TROUBLESHOOTING GUIDE
D-3
No
DOES NOT LIGHT ON DISPLAY
Is the voltage at pin 1 and
2 of V651 about -11V?
Check FI)
line of POWER BLOCK.
Yes
Is the voltage at pin 31 and
32 of V651 about -14V ?
No
Yes
Yes
Is the voltage at pin 13
of IC651 about 5V?
Check AT+D5V line of
POWER BLOCK.
No
Is the voltage at pin 30
of IC651 about -18V?
Yes
Check -20V line of
POWER BLOCK.
No
Replace V651 or IC651.
Check FILAMENT(-)
line of POWER BLOCK.
