Toughbookuser

Estimable
May 18, 2014
2
0
4,510
I have a Panasonic Toughbook CF-28. The LCD display is dim and best seen w/flashlight. The screen works fine on another laptop. I've put another working LCD screen on this laptop and get the same poor result. An external monitor works perfectly. There is no reason to change anything on the screens as I know they work. The display is poor in the BIOS. I believe it's a motherboard issue, I don't know if there is a fix.
 

plaintuts

Estimable
May 5, 2014
163
0
4,660
sorry for not noticing earlier.

just to clarify with the question...
the lcd display of the toughbook is dim, but if you use a external display plugged to the vga port of the toughbook, the external display is working fine.

if so, then..

the lcd of the toughbook has a broken CCFL bulb, essentially the lcd backlight that illuminates the panel.
 

plaintuts

Estimable
May 5, 2014
163
0
4,660
please reply on this thread...

oh, you tested other lcd's

ok if you really want to try for a fix, then the first suspect is ic chip in the mainboard..
also the connectors that bends on the hinges of the laptop.

but im sure its the CCFL on the lcd, because the screen is working but the backlight do not.

so check the connection running through the bezel of the screen for any abnormalities up to the connection to the mainboard.
if no issues found, then the solder on the ic chip may have chipped away.
 


Hi, when you changed the screen, have you changed the inverter also?
 

Toughbookuser

Estimable
May 18, 2014
2
0
4,510
I changed the inverter & got the same result-faint display. I put the LCD w/this different inverter on another Toughbook & got a decent display. If 3 LCDs don't work on it, but work on other laptops, I doubt it is the inverter or CCFL because they wouldn't display on another Toughbook. I've secured all the connections. Once again if it's a cable problem the LCDs wouldn't work on other Toughbooks. I'm sure it's an MB problem. I have no way of checking the integrated circuit on the motherboard. As I've stated previously, the external display is perfect & I've verified that I have simultaneous display checked in the BIOS.