onsdag 29 maj 2013

Bad capacitor in a Dell PowerEdge 860

The title says it all, but I'd like to share the whole story if someone else stumbles over a Dell server with a bad capacitor.

This server was brought to work by my boss, it was meant to be put in our rack here and do the work it previously did at the first location.

But he told me that he tested it before he left and then it didn't start. it had been running fine 2 hours earlier and had not been shut down in a long time before that.

So I began looking at the server, when I plugged the power cable I could hear the fans started in idle mode,
power led was blinking as in idle mode. no problems so far.
I pressed the power button and I could hear the hard-drives starting up, the power led had a steady light, hard-drive led steady too and the "i" led (System status indicator) was blinking/flashing.
There was nothing else, no lights in the Diagnostic indicators, as you can see from this picture:

I took a copy of the data from the hard-drive before doing anything else.

Then I started to debug, removed the fans to CPU and a few plastic pieces and saw the bad cap right next to the CPU, suspecting that was the problem but I did some troubleshooting on a few other parts first, because I didn't want to solder on the motherboard before I had checked everything else possible to check.
* removed the Raid-controller
* removed the CD drive
* removed RAM
Not much more I could do because I didn't have a spare power supply.
Found an other blog-post about a bad capacitor in a poweredge so I guess its not that uncommon and Dell had bad reputation about their bad caps a few years back.

Here is the motherboard with the CPU fans removed, and a red arrow pointing at the bad cap

Two close up pictures of the cap:

I solder it away but just heating the pins on the other side and pulling the cap away.
Here you can see that the bottom side of the cap has been pulled out a little too:
(my blue hands is because of the work I did on my 1957 Chrysler, painting the dashboard

I actually had a few new 6.3V 1500µF capacitors at work, it wasn't the same shape but close enough removed the CPU heat-sink too and put in some new thermal compound.

Cleaned out all dust and old bugs with "air in a can",
put everything in place and tested and it booted just fine!