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Crumbtrail TV Forums: TV Equipment: LCD TV Forum:
Hello.

 

 


danielsoy
New User

Jun 25, 2014, 2:03 AM

Post #1 of 15 (2003 views)
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Hello. Can't Post

Hi ppl, this is my first post.

Would like to know if i may ask a question about
a LCD PC monitor (not tv) repair.

Thanks.



jts1957
Veteran


Jun 25, 2014, 2:49 AM

Post #2 of 15 (2000 views)
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Re: [danielsoy] Hello. [In reply to] Can't Post

Sure. Why not?


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Location: Far, Far Away


danielsoy
New User

Jun 25, 2014, 11:02 PM

Post #3 of 15 (1985 views)
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Re: [jts1957] Hello. [In reply to] Can't Post

Ok , thanks JTS.

This is a Samsung monitor SyncMaster 2233 that shows frozen video of a moving image by just a second, and then goes dim.
So I can see just a frame by a second, when i watch a movie for instance, then the screen stays white, but image fades away and don’t return.

When i turn monitor off, and then on again, or if I change PC video output, from internal to external , get the same effect .A frame that last a bit, and fades.Like this:

https://www.youtube.com/watch?v=8ZGTuNltrnA


I cleaned up a cockroaches nest over the main board ,that was a lil rusty.

Power supply voltages, are ok and without ripple .X-tal is oscillating
at 12mhz.

Is it possible, by connecting my scope to the main board output that goes to de LCD flexible wire, to confirm if is the LCD panel, or the main board the part at fault?


jts1957
Veteran


Jun 25, 2014, 11:40 PM

Post #4 of 15 (1983 views)
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Re: [danielsoy] Hello. [In reply to] Can't Post

It's also upside down.
Computer is set to output the correct display parameters/resolution?
Does it do this on DVI & 15pin?
Does Self-Check feature work properly?

Do you have the Service literature?


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Location: Far, Far Away

(This post was edited by jts1957 on Jun 25, 2014, 11:59 PM)


danielsoy
New User

Jun 26, 2014, 2:24 AM

Post #5 of 15 (1975 views)
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Re: [jts1957] Hello. [In reply to] Can't Post

It was easier take the video with monitor upside down, cause monitor was opened in that position ,but image its not inverted indeed.

Screen config is ok.

Input is VGA(theres no DVI).I have Hsync ,Vsync And video input on that connector and in the microprocessor pins.

Did not try to access to service mode .

Got service manual of another monitor similar to this one.

I can see something like a video signal at 60hz, on the flex wire connector pins that goes to the LCD panel.
And setting scope to 20nsec, there is something like a clock on the clkm and clkp outputs.

Service manual says that LCD panel is broken, but Iīm not sure...


Video n clock signals oscillogram is uploading.


https://www.youtube.com/...amp;feature=youtu.be


jts1957
Veteran


Jun 26, 2014, 3:34 AM

Post #6 of 15 (1973 views)
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Re: [danielsoy] Hello. [In reply to] Can't Post

What is full model number?
What is similar Service manual number?

Scaler PCB is at one end of the LVDS cable, the other end usually plugs into a PCB that is part of the TFT display. There is sometimes a small surface mount fuse for 5V line on this board that opens.

from User Manual ...
Self-Test Feature Check:
1. Turn off both your computer and the monitor.
2. Unplug the video cable from the back of the computer.
3. Turn on the monitor.
If the monitor is functioning properly, you will see a box in the illustration below.
This box appears during normal operation if the video cable becomes disconnected or
damaged.
4. Turn off your monitor and reconnect the video cable; then turn on both your computer
and the monitor.
If your monitor screen remains blank after using the previous procedure, check your video
controller and computer system; your monitor is functioning properly.


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Location: Far, Far Away


danielsoy
New User

Jun 26, 2014, 3:33 PM

Post #7 of 15 (1967 views)
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Re: [jts1957] Hello. [In reply to] Can't Post

Model is:

Front :Samsung Syncmaster 2233
Back cover sticker:LS22CMYKFNA/ZB11329

Service Manual:
http://www.4shared.com/...chassis_ls22myn.html

Monitor inner view:
https://www.youtube.com/watch?v=OzkXw6molww

clkout signal from main board connector, to lcd panel (20nsec hor timebase)
https://www.youtube.com/watch?v=yXStE0CfRyM


jts1957
Veteran


Jun 26, 2014, 5:42 PM

Post #8 of 15 (1962 views)
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Re: [danielsoy] Hello. [In reply to] Can't Post

Did you perform self test and check for the fuse?Unimpressed


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Location: Far, Far Away


danielsoy
New User

Jun 26, 2014, 8:33 PM

Post #9 of 15 (1959 views)
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Re: [jts1957] Hello. [In reply to] Can't Post

Yes, i did it ,but no luck....

BTW, there some meaningfull oscillograms on the LCD panel board,
so i know that it has vcc and I can see some signals that look like rectangular clocks.

But canīt tell for sure, who is the culprit.


jts1957
Veteran


Jun 26, 2014, 9:28 PM

Post #10 of 15 (1954 views)
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Re: [danielsoy] Hello. [In reply to] Can't Post

Did you check for a fuse on the TFT attached PCB?


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Location: Far, Far Away


danielsoy
New User

Jun 26, 2014, 10:38 PM

Post #11 of 15 (1952 views)
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Re: [jts1957] Hello. [In reply to] Can't Post

Yes, I found one fuse marked as: FU1, and it is not open.


jts1957
Veteran


Jun 26, 2014, 11:30 PM

Post #12 of 15 (1949 views)
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Re: [danielsoy] Hello. [In reply to] Can't Post

Then, unless you can find a schematic for the panel assembly and repair the board, I'm going to agree that panel is bad. Subbing is only way to prove.


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Location: Far, Far Away


danielsoy
New User

Jun 27, 2014, 2:13 AM

Post #13 of 15 (1945 views)
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Re: [jts1957] Hello. [In reply to] Can't Post

Thatīs right.
If I find info about the panel, will post back.

Thanks a lot for your help JTSTongue


jts1957
Veteran


Jun 27, 2014, 2:58 AM

Post #14 of 15 (1943 views)
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Re: [danielsoy] Hello. [In reply to] Can't Post

What is panel nomenclature?Cool


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Location: Far, Far Away


danielsoy
New User

Jun 27, 2014, 1:43 PM

Post #15 of 15 (1938 views)
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Re: [jts1957] Hello. [In reply to] Can't Post

Chunghwa 215FA01S.

Found this pdf.

http://www.4shared.com/...duG/lcd_dispaly.html

 
 
 


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