X5-COM in PC prevents boot

nbuckland · Joined: 17 Aug 2010 Posts: 4

We have found that in some cases, attempting to use an X5-COM in a desktop PC (using the XMC to PCI express carrier card) causes the PC to stop booting - even the BIOS fails to complete, and the graphics card does not output any information (I presume it does not get initialised).

Have you seen this before? Do you have any suggestions?

rvanbuskirk · Joined: 20 Jul 2009 Posts: 181

Check to see if U34 device is installed. It is a PROM intended to change some modes of the PCIe bus, but is no longer needed. If it is installed, we have seen that some PC's will work and others have the fault signature as your system.

U34, 8-pin PROM, location can be found on the bottom side of the board, near the JP2 connector. It should not have a part installed on it.

nbuckland · Joined: 17 Aug 2010 Posts: 4

There is indeed a device in the U34 position. What would you suggest?

nbuckland · Joined: 17 Aug 2010 Posts: 4

In fact, I just checked all four of our X5-COMs, and they all have the U34 device fitted. What exactly does the device change about the PCIe configuration?

rvanbuskirk · Joined: 20 Jul 2009 Posts: 181

I suggest removing the parts from the U34 location on all four of your X5 modules and any other X5 modules you may have. We now have a change order to leave the part off or take the part off on our X5 Series modules.

I'm not sure about the particular modes that the PROM was intended to set, only that the part was put in the design for that purpose. The parts are blank but tend to cause problems in some PC's.

Ron