Motherboard failure issue on Dell Optiplex 980

I have a problem with a batch of Dell optiplex 980's, for some reason the Main boards fail at a alarming rate.

According to Dell it is the memory controller that fails.

Error Lights 1,3,4 are on nothing on screen, power led solid blue about 10 error beeps!

Dell tech replaced the main boards and all is fine for a while but same problem persists.

Also according to Dell level 6 tech, it could be over heating, I had some fun proving them wrong, two PC's sealed in a box , hammering them, Temp between 85 Celsius - 90 Celsius in the sealed enclosure, optical drive started melting, cooled the PC's for a day and powered back on, no problems!!

Does any one out there maybe have a issue similar to this on the optiplex 980, main board failures?

Dell Optiplex 980 Lights 134 on no screen

Yes I have exactly the same problem. Turned PC on this morning lights 134 on plus blue power light but no screen at all. Still under warranty, phoning dell in the morning - I will keep you posted

romansway Dell 980 environment

Hi romansway, can i ask you to describe the environment you are using your optiplex 980 in? Physical location, temp, etc?