PCIe2-2712 PCI Express Gen2 Expansion System User’s Manual
4-1
Revision 1.0, February 2015
CHAPTER 4
TROUBLE SHOOTING/SYSTEM OPERATIONS
4.1
PCIE LINK ISSUES
A PCI Express subsystem is comprised of a series of point-to-point connections. On start up, the
devices on each end of each connection establish a link with each other through hardware mechanisms.
Once linked, communication between the devices can occur. However, hardware problems can prevent
the PCIe devices from linking properly.
On the PCIe2-2712 expansion system, the link status is between two devices is presented to the user by
an LED (see section table 3.2). The potential LED states are listed in table 3.1 of this document. If an
LED is not on after the PC boots, or is blinking at random intervals, then a hardware problem is
occurring. Potential causes of a PCIe link issue are:
Table 4-1. PCIe Link Issue
4.2
BIOS CONCERNS
Per the PCIe specification, the PC BIOS should be able to handle the additional devices added to the
system via the PCIe2-2712 expansion unit. However, on occasion, a BIOS may have a bug that prevents
the system from allocating resources to all devices during the PCIe configuration process. Symptoms of
this include:
- PC won’t boot with expansion unit installed (monitor may not power on, or BIOS will hang)
- O/S will hang during boot sequence (typically during device driver initialization)
- Device Drivers will fail to operate properly for some of the boards installed (evident via
Windows Device Manager)
- Installed devices missing in Windows Device Manager
Cause of Problem
Links Affected
Potential Solution
PCIe cable is not fully inserted on
one/both ends of the cable
Cable
Carefully apply pressure to the cable while
inserting it until it clicks into place.
Incompatible host system
Cable
Update BIOS and adjust BIOS options
concerning PCI Express, or use
alternative host system
Expansion system power supply
not turning on
Cable/Slots
Ensure cable is fully inserted, then
contact Cyclone Microsystems
No add-in card is installed in a
given slot
Slots
No problem - Link LED should remain off.
Add-in card not seated properly
in PCIe expansion slot
Slots
Carefully apply pressure to the top of the
add-in card while inserting it until it click
into place.
Auxiliary power connectors not
installed on add-in cards
Slots with
GPUs installed
Connect the appropriate 6 or 8-pin PCIe
power connector to GPU.
