LED TV Randomly Can’t Power On, Randomly Power Shutdown and Randomly No Display
Model: Hisense LED40K16X3D, LED40K11P, LED40K16P, LED42T39AK, LED42K100, LED42K200,
LED42K300,
LED42H310,
LED46K01P,
LED46T39AK,
LED37K01,
LED37K11,
LED37K16、LED50K660X3D,
LED50EC660X3D,
LED55T36GP,
TLM37E29,
TLM37V68,
TLM37V88P,
TLM40V66PK,
TLM40V68P,
TLM40V68PK,
TLM40V69P,
TLM42V67PK,
TLM42V68PK,
TLM42V86PK,
TLM42P69GP,
TLM42E58P…
Related PSU
board: (RSAG7.820.4162) 4162, 5024, 2289,
1673, 1185, 1901& etc.
Symptom:
The
TV randomly can’t power on TV, or randomly power shutdown, or randomly no display, or when the TV long time in
standby mode, it can’t use the remote controller to control power on TV. But power off the TV and then power on
TV back, the remote controller can control the TV now.
Cause:
All
these symptom are causing by the PFC voltage output drop below 370V, typically when occur the above symptoms
their PFC output voltage is about 340V~ 360V or below 370V. What will cause the PFC output voltage drop?
Actually they are many reasons, but in this case, it is because of their PFC IC pin-1 VFB (Voltage Feedback)
sampling circuit line corresponding component/s leakage. Especially their voltage divider resistors are a common
fault of this strange problem in TV power supply (PSU). It is because of these divider resistors leakages and it
is causing by the red glue (Seal Glo) under these SMD resistor. For example the RSAG.7.820.1673 PSU board
(normally call it as 1673 board), their divider resistors R823, R824 & R825 are inside the PFC section as
photos below:
Repair/Solution:
Removed these divider resistors,
cleaning their PCB board red glue and also the red glue attached on the bottom of SMD resistor. After clean all
these red glue from the above divider resistors (R823, R824 & R825) and solder it back to their appropriate
location. Finally this type of strange problems in LED TV was solved. Remember, not all the above PSU board
their divider resistor is same these R823~R825, may be different part number of PSU board will vary. But their
reason is same, is because of the PFC IC pin Voltage Feedback sampling circuit line component/s was leakage and
caused these strange problem occur.
2016 New Ebook on How to Troubleshooting
& Repairing LCD/LED Screen Panel :
LCD/LED Screen Panel Repair
Guide
|