Troubleshooting Guide - HP LP2065 Service Manual

NO POWER
(POWER INDICATOR OFF)
CHECK J303 VOLTAGE
1
PIN5, PIN6 (5V)?
U501 PIN 8
VOLTAGE (5V)?
CHECK KEY CONTROL
CONNECTOR ROUTINE
2
PIN102 (3.3V)
PIN102 (2.5V)
1 3
VOLTAGE ?
CHECK U401 PIN 202
1 4
CHECK U401
Waveforms
1
J303-#5,6 (5V)

TROUBLESHOOTING GUIDE

1. NO POWER
YES
CHECK
YES
IS U401
YES
PULSE
YES
2
U401-#102(3.3V)
NO
NO
NO
NO
3
U401-#102(2.5V)
- 15 -
CHECK POWER BOARD,
AND FIND OUT A SHORT
POINT AS OPENING
EACH POWER LINE
CHECK 5VS LINE
(OPEN CHECK)
NO PROBLEM
CHECK 2.5V AND 1.8V LINE
CHECK X-TAL
4
U401-#202