Lg flatron w2252tq-pf

[fuxxy]

Re: Lg flatron w2252tq-pf

Correct, my display is exhibiting the same symptoms as your monitor, However it's an identical LCD panel in a TV package instead of computer display.

[s_henya]

Re: Lg flatron w2252tq-pf

you have the same problems as i had?

i tried my best but found no solution but replacing the panel,

to your question, the tcon board is connected to the panel with ribbon cables that are

glued/soldiered on the board that cannot be opened.

[fuxxy]

Re: Lg flatron w2252tq-pf

So, in short:

"Blurriness" and distortion were caused by bad TCON, on this model LCD panel the TCON is not replacable?

The same panel is used in my defective device, an LG TV, 22LG30

[s_henya]

Re: Lg flatron w2252tq-pf

i got a replacment panel yesterday, found a screen with broken logic board

and now the image is perfect.

good thing i havent tossed it away.

[s_henya]

Re: Lg flatron w2252tq-pf

the missing voltage on the pin2 of Q1 is ground, sorry didnt check that sooner,

voltage testing on lvds connector on the tcon board:

PIN VOLTAGE
1 GROUND
2 1.1
3 1.1
4 1.1
5 1.1
6 1.1
7 1.1
8 GROUND
9 1.1
10 1.1
11 1.1
12 1.1
13 1.1
14 1.1
15 GROUND
16 1.1
17 1.1
18 GROUND
19 1.1
20 1.1
21 1.1
22 1.1
23 1.1
24 1.1
25 GROUND
26 3.3
27 3.3
28 1.6
29 4.9
30 4.9
31 4.9
32 GROUND

taken from the tcon specs:

Pin No Symbol Description

1 RXO0- Minus signal of 1st channel 0 (LVDS)
2 RXO0+ Plus signal of 1st channel 0 (LVDS)
3 RXO1- Minus signal of 1st channel 1 (LVDS)
4 RXO1+ Plus signal of 1st channel 1 (LVDS)
5 RXO2- Minus signal of 1st channel 2 (LVDS)
6 RXO2+ Plus signal of 1st channel 2 (LVDS)
7 GND Ground
8 RXOCRXOC+ Minus signal of 1st clock channel (LVDS)
9 RXO3- Plus signal of 1st clock channel (LVDS)
10 RXO3+ Minus signal of 1st channel 3 (LVDS)
11 RXE0- Plus signal of 1st channel 3 (LVDS)
12 RXE0+ Minus signal of 2nd channel 0 (LVDS)
13 GND Plus signal of 2nd channel 0 (LVDS)
14 RXE1- Ground
15 RXE1+ Minus signal of 2nd channel 1 (LVDS)
16 GND Plus signal of 2nd channel 1 (LVDS)
17 RXE2- Ground
18 RXE2+ Minus signal of 2nd channel 2 (LVDS)
19 RXECRXEC+ Plus signal of 2nd channel 2 (LVDS)
20 RXE3- Minus signal of 2nd clock channel (LVDS)
21 RXE3+ Plus signal of 2nd clock channel (LVDS)
22 GND Minus signal of 2nd channel 3 (LVDS)
23 NC Plus signal of 2nd channel 3 (LVDS)
24 NC Ground
25 PWM_OUT No Connection (For LCD internal use only.)
26 VLCD No Connection (For LCD internal use only.)
27 VLCD Reference signal for burst frequency inverter control
28 VLCD Power Supply (5.0V)
29 RXO0- Power Supply (5.0V)
30 RXO0+ Power Supply (5.0V)

if no other ideas will come up i'll give up on this monitor
repair too much time and effort,

BUT i'm not regreting i've learned a lot!!

[selldoor]

Re: Lg flatron w2252tq-pf

Doesnt matter what you use- not too hot though and not near the bonded cables at the top in case the bonding melts and makes it even worse.

[s_henya]

Re: Lg flatron w2252tq-pf

good idea, should i use hot air from the rework station, or hairdryer?

which temp should i pick?

i will do some voltage testing on the lvds connector, maybe the connector itself is defective

i will update tonight or tommorow.

thanks again selldoor, i feel i already learned a lot more out of this monitor repair.

[selldoor]

Re: Lg flatron w2252tq-pf

Really need help from members who understand Tcons. In the meantime try and and do as many measurments as possible - there are lots of test points like VCC+5V, VDD, VGL, VGH, SDRAM_VDD, VLS, 3V, SSC_VDD, D-VDD, and S_VDD(?) and a cluster on the right hand side of the board near the Q1 & Q2 Vcomp VSTR GRES DISC GVDD-E GVDD-O and so on. The results may mean something to somebody.
Could also try warming the tcon with a hairdryer and see if it sorts itself out quicker, then try and pin it down to a part of the board by just heating sections. Sadly may turn out to be a fault within the panel

[s_henya]

Re: Lg flatron w2252tq-pf

sorry for not updating on voltage testing,
the voltages are pretty constant,

i tried the power supply and power board with the samsung lvds cable
on the lg screen and the picture was bad,
tried all the lg parts on the samsung screen and the picture was perfect so the problem is either the lvds connector on the tcon board or some other ic chip. the Q is very likely, i dont know a good substitute.

[selldoor]

Re: Lg flatron w2252tq-pf

Well that quite bad news. Can you try the known to be good lvds cable on the LG panel or is it different.

"the tcon is attached with ribbon cables to the screen and i dont think it could be replaced."

Unfortunately Correct.

Were you able to do the Q1 and Q2 test when cold and when warm as Budm suggested.

[s_henya]

Re: Lg flatron w2252tq-pf

got a 20.5 samsung with a little crack,

plugged the cracked screen to the power supply and logic board of the lg

and the picture is perfect,

plugged the samsung power supply and logic board and the image is even more

scrambeled,

so the tcon board a bad for sure,

i need some instructions for fixing it if even possible,

could be a bad ic or lvds connector?

the tcon is attached with ribbon cables to the screen and i dont think it could be replaced.

[selldoor]

Re: Lg flatron w2252tq-pf

Read the pdf - none the wiser.
Still failing to find Q1 and Q2. How difficult would it be to measure that 0.05 pin as it was going through its stripey startup? Also can you measure the 5v test point near U5 as its going through startup to see if it fluctuates.

[selldoor]

Re: Lg flatron w2252tq-pf

Sorry my error - meant the power supply board - whilst I know you say it works fine in with the 19" screen I just wonder if it need a bit more "umph" to drive the 22"
I Think it is just 5 caps and I see people sell cap kits for that model so it is a sign that
the caps need replacing often else they wouldnt sell the kits. I am going out now so
will look at your attachment later.

[s_henya]

Re: Lg flatron w2252tq-pf

if you mean the logic board already recapped it with fresh caps
no change at all, the psu inverter board is another thing :-)

btw the only info i found about the tcon was this, not very helpful...

[selldoor]

Re: Lg flatron w2252tq-pf

Hi - Good at least thats the half dull sorted. I will continue to try and find what the Qs are
in the meantime I would upgrade the caps on the main board.
The pressing point was an alternative fix for the dull half so i think you can forget that,

[s_henya]

Re: Lg flatron w2252tq-pf

the tcon model: LM220WE1-TLE1
i've added 4 more pics it goes from left to right
where do you want me to press?

[s_henya]

Re: Lg flatron w2252tq-pf

selldor your guide helped a bit, thank you

the half screen was a function :-)

but there a still some strips on power on and little lines on the screen,

im going to investigate some more tommorow and update as soon as possible

and add some more pictures

[selldoor]

Re: Lg flatron w2252tq-pf

Hi been trying to track down your ICs but failed - what is the Tcon board number. I dont think you put up a picture yet?
Also my ramblings in post 25 did have a point but I didint make it. I was going to suggest that whilst it was on - half and half you try pressing on the panel cable at the socket. ( Same effect as my packing it)
The next bit about the engine also is based on a fact the engine button has a
shop/ display mode.
Here is the handbook
http://www.manualowl.com/m/LG/W2252TQ-TF/Manual/54624
Its on page 17A

[s_henya]

Re: Lg flatron w2252tq-pf

hey budm,

the voltages are pretty constant no matter cold or warm start.

the 0.05 volt is my guess,

i dont really know how tcon board works.

but one transistor is good and one side of the picture is good and the other bad,

if i knew what type of transistor is it i would order one or two and replace,
but i cant read clearly as you can see...

[budm]

Re: Lg flatron w2252tq-pf

Do the readings on Q1 and Q2 change when it is cold and after warm up?