Re: Philips 47PFH4109 blinking 2 times when powering
Hello guys again. I managed to solve the backlight issue with this tv.
So i managed to take out the mosfet (in the datasheet is Q8104) and i figured out even though it was not shorted, but i couldnt open the fet with multimeter.
So I searched for a replacement and i found a random fet which had the same pinout. And it worked, lighted up the strip nicely. After i made sure that the mosfet is the problem i searched for a better replacement bc the random i found had 5ohm rds on resistance.
So i placed an IRF...
Protker
Member
Last Activity: 09-08-2022, 10:36 AM
Joined: 01-07-2020
Location: Horgos
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Re: Philips 47PFH4109 blinking 2 times when powering
Nope, with disconnected tcon remains the same.. I measuring the +30VDC before the step up converter, seems that maybe the converter chip doesnt doing its job properly (PF7903BS) Sadly i cannot find any kind of data of this chip, so i can temper maybe with the feedback leg or ovp leg, to make it work...Leave a comment:
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Re: Philips 47PFH4109 blinking 2 times when powering
So i tested out the capacitors, all showing the right parameters(what is written on the caps). I found the exact schematics on the net, and according to the schematics everythings is fine.
The problem is whenever i turn on the tv, it flashes 2 times(trying to light up the backlight), but unfortunatelly gives up and after these 2 try remains unlighted (i have screen logo etc btw)....Leave a comment:
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Re: Philips 47PFH4109 blinking 2 times when powering
I disassemled the whole tv took out the screen and applied dc to the strips.
I will try tomorrow to test the capacitors.Leave a comment:
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Re: Philips 47PFH4109 blinking 2 times when powering
So im back, i tested the leds, every led strip is lights up nicely. I assembled the tv back again. Im starting to suspect maybe a capacitor lost its capacitance, and causing the trouble here? Primarily the ones in nearest to the led connector?Leave a comment:
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Re: Philips 47PFH4109 blinking 2 times when powering
Thank you for all the comments and suggestions, i will tear down the tv as soon as i will have time for that, and will give you a feedback. Thanks!
Leave a comment:
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Re: Philips 47PFH4109 blinking 2 times when powering
So there is screen, only the backlight is missing.
I have to say i tried to light up the backlight applying dc on the led connectors and around 50V it lights up both led strip nicely. This is the reason im assuming the strips are good.
Maybe the supply board sensing that too much current was drawn by the strips and shuts off the backlight?Leave a comment:
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Re: Philips 47PFH4109 blinking 2 times when powering
Yes i get voltages on the mainboard. Well on the power supply board is written that there should be 12V, i get 11,3 11,7V, so i assume that is ok. After powering on i measuring voltages up to 50V on the led connector, then it falls back to steady 30V. After that no nothing stays in standby mode.
I should check if i get picture when its in standy mode no?
ThanksLeave a comment:
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Philips 47PFH4109 blinking 2 times when powering
Hello!
So i have a Philips 47PFH4109, and when i powering on the tv just blinks once, then after a 2 seconds blinks again, and does not turning on.
I mean i measuring voltages such like 30V on the leds and the 12 volts on the other panels, which seems to be okay.
I checked the backlight no issues with the leds.
I checked every component such as all the mosfets, all the diodes, i dont see any bad capacitors (unfortunatelly i only can measure up to 200uF).
I even took out the LD7591 chip and without it doing the same as before.
Im just seeking for advice,... -
Re: Samsung UN40D6400UFXZA Power Cycles
Hi! I decided so share my experience with this power cycling issue on a UN40D6400UFXZA Samsung led smart tv.
So i had a cycling issue with this tv, when i turned on the tv only a smart logo was shown for a half a sec and the tv was cycling to the eternity.
In my case was a faulty led. When i disassembled the tv, i found a single led on the strip, which is came off just by touch. So basically just shorted the led pads with a big solder blob and end of story. The tv working fine ever since.
But the most valuable hint...Leave a comment:
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