Troubleshooting Lt-22Xx Power Troubleshooting - Mitsubishi Electric LT-2220 Service Manual

MODELS: LT-2220 / LT-2240 / LT-3020 / LT-3040 / LT-3050
1. Power failure
1.1 In case of LT-22XX
(1)POWER is turned off.
Connect the Power plug and turn on the main Power switch (Front switch or remote control).
Is the POWER LED lit?
YES
· To "Flashing in green"(2)
· To "Flashing in amber"(3)
NO
Is the power plug connected
to the wall outlet correctly?
YES
Is all harness connected
correctly?
YES
Is the 20V DC available before
the fuse F800?
(Observing point : J801)
* Voltage range of 20V :18~21V
YES
Is 20V DC available behind
the fuse F800?
(Observing point : J802)
* Voltage range of 20V :18~21V
YES
Is the S5V and S3.3V, AD3.3V output
available at Pin12(S5V) and Pin13
(S3.3V) of J303 and at Pin6 of J190
(PH connector)?
CN
S5V J303
S3.3V J303
AD3.3V J190
YES
IC300 and peripheral circuits
are out of order.(PWB-MAIN)
NO
Poor power plug connection.
NO
All harness connects
correctly.
NO
The AC-ADAPTOR is out of
order.
NO
Fuse F800 have blown out. If
the fuse are replaced and it
blows out again, the AC-
ADAPTOR is out of order.
NO
Pin No. Voltage
12 5Vdc
13 3.3Vdc
6 3.3Vdc
Power supply circuit
which generates S5V
and S3V and AD3.3V in
the PWB-SUB(SET) is
out of order.