• LG W2242T podświetlenie gaśnie

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LG W2242T podświetlenie gaśnie

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#1 LG W2242T podświetlenie gaśnie

by schekris • 20 November 2019, 17:12
Witam,
Mam dokladnie ten sam problem co w tym wątku.
lg-w2242t-podswietlenie-gasnie-t19951-20.html
Płyta to eax40312104/2
Zatrzymałem się na temacie zdjęcia diody d303 i d302 wtedy rzeczywiście monitor zaczyna działać, po wlutowaniu D302 usterka występuje dalej. Gdzie moge szukać przyczyny?

Re: LG W2242T podświetlenie gaśnie

by Google Adsense [BOT] • 20 November 2019, 17:12

#2 Re: LG W2242T podświetlenie gaśnie

by matic • 20 November 2019, 20:29
Hello!

Measure the resistance between listed points:
a) Between points "A" and "B".
b) Between points "C" and "D".

Image

#3 Re: LG W2242T podświetlenie gaśnie

by Vogelek23 • 21 November 2019, 01:16
Dodatkowo, proszę zmierzyć rezystancje do masy na katodach D302 i D303 (diody ZAMONTOWANE na czas pomiaru).

#4 Re: LG W2242T podświetlenie gaśnie

by schekris • 21 November 2019, 13:02
Measure the resistance between listed points:
a) Between points "A" and "B". - 1kΩ
b) Between points "C" and "D". -1kΩ

rezystancje do masy na katodach D302 i D303 (diody ZAMONTOWANE na czas pomiaru). Jednakowo 96kΩ

#5 Re: LG W2242T podświetlenie gaśnie

by matic • 21 November 2019, 19:13
Switch the cables of backlight lamps as follows:
a) Cable from connector P401 connect to P404.
b) Cable from connector P404 connect to P401.
c) Cable from connector P402 connect to P403.
d) Cable from connector P403 connect to P402.

After that check, if the monitor still works without diode D302.
If you are not able to connect the LCD matrix video connector in this case you can test it without it (in this case there will be no picture on the screen, but the backlight should work).

#6 Re: LG W2242T podświetlenie gaśnie

by schekris • 22 November 2019, 12:00
After changing the wires and desoldering the d302 diode, the backlight works.

#7 Re: LG W2242T podświetlenie gaśnie

by matic • 22 November 2019, 19:27
schekris wrote:After changing the wires and desoldering the d302 diode, the backlight works.
Ok, how is it in the original state? If I understood you correctly it is exactly the same (backlight works without diode D302)?

#8 Re: LG W2242T podświetlenie gaśnie

by schekris • 25 November 2019, 12:07
Po zamianie złącz do świetlówek i wylutowaniu diody podświetlenie działa, po wlutowaniu diody brak podświetlenia. nieważne jest to czy są zamienione złącza świetlówek czy też nie

#9 Re: LG W2242T podświetlenie gaśnie

by Usunięty Użytkownik 576 • 25 November 2019, 15:59
Ta dioda to wyłączenie zabezpieczenia.Gaśnie ci podświetlenie bo któraś ze świetlówek ma za duży prąd ,jest wypalona lub wypalone połączenie przy samej świetlówce.Stawiam na dwie górne.Polecam przerobić na ledy .Zestawy sterownik i ledy na all...o.Przerobiłem kilkadziesiąt szt tv i monitorów do 32 cali.

#10 Re: LG W2242T podświetlenie gaśnie

by matic • 25 November 2019, 20:15
schekris wrote:Po zamianie złącz do świetlówek i wylutowaniu diody podświetlenie działa, po wlutowaniu diody brak podświetlenia. nieważne jest to czy są zamienione złącza świetlówek czy też nie
According to that it seems the issue is related to the protection circuit or lamp driver circuit on the board, not the CCFL lamps.

The issue is probably related to one of the following components: R302, R401, R403, R405, C401, C402, C403, C405, C408, C411, C415, D401, D403.
First check the solder joints on all listed components.

Re: LG W2242T podświetlenie gaśnie

by Google Adsense [BOT] • 25 November 2019, 20:15
 This topic is marked as ARCHIVAL. Please only reply if your message contains the solution (Terms and Conditions p. 12.1).
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