LG W2241S white screen symptom

[emta41]

Dear,
my LG W2241S has a white screen symptom. Ive checked power board, logic board, panel board and T-con, without success. Do You have any experience or hints? Thank Zou in advance.

[Nocta]

Re: LG W2241S white screen symptom

Recap the logic board and check the ribbon cable. Sometimes, if the ribbon cable is connected the other way, it can cause a white screen.

[emta41]

Re: LG W2241S white screen symptom

Ive attached images of PWR, logic and panel board. Caps on logic board looks ok. Ive tried change PWR PCB+logic PCB+cable from similar type LG monitor, where is no white screen symptom. Without success.
It looks as panel board problem, but where or how to find it?

Thank You in advance.

[Duncanbest]

Re: LG W2241S white screen symptom

Ive attached images of PWR, logic and panel board. Caps on logic board looks ok. Ive tried change PWR PCB+logic PCB+cable from similar type LG monitor, where is no white screen symptom. Without success.
It looks as panel board problem, but where or how to find it?

Thank You in advance.

1.Assemble all board as original.
2.power on,
a.check testpoint TP129 voltage (the voltage from AD board =5V)
b.check testpoints VDDG VDDA VEEG VDDD voltage
29.5V 13.0V -6.5V 3.3V
3.If testpoint voltage is fail ,then check the panel
IC502 regulator as pic.
(top pin input=5V middle pin output=3V bottom pin =GND )

PS:It is hard to check the IC502's voltage because of the panel's weak FPC.
I solder a wire at middle pin ,then assemble all board , power on ,check voltage.
That's my experience and change the NG IC502 ,monitor works again.

[emta41]

Re: LG W2241S white screen symptom

Thank You, I will test it.

[emta41]

Re: LG W2241S white screen symptom

Dear Duncanbest,
what is the function of IC502 and where can I found the replacement? Ive found the FitiPower FP8805-33, but there is no datasheet.

[Duncanbest]

Re: LG W2241S white screen symptom

It's a regulator with fix 3.3V output (check #4 ,I input the wrong voltage value)

I use a LDO SOT223 to replace . But I forgot the exactly part number.

Maybe LD1117A or AIC1117-3.3 ,there are too many LDOs with the same function.

Package SOT223 with in-out-GND (like pic. top to bottom) @1000mA LDO

[budm]

Re: LG W2241S white screen symptom

Just generic 1117-3.3V series. I.E.
http://www.digikey.com/product-detai...ICT-ND/2095612

[emta41]

Re: LG W2241S white screen symptom


Thank You very much! The replacement of IC502 was helped.
The LCD works again!!!

[budm]

Re: LG W2241S white screen symptom

Great news, so what voltage did you get from the old 3.3V bad regulator?

[emta41]

Re: LG W2241S white screen symptom

So, Ive used LD1117AS33TR for replacement. The measured voltage on old FitiPower FP8805-33 was 2V. But it is not so easy to measure it, as said Duncanbest...

[spyroslo]

Re: LG W2241S white screen symptom

hi i don't have the VEEG (-6,5v ) any idea for this

thnx