So i have just inherited a poweredge 1550 dual p3 machine which does not post or give any error codes, audable or otherwise.

 

I have noticed that there are a bunch of led lights near the power supply. They are labeled cr3, cr4 ,cr5, cr6, cr7, cr8, cr9, and cr10. Is there documentation for these lights? I am familiar with the ABCD dell post codes, but this system i think predates those. Anyone ever heard about these LED lights on the physical motherboard?

They seem to cycle through like thte machine is trying to boot, and i would hope if i could read them that I would have a better understanding of where it is getting stuck. When i start the machine lots of combinations of lights are displayed, and it finally leaves cr5 and cr10 illuminated. These leds surround a chip with the letters:

P12AB and 74VHC273 printed on it. Something to do with the CMOS i guess.

 

Anyone have any documentation on this? all i can find is info on the ABCD rating located here: http://support.dell.com/support/edocs/systems/dim4600/en/4600/sm/advtrbl.htm#1084976