Maintenance and Service Guide: HP ap5000 All-In-One Point of Sale System

Solving VFD (Vacuum Florescent Display) Problems
The VFD on the HP ap5000 system is connected via serial interface. When attached at the HP
factory the VFD is installed on COM2 as the default location and COM2 is set to 5V mode. The HP
ap5000 VFD can be connected either on COM2 or COM1 on the ap5000 unit; it cannot be used on
COM3.
Windows operating system supports serial port COM1/COM2, so no extra drivers are needed to be
installed.
If you encounter VFD problems, see the common causes and solutions listed in the following table.
No scrolling message on VFD when computer is powered on.
Cause Solution
Serial port used to connect VFD is not configured properly or
disabled.
Configure the serial port from F10 Setup:
1. From F10 Setup select Advanced > Super I/O
Configuration.
2. Verify the settings for the serial port for the VFD.
3. Enable 5V for the serial port to which the VFD is
attached.
4. Remember that you cannot use Serial port 3 for the
VFD.
5. If problem persists, connect VFD to known good
working system.
6. If VFD fails to work on known good working system,
replace VFD.
VFD is plugged into incorrect serial port. Plug VFD into correct serial port (refer to the port labels on
the system):
●
COM2 is adjacent to the printer port.
●
COM1 is between the keyboard port and COM3 (COM3
cannot be used for the VFD).
26 Chapter 4 Troubleshooting