I have an RCA LED50B45RQ with the RE46HQ1290 power supply board. I am trying to get this tv working but I've hit a dead end. When i turn the power on, there is a quick white line that flashes across the screen followed by the backlights coming on and going right back off. After this i have to unplug the tv and plug it back in to get it to do this again. I've already done several voltage checks on various components of the power board, and I've found that there is a low voltage problem happening with the PFC system. The D4 rectifier diode was faulty, but upon replacing it I have the same issue. I found that if I unplug the LEDs from the main board and power the tv on, i can see the menu with a flashlight pointed at the screen. All of my voltages are listed below.
Filter Cap voltages are:
171.8v on EC1
171.4v on EC1A
My D4 rectifier diode reads 000 one direction and 461 the other direction.
L6599 IC voltages are as follows (TV powered ON):
CSS - 0V
DELAY - 0V
CF - 0.49V
RFmin - 0V
STBY - 0V
ISEN - 0V
LINE - 0.62V
DIS - 0V
PFC_STOP - 0V
GND - 0V
LVG - 0V
Vcc- 0.28V
N.C. - 0V
OUT - 0V
HVG - 0.22V spike, drops to 0V
VBOOT - 0.11V spike, drops to 0V
What could be causing these low voltages? I really would like to repair this board rather than buy a new one at the risk of somethin else being faulty.
Filter Cap voltages are:
171.8v on EC1
171.4v on EC1A
My D4 rectifier diode reads 000 one direction and 461 the other direction.
L6599 IC voltages are as follows (TV powered ON):
CSS - 0V
DELAY - 0V
CF - 0.49V
RFmin - 0V
STBY - 0V
ISEN - 0V
LINE - 0.62V
DIS - 0V
PFC_STOP - 0V
GND - 0V
LVG - 0V
Vcc- 0.28V
N.C. - 0V
OUT - 0V
HVG - 0.22V spike, drops to 0V
VBOOT - 0.11V spike, drops to 0V
What could be causing these low voltages? I really would like to repair this board rather than buy a new one at the risk of somethin else being faulty.
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