Installation guide

Troubleshooting
Getting Started with Troubleshooting
1-11
❏ Check that there is approximately 290 Vac, 40 kHz signal at CN2-1. (This check should be made with the
A4 Inverter connected to the A2 Display.)
— If the signal is present at the A4 Inverter output, replace the A2 Display.
(Refer to “A2 Display” on page 2-10.)
— If the signal is not present at CN2, use a DVM to measure the signals shown in Table 1-4 at CN1 on the
A4 Inverter. Probe CN1 from the top of the connector while it is still connected to the A3 Front Panel
Auxilary Board.
— If the signals in Table 1-4 are correct, replace the A4 Inverter.
(Refer to “A4 Inverter” on page 2-16.)
— If any of the signals are incorrect:
a. Using a DVM, measure the signals shown in Table 1-5 at J30 of the A23 Motherboard.
— If the signals in Table 1-5 are correct, replace the A3 Front Panel Auxilary Board.
(Refer to “A3 Front Panel Auxilary Board” on page 2-14.)
— If the 5.2 VD_LCD line is incorrect, refer to the “ILT-1 Power Supply Failure and Self-Test” on
page 1-4.
— If either the LIGHT_EN or VDISP are incorrect:
a. Using a DVM, measure the signals at J15-37 (LIGHT_EN)
or J15-97 (VDISP) of the A23 Motherboard.
— If either signal is incorrect, replace the A12 CPU.
(Refer to “A12 CPU” on page 2-30.)
Table 1-4
Signal State
CN1-1 5.2 Vdc
CN1-3 LIGHT_EN >3 Vdc
CN1-4 VDISP Brightness = 50, VDSP < 50 mVdc
Brightness = 1, VDSP = 3 Vdc
Table 1-5
Signal State
J30-32 5.2 VD_LCD 5.2 Vdc
J30-20 LIGHT_EN >3 Vdc
J30-30 VDISP Brightness = 50, VDSP < 50 mVdc
Brightness = 1, VDSP = 3 Vdc