Sony Bravia Screen does not power on red light flashes 4 times: Difference between revisions

From Repair Wiki
(Created from migrating)
 
No edit summary
Line 1: Line 1:
{{Explanatory Guide|Device=Televisions/Monitor}}
{{Explanatory Guide|Device=Televisions/Monitors}}


== Problem description ==
== Problem description ==
Line 15: Line 15:
* Check all axial fans that have 3 wire leads. If the mainboard detects RPM of any fan is too low, it will trip as an overheat warning. Replace fans if necessary.
* Check all axial fans that have 3 wire leads. If the mainboard detects RPM of any fan is too low, it will trip as an overheat warning. Replace fans if necessary.
* On completion, reassemble case. Hold down Power button and Volume Down button and keep holding while you plug in the power cord. The light should flash green indicating a reset has completed successfully.
* On completion, reassemble case. Hold down Power button and Volume Down button and keep holding while you plug in the power cord. The light should flash green indicating a reset has completed successfully.
[[Category:Televisions/Monitors]]

Revision as of 21:59, 14 January 2024

Sony Bravia Screen does not power on red light flashes 4 times
Type
Device(s) Televisions/Monitors
Difficulty


Problem description

Screen does not power on, red light flashes 4 times.

Solution

This error is generally to do with protection related to overheating. Either the PSU is overloaded, the backlight power source/inverter is drawing too high a current, or a temperature sensor / related sensor has tripped.

  • Lie face down on a towel, remove bottom stand such that screen lies flat on towel.
  • Open rear and remove dust from PSU board. Careful any charged caps
  • If very dusty, remove PSU completely and dust with a brush (especially backside)
  • Ensure MOSFETs and diodes connected to heatsinks have thermal paste and are tightened accordingly.
  • Replace any swollen caps on PSU.
  • If it is a plasma backlight model, check the high-voltage connector plug between PSU and Inverter. Clean inside of plug ends with contact cleaner. Ensure cable is secure.
  • Check all axial fans that have 3 wire leads. If the mainboard detects RPM of any fan is too low, it will trip as an overheat warning. Replace fans if necessary.
  • On completion, reassemble case. Hold down Power button and Volume Down button and keep holding while you plug in the power cord. The light should flash green indicating a reset has completed successfully.