PC-UM10M
LL-T1815 TROUBLE SHOOTING
4 – 3
(Yes)
4
(Yes)
Replace the LCD module.
Is the positive (+) side of C162 at DC+12V?
3
(No)
Check IC24 peripheral circuits.
4
(Yes)
Is 7PIN of ICN6 at DC0V?
3
(No)
Check R221.
4
(Yes)
Replace the LCD module
3
4
Is the main PWB LD54 at DC+12V?
3
(No)
Check F3 in the power unit, the power line, and the
FB18 line.
4
(Yes)
Is LD58 at DC+5V?
3
(No)
Check IC14, FB21, D18, and CN8 peripheral cir-
cuits.
4
(Yes)
Is LD56 at DC+2.5V or less?
3
(No)
Check the main PWB and the DC jack PWB in the
peripheral of IC14.
4
(Yes)
Is 1PIN of CN2 - CN7 of the inverter PWB unit at
about 600Vrms? (Use extreme care to prevent
against an electrical shock. Use a high voltage
probe of 100:1 or more for measuring the voltage.)
3
(No)
Replace the inverter PWB unit.
4
(Yes)
Check the lamp in the LCD module.
4
4
Are LD60 and LD61 at DC+5V?
3
(No)
Check the DC+5V power line and IC25 peripheral
circuits.
4
(Yes)
Is LD64 at DC+3.3V?
3
(No)
Check the DC+3.3V power line and IC26 peripheral
circuits.
4
(Yes)
Is LD65 at DC+2.5V?
3
(No)
Check the DC+2.5V power line and IC27 peripheral
circuits.
4
(Yes)
Does the whole display remain black?
3
(Yes)
Is the voltage across fuse F1 at DC+12.0V?
3
(No)
Check F1, IC14 and IC24
peripheral circuits.
(No)
4
(Yes)
Is the oscillating circuit of X1 and X2 normal
(10MHz)?
3
(No)
Check the oscillation circuit of
X1 and X2 in the peripheral of
IC16.
4
(Yes)
Are the signal output of LD20 and LD21 normal?
3
(No)
Execute
2
.
4
(Yes)
Check IC23 peripheral circuits, or CN6 and the LCD
module.
Is the display size abnormal?
3
(Yes)
Are the adjustment items of ADJUSTMENT and
MODE SELECT are properly set?
3
(No)
Set the items properly according
to the LCD display adjustment
procedures.
(No)
4
(Yes)
Check X1, X2, IC15, the peripheral circuits, and the
software.
