Can't enlarge my lcd panel. Help

[junglemike]

Hello. I've bought broken A21m thinkpad.
I've fixed it and it's very nice laptop.
The big disadvantage that it has small 12" 800x600 lcd panel.
I've checked on the net - and there are A21M with 13,1 and 14,1 inch 1024x768 lcd's.
Just in case I have a spare 14,1 lcd.
I've connected this 14.1 lcd instead of 12.1"lcd and this is how it looks:

full image:

It only uses 800x600 pixels. Space to the right is unused (black) and space beneath just repeats itself.
How do I make it recognize full 1024x768 pixels?
There's no option to set any other resolution except 800x600 in display settings.

[schen]

It's looks to me like you just used the cable that was there when it had the 12" panel. I believe you'll have to use the correct cable for the 14" panel and it should solve your problem.

[AlphaKilo470]

Yeah, the cable is the part that makes the difference. I had a friend replace the 12" LCD panel on an A21m with a 15" XGA panel and it worked just fine.

[junglemike]

Thanks for reply.
How can this be possible?
Yes, I used the cable that was with 12" lcd, I just replaced the lcd panel.
The connector for 12" and 14" - is the same connector (obviously, otherwise I wouldn't be able to plug it in the lcd.

So Are you saying that the cable - is what makes the difference?
How's that??
There's isn't any electronics in the cable - it just wires that connector the motherboard to the lcd.
So How is laptop going to know to switch resolution to 1024, if I put another cable?

Please explain anybody.

[AlphaKilo470]

The wiring is different.

A similar setup is seen on the PowerBook Duos of the early 90s. I once replaced a broken TFT panel on a Duo 250 with a Duo 230 ST

Just because the carton says milk on it doesn't mean it can't hold something else.

[SaberX]

this might be silly but when you booted up with the new 14" did the laptop find the new display and set it up as a thinkpad 1024x768 tft panel?
I did the same switch in a A21 last year(i just switched the whole lcd lid tho).But the 14.1" was still set up for a 12.1 800x600 display.
What happens when you just change the display rez to 1024x768?