I inserted a board from the A2159 into a Mac A2189 and connected the display. Before I did that, the MACBook A2159 worked perfectly. Now there is no more picture! I have no more 46V on the C84 ..... only 12V. I read you should be careful about the video board. Unfortunately too late! Is the U8400 now defective or what can be defective? Thank you for the help.
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Re: A2159 No Backlight just 12V not 46V
Not in front of my schematic database but does the lcd work?
Shine a flashlight in front of the screen while it is on. Can you the desktop icons, graphics? -
Re: A2159 No Backlight just 12V not 46V
hi, no its dark. i have just 12Volts at the Capacitor line C84.... not 46VComment
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Re: A2159 No Backlight just 12V not 46V
1) C84 ? Confirm the full cap # - unable to find this capacitor.
2) Voltage on F8400, pin # 2 ?
3) voltage of PP5V_S0SW_LCD ?
4) voltage of PPVOUT_S0_LCDBKLT ?Comment
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Re: A2159 No Backlight just 12V not 46V
C8460, C8461, C8462... I will look. THXComment
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this tv is throwing me for a loop. do samsung tvs no longer have the backlight self test feature built into the power supply?
i tested the backlight with my LED tester and it lights up both strips. one of them reads 100v and the other reads 63.7v.
unplugged mainboard from power supply but left backlight plugged in, and then plugged psu wall power in. expected to see backlights light up but see nothing.
according to how ive diagnosed in the past, this would almost always be a bad power supply. replacement power supply was cheap like 20$ from ebay. but still i get not even... -
I bought this p2210f dell monitor to fix. Schematic is the same as p2210.
Behaviour is that monitors comes on but then backlight switches off almost instantly. If I look with flashlight I can still find the "No signal message". So definitely a backlight issue. Trying to advance the issue I proved that the protection circuit is switching off the backlight by shorting out C3 and resistor to disable the INL chip then re enable by removing the short.
This is where it gets interesting. When I disassembled the monitor to solder leads on c3 capacitor I noticed the backlight flickered... -
Hello, got an iPad Pro A2378 12.9 5th gen with no backlight. Got another test unit without screen, tested the screen, still no backlight with the test unit.
Figured out the backlight on the screen was bad, ordred a new backlight from mobilesentrix, *carefully replaced it* without damaging the lcd, oh well.
Final result, issue is still there, the screen has no back lights. So i'm back to square one, with 3 hours less and 100$ out, issue still on the screen.
The panel is still ok, i can see the apple in the middle of the screen when it kicks in, just no backlight.
Anyone... -
I have MacBook Pro A2159 EMC 3301 board 820-01598 that Touch bar is working but with No Backlight, I replaced it with a new one , have the same issue
Checked both connecters J5110 , J5100 from board side and from Touchbar side , it have no issue
so if anyone know how to make sure backlight voltage is exist , and which pin? -
Hi all,
I've got an LG Flatron 24EN33TA with a backlight issue. The problem began with the monitor not powering up after sitting for a long time (overnight or during the day throughout work). When I would wake the computer up, the backlight would flick on for a second then go out. Sometimes it would take many tries to get it to come on. Once the monitor came on, it worked flawlessly until another long duration of being powered off.
I thought the problem would be bad caps but I checked both of the caps on the board and they are fine. I also tried powering the monitor from...
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