Troubleshooting Flowchart - Toshiba TP43H60 Service Training

Troubleshooting Flowchart

Caution:
Before removing or adding
fuses, remove all power from
the television and always use
an Isolation transformer when
troubleshooting.
Connect a 100W light
bulb between the power
supply side of F470 and
isolated Ground. Check
the voltage across it.
Remove light bulb and put
F470 back in circuit.
Check Q370's
Collector with a
Peak-response meter.
Check +125V
Protect, and
(Section three)
Start
Remove fuse
F470.
Apply
power to the TV.
No
Does it still
shutdown?
Yes
voltage regulate
collector voltage go
No
to or above 9V?
OCP , X-ray
+200V UVP .
Yes
-18V
Does the
at +125V?
Does
Q370's peak
Check
25
Notes:
This flow chart is to help isolate
the cause of shutdown. Refer
to the circuit explanations for
additional information.
With F470 open, the power
LED blinks whether the
television is in shutdown or not.
The indication of shutdown is
the relay disengaging after
closing, and the power must be
removed and restored to the
TV to re-engage the relay.
Key:
OVP = Over Voltage Protect
OCP = Over Current Protect
UVP = Under Voltage Protect
Check the +18V OCP
OCP and + 36V OCP
(Section one)
No
Check the main power
supply.
Yes
+35V OCP , +9V UVP
and +35V UVP
(Section two)