My tv model is lg 55ub850v and the backlight s totally off. My psu got 5 led light flashing and measured p211+p210 and the 28 pins port on psu and the 24 pins port on mainboard, it had 47v, 3.5v and 12v+24v when pushed the button to turn on tv but the voltage on f2 fuse of t con s only 0.895v.
LG55UB850V no backlight
Collapse
X
Related Topics
Collapse
-
by DanPokaI 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...-
Channel: Troubleshooting Computer Displays
-
-
by Comp_ProHello all,
Am trying to figure out this backlight issue with this A1990 Macbook Pro.
Tests performed:
There is no backlight even with a good screen.
Backlight IC is receiving the correct support voltages.
Fuse F8400 ok
Current sense resistor R8400 ok
Backlight IC is receiving 3.3V on enable pin.
Backlight IC receiving voltage from PPBUS_G3H, aprox 12.5V.
Backlight IC receiving 5V from PP5V_G3S
Backlight IC BKLT_SCL and BKLT_SDA both measure 0.545V diode mode to ground
I2C_BKLT_SCL and I2C_BKLT_SDA both measure... -
by cheebsterHello, 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... -
by canadaboy25Hi 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...-
Channel: Troubleshooting Computer Displays
-
-
by SS454vizio e650i-a2 (LWJAOZBP Serial) led backlight flashes then turns off, has video (via flashlight) and audio.
panel: au optronics T650HVN05.4
72 led total on 12 strips, 6 led per strip wired in three groups of 24 (led driver board has three anode and three cathode pins)
link to datasheet: https://datasheetspdf.com/pdf-file/8.../T650HVN05.4/1
Vizio 56.04219.641G (liteon PA-3231-01WN-LF) Power Supply Unit
https://www.shopjimmy.com/vizio-56-0...-power-supply/
Vizio 55.75J01.001G (91.75J10.004G) Main Board... - Loading...
- No more items.
Comment