CONFIDENTIAL
LTM1555(B)/LTM1755(B) 5-1
5 Troubleshooting

5-1 No Power

Does proper DC 14 V appear at
DC jack connected to CN12? Check SMPS PCB and Adapter.
Yes
No
Does proper DC 5 V appear at
Pin 2 of IC11? Check IC11.
Check IC23.
Yes
No
Does proper DC 14V appear at
Pin 1 of IC11? Check IC11.
Yes
No
Does proper DC 3.3 V appear at
Pin 3 of IC14? Check IC14.
Yes
Yes
No
Does proper DC 2.5 V appear at
Pin 4 of IC109 and IC17? Check IC109 and IC17.
No