lcd tv 22ld350-za

[vitvel]

Hi , can anyone send me a message to help me fix this LCD TV , because after turning it on, the picture disappears after 20 seconds and the red LED starts flashing. Any ideas? Thanks!

[Andrew F. Ali]

Re: lcd tv 22ld350-za

Share with us Make and Model of your TV and Clear Pictures of the back of the TV with the covers removed. Also clear pictures of the connectors to and from each board so we could see voltages expected at each pin of the connectors.

[vitvel]

Re: lcd tv LG 22ld350-za

Share with us Make and Model of your TV and Clear Pictures of the back of the TV with the covers removed. Also clear pictures of the connectors to and from each board so we could see voltages expected at each pin of the connectors.

Excuse me I have a little bit problem to edit attachments and how to put the photos

[dick_barton]

Re: lcd tv 22ld350-za

Can you take the voltage readings when you first switch on and then when you lose the picture at the connector highlighted and give the names of the pins.

[vitvel]

Re:LG lcd tv 22ld350-za

Conn P201 on PSU at Stby : 1,2 to Gnd shoud be 15 VDC , measure =16,03V
3,4 = Gnd
5, 6 3,5 V , meas =3,41V
7 = Gnd
8 = OLP meas =0 V
9 = EN m =0 V
10 = BD ( M ) = 0,11V
11 = AD ( M ) = 0 V
12 = NC
At ON ( picture exist ) : 1, 2 to Gnd....................................=14.7V
5,6 ................................... = 3.45 V
8 .................................. = 0V
9 ................................. =0V
10 fluctuation 3,27 ; 2.51 ;0 V ( 3 X )
11 fl. 3,24 ; 1,71 ; 0,15V(3x)

When red LED flashes 1,2 fluct. from 15,75 to 15,85 V
6,7 ...................................= 3,4 V
10 ..................................= 0,11 V
11 ..................................= 0,15 V

I saw backlight becomes black 3 times - when voltage on terminal 10 and 11 fluctuated to 0 V.
All of this within 20 sec.

[budm]

Re: lcd tv 22ld350-za

Are you sure that when the backligts are on and you see the images on the the screen, the EN pin stays low? That EN pin is the BL-ON control signal.
BTW, the power supply is an always on power supply and it is OK.

9 = EN m =0 V. EN = BL-ON
10 = BD ( M ) = 0,11V. BD = PWM dimming control.
11 = AD ( M ) = 0 V. AD = Analog Dimming control.

[vitvel]

Re: lcd tv 22ld350-za

Hi budm , you are right , signal EN ( P201/9 ) at Stby = 0V , at ON ( when image exist ) = 3.3V , and drops to 0V 3 times within 20 sec and backlight become dark.Then , red LED fleshes and EN = oV

[budm]

Re: lcd tv 22ld350-za

It sounds like it may have gone into standby due to no video signal form PC.
Do you have it connected to a running PC?

[vitvel]

Re: lcd tv 22ld350-za

Can i upload video clip 25 sec duration , where is showing from picture appeared , 3 times darkness then short time picture and constant darkness with red LED flashes,connected to PC. I think there are some protective mode , but I cant discover causes.I changed 3 elco on PSU on 15 V line for invertor but no effect.

[vitvel]

Re: lcd tv 22ld350-za

Can i upload video clip 25 sec duration , where is showing from picture appeared , 3 times darkness then short time picture and constant darkness with red LED flashes,connected to PC. I think there are some protective mode , but I cant discover causes.I changed 3 elco on PSU on 15 V line for invertor but no effect.