Helló!
Skóppal mérve a csöveken egyforma jeleket mértem, de ellenállásmérővel pár ohmos különbség van a 2 trafó között. Volt már ilyen esetem amikor trafó okozta a hibát, de most nem vagyok benne biztos. Sztetek?
Köszi, üdv.: Ízirájder
The backlight in my old Acer monitor is only half-lit and there comes a 50 Hz buzzing sound from the inverter transformers.
The LCD image itself is fine.
What could it be, the CCFLs, the inverter or the power supply, does anyone know? Are the CCFLs OK?
Üdv Mindenkinek!
Van egy 24-es Acer monitorom, bekapcsolás után csak fehéren világít az egész kijelző. Mi okozhatja a hibát? Javítható lehet?
Előre is köszönöm a segítséget!
Hi,
I'm sorry for writing in English, but I don't understand any single word in Hungarian and I couldn't find an English subforum there.
I have changed the LVDS controller and now it's working perfectly, but I need help with the backlight. The CCFL lamps in the screen are OK. I connected the screen to another inverter (from BenQ T705, made on TL1451 which also has "protect" function) and the backlight worked perfectly. Again, I connected other screen to the malfunctioning ILPI-075 inverter and the screen also goes blank.
I changed all THT electrolytic capacitors on the board, but not much has changed. Before, the backlight was turning off almost immediately, now it glows for 1-2 seconds and then turns off.
The HV side of inverter transformers is about 470 ohm, they look OK.
I measured random capacitor in the +16V line, which is supplying the high voltage inverters.
We can see how the voltage went down while the backlight was powered on.
Also, the ON/OFF signal on ICL837's pin 8 is always present after powering up the power supply, even after the backlight turns off.
I don't have any idea what to check now..