Re: LG 32LE4500 LD01D - stays black no pic
After another test: I take out R157 , first resistor after IC101 , Resistor between PWM2 and PWM_DIM. 100 Ohm = OK. Without the resistor the PWM2 line has 3,2V. I think this a big Problem on the Mainboard or may it be another board?
Thanks...
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Re: LG 32LE4500 LD01D - stays black no pic
Hi, I will do a pic of the TV , I checked the error Signal, and it's right this Error Signal is the PWM Signal. Here are Voltages of the Invert Board, when I OPEN the Error Circuit (Inv Board to Mainboard)
PDim = Error : 6,4V
VDim = P.Dim: 4V
Ena = A.Dim: 3,6V
Det. = Inv ON: 0V
When I Close the Error Line now, only the PDIM Voltage drop down to 0. The other Lines are OK. On the other pic you see the real schematic as it is on board.
Thanks...
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Re: LG 32LE4500 LD01D - stays black no pic
Hi,
Q405 is full operating, I have test it after desoldering with an Transistor tester, it's in good condition, same as R421, R426, R425, R419. I have 3m3V on Collector, and 0,8V on Base of Q405
Error Out has 0V (pulled down to ground) , R486 is ok, an the 3,3V on R486 are also ok, but pulled down to ground.
Why can Error be pulled to ground on the power supply, when all the voltages are ok at the PS?
Best regards
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Re: LG 32LE4500 LD01D - stays black no pic
Hi yes I have the circuit Diagramm, When I pull out the Error ligne from the connector, and when I took out the base resistor of the Transistor, then the backlight light up, so the Inverter board is Ok. I think the Mainboard does not send the Inv_on LOW Signal (The Signal on the Base Transistor stays all the time 1V) and it keeps the Error ligne to gnd. So its the Mainboard I think. But what on Mainboard. Also soemthing strange is that the LED of the digital outport (Sound) doesn't light up, but all the voltages are ok on the board. Th...
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LG 32LE4500 LD01D - stays black no pic
Hello, The Tv Switches ok, Led turn from Red to White. Relais on power pcb = OK - Inverter stays out of order, Image black!
Voltages on Powerboard all Ok. 3,5V / 12V / 24V
Voltages from Mainboard to Powerboard:
P-Dim 3,4V
A-Dim 0V
Inv 0V
Error 0V
The main Inv Transistor on Mainboard is working.
What can I also try to find the fault?
Thanks?
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Re: LG 32LD550 no backlight stay in stby
Hi again, I have posted the schematics. I trace back to the IC1002 in the schematic. When I pull down PIN10 on the IC the backlight starts, so the Signal of the IC won't come down to the GND Level, so it's a Problem with the Startup process itselfs, this is causing the LED flashing all the time. Maybe you can help me when I give you the state of the Pin's of the IC1002:
Pin 1,2,3,4,6,8,10,11,12,13,15,16,17,18,19,20,21,22,23,25,26,29,36,39,40,48 = 3,5V
Pin 5,7,9,14,24,27,28,30,31,33,34,35,38,42,43,44,45,47 = GND
Pin 32,46...
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Re: LG 32LD550 no backlight stay in stby
Here's the schematic...
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Re: LG 32LD550 no backlight stay in stby
Hi, no he stack in standby or in boot up process. I don't think that there is a possibility to update the Firmware or is it? I've nothing find on the Internet
Many thanks
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Re: LG 32LD550 no backlight stay in stby
Hi,
I traced back the ON/OFF Signal on the Mainboard, because the backlight work when I shorten the ON/Off Pin on the Power Board with the 1k Ohm resistor. On the Mainboard there were 3 resistors, 1 Transistors, all are ok. Then I come to a Microcontroller "UPD78F0513AGB-GAF-AX". On pin 37 P1 is a high Output of 3,2V . This voltage don't Change when I put the TV on or back in Stby. So I think there must be a Major Problem on the Mainboard (microcontrollers or anything else) , so it's poor but I must Change the Mainboard....
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Re: LG 32LD550 no backlight stay in stby
Hi sorry Budm I think you were 2 seconds faster than me
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Re: LG 32LD550 no backlight stay in stby
Hi,
First I will check if it is the Signal of the Motherboard that is missing, how many voltage can i put on the Inv ON/OFF Pin to check if the backlights will start up?
Thanks
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Re: LG 32LD550 no backlight stay in stby
Hi together.
The caps are all checked, I solde them out (all) an checked the capacity an the ESR , all OK.
Here are the voltages first in Standby an second "switched on"
Error: 0 / 1,0
P-Dim: 0 / 1,0
A-Dim: 0 / 3,0
Inv On/Off: 0 / 0
3,5V: 3,5 / 3,5
20V: 0 / 21,4
12V: 0 / 12,6
Power On: 0 / 3,2
Many thanks
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Re: LG 32LD550 no backlight stay in stby
Hello,
Yes of course here are the Pictures:
Best regards...
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LG 32LD550 no backlight stay in stby
Hi everybody, I try to describe my Problem with an LG 32LD550.
When turning on the TV, the red Standby Led Begins red flashing. But that's all. No backlight, no Picture. I measured the voltage on the Power PCB . 20V OK / 12V OK / 3,5V OK . Power-On Voltage OK (5V) Only the INVERTER ON/OFF Pin stay at 0V. I checked up the 2 Inverter Transformer (seems OK) also the 4 Power MosFets of the Inverter an of course the fuse. Seems all OK. Does anybody have an idea? or maybe a schematic of this Power Board. His number is: EAX61124201/15.
Many thanks
Best regards
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