CF-29 LCD questions

Hello all,

Panasonic CF-29 Toughbook 1.3 MHZ 384 MB RAM

This computer is a work computer for a local PD and one of the users reported a flickering screen. I checked it out and the screen flickers a bit then goes dark. It now remains dark at all times although it boots fine and you can see everything in the background if you look hard. Same issue as several others and a new LCD inverter was the solution. I got a new CF-29 inverter and to my dismay, (and my bosses) it did not cure the problem. I hooked it up to a known good CRT monitor and the screen was brilliant through the welcome screen. The monitor then clicks and goes to stand by mode. My question is could it be the video card or the backlight bulb? I didnt think the video card since the CF-29 screen works...you just cant see it right. And why did the CRT go to standby mode? I have another good CF-28 LCD screen and will try to replce it if I am confident it is a screen (backlight) problem.

Thanks for reading and thanks for any responses as I could use direction to get this back on the road by Monday.

Kevin

 

My vote is the backlight is toast. I don't know why that would affect a CRT though, that stumps me.

 

The VGA output was probably using a scan rate the external monitor does not support.

Try pressing F8 repeatedly during the BIOS startup screens to get the Windows boot options menu, and select 'VGA Mode'

This should work with the external monitor & allow it to stay active so you can set a suitable video mode.

 

I'd say backlight too... And make sure that you are enabling external video in the BIOS.

Which brings up another good point... Can you go into the BIOS and the screen stay on? Try that with the LCD and external and see what happens.

 

Hi! Guys, I'm back after a couple of weeks of hardwork. BTW, I am with the three guys, Doobi, rj..and TB. Your backlight bulb need to be replace or if you don't have a capability to do that I suggest to change the whole LCD display and by your idea of chnging the display from CF-28, I think it will not gonna work( correct me if I am wrong) cf-28 uses diff...LCD. With regards to your other question, why the crt goes to stanby mode.Its probably not set to the right resolution and if you barely seen the whole image on the cf-29 screen it means that your video card is working properly. As they said your backlight bulb is toast but be careful enough on buying a backlight bulb it must the same same lllum..tion/brightness as if not it gives you lousy color like greenish or maybe bluewish.


ohlip

 

Thank you all for the quick advice.. I will probably make a attempt to change the backlight. I've never attempted it before but i've had LCD screens out and am somewhat inclined. I've checked other directions on replacing the backlight bulb but is there a thread here, or can anyone give me direction on how to change the bulb on a CF-29? Are the LCD screens pretty similar?
Thanks again for the helpful advice,

Kevin

 

I already changed one its not as hard it can be. If you have patience. Its like a reverse engineering. Good luck!


ohlip

 

Teo... Good tip.
I changed a backlight around 2 years ago and got a way green tint when I started it up... So Teo is right... Make sure you buy from a reputable place and they know what you need.

Teo, any idea of where to get the proper ones?

 

I bought a known good backlight not on the reseller of backlight bulb. I bought mostly an lcd with crack screen with known good original backlight. Its tough decission to make to do that coz you'll never know the lifetime of the bulb but so far so good. It cheaper than those bare backlight bulb they are offering, for only 5-9 buck. I ask question from seller about the detail of it before I bought it. Anyway, you can be sure its an original one. I will never buy again to those reseller again of backlight bulb after my first experienced to those guy.


ohlip

 

Bugly, I do have a broken LCD with a good backlight. Now i don't know how much lifetime the bulb has left but I let the screen go pretty cheap or maybe free. PM me and we'll talk about it

Dan

 

Thats what I'm talking about. A junk to others but gold to someone. Lol

Now! who has an upper bottom case of cf-29 mk1 or mk2 in decent condition as i need one.


ohlip

 

I got a case from a cf29 mk5 that i won't use cuz the motherboard had corrosion all over it. will that work?

Dan

 

If not Teo, I have an MK1 29, non-touch, top lid is in need of replacing but everything else is working perfect. I was going to sell it as a part machine, but if you need the bottom, let me know.

Paul

 

Paul,

You're parting it out but its gonna take your time and also I am not on a rush. I can wait till its available. BTW, I checked this morning my spare docking connector of Sled for cf-29 and its not worth it to mod as it has a corrosive pin leg and the other one that you sent to me before is only for gps sled as it has no antena connector for both u.fl and mmcx. Do you have any other spare so that I can finnish and send it to you? For cable ribbon its ok I still have two more with the connector at the midle for WWAN control.



Dan,

I think it will gonna work as I done it before by just making an exact hole at the back for ps2 jack instead of usb. I will pm you later. Thanks to both of you guys.


teo

 

I am pretty sure I do. I will check when I get home today.

 

Thanks for all the great replies...and a special thanks to Psych0Thrasher for hooking me up with a backlight. I was able to get into the bios and saw that the display was set at "simultaneous" which should have worked with the external monitor. I changed it to read "external monitor" with no difference. I also tried "internal LCD" with no difference. The external monitor is a 15" NEC LCD. It gets to the Wecome Screen then it goes to powersave with "no signal" display. Is there another adjustment to be made in the BIOS? I dont need to get a external display to work but want to be sure there isnt another problem other than the backlight.

Thanks again everyone and any suggestions will be appreciated

Kevin

 

Do u have a freezing spray and a hair dryer? So u can check, if there is a temperature problem on the graphicchip or on the inverter (but don't overheat it (no more than 70'Celsius). Maybee also an cold soldered connection. Do u know how to do it or should I give u a guide?

 

FOUND IT!! Sending you a PM...

 

OK I received the backlight yesturday from Psychthrasher (Thank you Dan) I unpacked it and plugged it in and no difference. I took the light out and left it in the reflector shield but saw no light at all. I am sure the light works but will check it tomorrow on another toughbook. So I tried a good backlight and a new inverter with no improvement. I still have the issue with the video...I connect a external monitor and it works fine until the welcome screen where it goes black, along with the no signal screen. The toughbook will continue to boot up but the screen is dim and can only be seen with a flashlight. Could the video card be suspect? Could I have extremely bad luck and have a bad inverter out of the box? I will see if a friend can check for power at the inverter next. I am out of ideas and really could use some more excellent insight.

Thanks for reading my long post,
Kevin

 

damn...this 404


It sounds strange to me. You've got a working backlight and an inverter and still nothing? As you mentioned its stil have an image on the screen but dim. Therefore I suspect that you have a blown fuse on the MBO. Either the F5 or F6 which are part of a protection for backlighting.


ohlip

 

Schematics..... Gooo!!!!
I only have the schematics for the 28. anyone got the one he needs?

 

Not so sure I have a good test light.. I tested it on a known working CF-28 and it didnt light up. I am going to test the current at the inverter and post the results. The inverter is new out of the box but I am suspect since, even though it is the same length as the other one, it isnt quite as wide. Not sure if it makes a difference. I provided the CF-29 model number to the guy at he radio place who ordered it soI assume it is correct..but?

Kevin