Re: TV Phillips 42PFL4307H/12 power supply with LED driver problem
What I want to say in other words that I think the problem is very likely in the main board itself, because BL_ON has to become from here (specifically from standby controller PNX85500)......
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Re: TV Phillips 42PFL4307H/12 power supply with LED driver problem
Sorry but I understand this chart obviously wrong to pull pin BL-ON to HIGH (3.3V) by myself to start-up power supply and get reference voltage 5.96V at pin 25 on LED driver (U401).
As I see these 4 inputs are from the main board and other outputs are from the power supply unit:
2 - Standby,
11 - BL-ON-OFF,
12 - BL-DIM(Vsync),
13 - BL-I-CTRL....Last edited by darkoan; 05-02-2017, 01:44 AM.
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Re: TV Phillips 42PFL4307H/12 power supply with LED driver problem
I put power supply unit back to TV and I hear high frequency noise on large transformer which seems to me like at normal operation.
+12V line is on for around 40 seconds than stops for 3 seconds and the cycle is repeating and it looks like enable some sort of protection circuit.
Now with PSU inside TV signal BL-I-CTRL is 3.6V and BL-ON is not changing just a couple of millivolts.Last edited by darkoan; 03-09-2017, 02:07 AM.
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Re: TV Phillips 42PFL4307H/12 power supply with LED driver problem
Sorry guys to make such a confusion here budm was right... (Thanks budm for make this things clear now.)
I am able to turn power supply on with GND and STANDBY pins and get right value from PFC on the main filter cap around 325V to 390V.
And voltages on connector 1M95:
3V3stdby = 3.3V
Standby = 2.6V and go low (as expected)
+12V = 12.32V
Vsnd = 12.32V
BL-ON = 0V
BL-DIMM(Vsync) = 0V
BL-I-CTRL= 7.64V
POK = 0V
And on connector 1M11:
+12V_AL...
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Re: TV Phillips 42PFL4307H/12 power supply with LED driver problem
Thanks for your replays.
I put 3.3V to STBY pin through a 1k resistor and nothing happened, no Vcc.
Can I measure some voltage on optocouplers PC101 and PC102 close to Q101 and Q301?
I only get +1.06V on diode side of PC101 optocoupler...
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TV Phillips 42PFL4307H/12 power supply with LED driver problem
Hi everyone
I am trying to repair LED LCD Phillips 42PFL4307H/12 with PSU problem. I already replace suggested components U101 FSL106HR integrated high voltage PWM switch and U501 L6599 high voltage resonant converter and also Q581 STK0160 with no luck.
I measure output voltages and I have only two outputs:
3V3stdby = 3.3V
Standby = 2.6V
+12V = 0V
+Vsnd = 0V
I check voltage at main filter cap C646 and I only have steady 320V and not 380V ~ 400V as I expect from PFC stage.
Also Vcc voltage is missing and no Vcc to U601 SCY99102BDR2G...
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Re: New Members - please post your introductions here
Hello I am electrical engineer and in my spare time when I came back from daily job I like to repair electronics stuff like computers, laptops, TVs,...
At this time I would like to repair power supply unit of Phillips LCD LED TV 42".
And wish me good luck.
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