Hi,
Need comments on the following point:

I found on some laptops, with internal display fail :TXLOUT0+, TXLOUT1+, TXLOUT2+ = 0.6V to 0.9V (on LCD panel connector ).

May I consider them as normal voltages and conclude then that video LVDS signals are present on connector?

Thank you for your help.

Those pins transmitting a digital signal, but ton linear. Use oscilloscope to view them.

Hi!
Do you know what kind of signal to be found at TXLOUT0+ with oscilloscope ?

some rectangle impulse. big frequency digital "0" and "1".

hi, sorry for this late reply.
vitaliy_mad, I would appreciate getting any illustration of the signals to be checked with oscillos on lcd panel connector.

Thank you

open any (almost) lcd screen pdf and view

by google something like that "LVDS signal photo"

resistance of lvds pairs must be identical

hi! you mean that resistance of a pair of lvds (positive and negative signal) must be identical, but I guess each pair might have different resistance from an other pair

Thank you for replying.

resistance between ground and each LVDS line must be same (identical)

vitaliy_mad answered the question

>but I guess each pair might have different resistance from an other pair

you can take a few "good" motherboard and check it )

You are wrong. It has long been checked. Resistance on all lines should be the same. The error is allowed in a few ohms.

Так а я о чем пишу - "resistance of lvds pairs must be identical" - all lines
и предлагаю человеку проверить самому свои заблуждения на платах
вообще подобные вопросы задавать странно, есть сомнения ну возьми кучку плат и все станет понятно

ну да сори. чет не дочитал. на этом форума много странных вопросов задают...

We are here in the forum to learn from each other, and there is no limit to knowledge, so p.s never consider a question as strange (странно)!

We are here in this forum to share our experience as knowledge has no limit, so p.s never consider a question as strange (странных)!

I agree with you, and that's why I answered to your question. I hope it helped you.

Anyway, thank you "vitaliy_mad". I already checked resistance on lvds signal pins on a working mobo, and find them almost identical, as you said.