Specifications

LQ-2080 Revision A
Troubleshooting Unit Level Troubleshooting 42
5.3 Unit Level Troubleshooting
The information for this section is the same as for the LQ-2070 except
for the point below:
Point: Main board number
5.4 Repairing the C166 PSB/PSE Board
See LQ-2070 Service Manual.
5.5 Repairing the C273 Main Board
This section provides instructions to repair the C273 Main Board
assembly. It describes various problems, symptoms, likely causes, and
solutions. The checkpoint column provides proper waveforms,
resistance values, and other information for each component of C273
Main Board.
NOTE: This information is necessary only for servicers who repair to
the component level. Servicers who repair to the unit level
(including all servicers in the U.S.) can ignore this section.
Table 5-2. Repairing the C272MAIN Board (1/3)
<LQ-2070> <LQ-2080>
C186 Main Board
→
C273 Main Board
Problem Cause Checkpoint Solution
The printer does
not operate at all.
Reset IC2 is
defective.
Check the voltage
waveforms of the VCC signal
(CH1: IC2 pin 3) and VOUT
signal (CH2: IC2 pin 1) when
power is turned on.
Replace IC2.
The PROM
(IC10) is not
selected.
Check for a change in the
signal from HIGH/LOW at pin
22 of IC10.
Replace IC10
(or replace the
main board).
The PSRAM
(IC8) is not
selected.
Check for a change in the
signal from HIGH/LOW at pin
22 of the IC.
Replace IC8 (or
replace the main
board).