I first got my used  barebones T5500 in the mail!

First time was out the box - turned out the CPU was not quite seated correctly. Re-seated it and applied new thermal paste, and it booted up fine.

Second time was after installing the second cpu: 

This time the cpu itself was fine,  but I found  riser connection can come loose on occasion. By sliding it out and then carefully back in again (ensuring the connectors are lined up before you raise the handle), this would  fix the problem.

Sometimes it would take a few attempts -  It  does re- occur from time to time though, usually after I've moved the PC from place to place or if its been bumped around by anything. 


2 Bronze

RE: Dell Precision T5500 flashing 2,3,4 and Amber light

I had the same problem while i had riser with second CPU installed (6 x 4 GB DDR3 DIMMS, 3 dimms on riser+ 3 dimms on mainboard, populated in the following order: MB_DIMM1, Riser_DIMM1, MB_DIMM2, Riser_DIMM2, MB_DIMM3,Riser_DIMM3, MB_DIMM4)

Problem 1:

1- Off
2- Blink
3- Blink
4- Blink
ACPI S0, hand off
to BIOS control System on. BIOS not execution. This is the transition state to POST states.

Nothing on screen.

After i pressed a little bit into the riser and plug out and plug in.

S3 Led 3 si 4 Solid Green. Memory subsystem configuration activity is in progress. Appropriate memory
modules were detected but a memory failure has occurred.

Nothing on screen.

After i placed the PC at horizontal and turned off the PC and then turned ON again.

SURPRISE!SURPRISE!SURPRISE! The pc started to display bios and then booted into windows.

So. Place your PC HORIZONTALLY after you installed the riser with the second CPU.

2 Bronze

RE: Dell Precision T5500 flashing 2,3,4 and Amber light

Thanks for posting the follow up. Identical problem, seems CPU paste on the riser CPU got flakey, re-seated and presto changeo - all back to normal except for the bald spot where I was pulling my hair out for 3 days. Most appreciated.

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