Samsung SyncMaster 743N

[Hombre]

Hi

I have problem with this one.
When signal is applied the whole screen is red(ish). Without signal applied everything is ok ("Check signal cable" is normal as it should be).
Replaced all caps altough unnecessary because they were fine.
Tried it on two different PCs, with different OS just in case it is some driver problem, but no joy.
I assume it is digital board problem (it has only VGA connector, no DVI).

Any ideas?

[selldoor]

Re: Samsung SyncMaster 743N

Tried a second vga cable - check for broken bent pins in vga socket.

[Hombre]

Re: Samsung SyncMaster 743N

Ok, tried cable on another monitor, cable is good.
Resoldered VGA connector from another monitor, still the same red picture with signal on

[selldoor]

Re: Samsung SyncMaster 743N

Tried adjusting the colour - it mentions you can do this in the manual?

[Hombre]

Re: Samsung SyncMaster 743N

Yes, tried that too. If i set red to 0, green to 95 and blue around 35 then colour is about right as it should look. But if I reset it then to factory defaults it's red again, like default setting is Red on 100 .
OSD is normal, as you can see it on the picture.

[selldoor]

Re: Samsung SyncMaster 743N

Ok how about cleaning and reseating the lvds cable main to panel - again check pins

[lti]

Re: Samsung SyncMaster 743N

Some of these monitors have a color adjustment feature. The procedure will be in the service manual, but the manuals are so poorly written that I can't understand what they're trying to say.

This is what the SyncMaster 720N/731N manual says:

To Analog video, In 16gray or any pattern using black and white and any mode.(16gray and XGA mode recommend)
1. Push the OSD Menu button to open the OSD
2. Selectl language English
3. Push enter button during 5 seconds.
4. See the screen flashing

The process will probably be different for the 743N if it even has something like that. I have no idea what "16gray" is.

[stj]

Re: Samsung SyncMaster 743N

foto of the main board near the vga connector would help.
it may be a bad part buffering the input.

[Hombre]

Re: Samsung SyncMaster 743N

Ok guys, thanks for all your help, and especially to lti

Cleaned and reseated lvds cable, but that didn't help.
Then tried this metod that lti suggested and it worked! Get in OSD menu, selected english, hold enter button for 5 seconds, screen flashed and that was it

Thanks again!

PS: on picture it looks like it is still bit red display, but colours are normal

[lti]

Re: Samsung SyncMaster 743N

I didn't think that would work since those instructions were for a different monitor. That was just an example. The 720N and 731N are completely different.

A fault in the input circuit could cause this as well. I was looking at that in a SyncMaster 731N with a slight blue tint, but the schematic is missing the input section. The page marked "Input" is just a duplicate of the page with the voltage regulators on it. I just turned blue down to 31 in the menu.