CF-29 Screen problem

Hello all, I'm a newbie to the forum looking for some advice, I have just purchased CF-29ETPGBKM from a local university's surplus store hopefully to use for navigation on a sailboat, it will replace my GoBook Max. The unit was sold as having a bad LCD backlight and other than having the HDD removed it is complete. The screen shows no life at all, no dim outline of the BIOS screen, with or without a flashlight shining on it, however an external monitor does work.

Where should I start trying to fix this? I have searched the forum but didn't find any posts where the LCD was totally dead. Is it likely to be the backlight, inverter, loose connector? I would probably be more comfortable replacing the whole lid if needed rather than trying to seperate the various layers of the screen, does anyone have the complete lid with screen for sale?

 

they can run from 75.00-125.00 on fleabay the complete lcd assembly. I've purchased some from laptopaid and got lucky a couple of times and got an occasional assembly for 25.00. You have to rack up at least 15 posts to go to the buy and sell forum here. changing out the assembly is not terribly difficult and is certainly easier than changing out the screen itself but your issue might be an inverter which would be the least expensive thing to do. changing an entire working screen lcd assembly might be your best bet time and money wise. hope this helps..........Driller

 

If you can't see it with a flashlight then I think it's you screen but I could be wrong. Cheap price on a inverter $9.48 shipped
Panasonic Toughbook CF-29 Inverter Board 2138-B001-P1-0 - eBay (item 280595057742 end time Feb-24-11 12:41:44 PST)

 

Thank you Driller, Laptopaid does have one screen for 25, just the screen not the complete assembly, seems that some bare bones C-29's are going on Ebay for less than just the lids, two just sold in the last 24hrs for under $50.

 

Thanks toughasnails for the source for an inverter, I think I read somewhere in this forum that with a bad inverter it was still possible to see something in the screen, mine's totally dark.

 

First thing you have to do before or headed for a shopping. Give a glance on the harness cable that goes into the mbo. It maybe not be plug in into the mbo. connector. This is just to make sure its totally the lcd assembly problem.


ohlip

 

ohlip speaks wisely, I've swapped a lot of screen assemblies and on some the plug that mates to the MB( 2 of them?)the thinner on more to the right, has been cracked but worked when fully seated. got lucky there, you can't manhandle the wiring harness out and back in to re connect it to the MB, ask me how I know...Driller

 

Sometimes the simplest solution will work. You have tried toggling FN+F3, right? We have had members with this problem before and it turned out that the problem was solved with the hot key. Not implying anything, just askin'.
CAP

 

Setting in bios for internal/external or both monitors?

 

Panasonic Toughbook CF-29 LCD TOUCH Screen - eBay (item 130482749581 end time Feb-13-11 15:14:37 PST)
Panasonic Toughbook CF-29 LCD TOUC Screen - eBay (item 130482750195 end time Feb-13-11 15:17:59 PST)
Here's a possibility. They claim they are working.
Second possibility is the $50 units that you mentioned. Especially if you need parts.

 

CatSailor: as noted here, go into the BIOS (press F2 at the blue Panasonic bootup screen) and set the display to "Simultaneous" before going to the trouble and expense of changing out the display.

 

ohlip and Driller, thank you for the information I'll look at the connectors when i have to open it up.

Capt. Dogfish, thank you for askin', I am new to these machines and don't know any of the hot keys, I had not tried Fn+F3 I just tried it, it turns the external monitor on and off but has no effect on the laptops own screen. Would've been nice though.

deere245 and TopCop1988, I can get the bios setup screens on an external monitor and display is shown as simultaneous.

Gork, thanks, they are on my watch list, if I can pick up a bare bones unit for a similar amount I may as well have a few more spare parts around, ( or as my wife says more junk).

 

The FN+F3 has 3 positions, internal, external, and both. Give each click a little time, the response is not always instant.
CAP

 

CAP, just tried it again waiting between keystroke inputs as you suggested. I see what you mean, starting with the external monitor blank: Fn+F3 turns the extenal screen on, Fn+F3 again and it stays on, FN+F3 again turns it off. The laptop display unfortunately remains blank.

 

Progress, sort of. I checked the connections as suggested earlier in this thread and they looked good. Put the battery back in and powered on to check if pushing on the connectors had fixed it, I can see a very, very dim Panasonic splash screen on powering on, I took off the very thick screen protector and with a very bright flashlight I can just make out some text on the screen.

So I was wrong the screen is not totally blank, does this indicate a bad inverter?

 

Plug and un-plug several times. I "fixed" one by that method. Corrosion in the connectors.

HIGHJACK​

On the one I got today I have black screen but when I turn it on the green left hand light flashes once quickly and then all I have is the solid green on the right and another near the switch. And no sound. (beeps) Ain't this fun?
EDIT No hard drive light but I can hear the drive turning.

 

Yes , It's either the inverter or it could be the back light if you can read the screen with a flashlight

I have replaced inverter's before

 

Thank you all for your suggestions so far, but still no luck. I bought an inverter from Laptopaid less than $6 with free shipping! Didn't do the trick, so then I got a screen from the same place again no change, the backlight doesn't come on.
If I leave the lid split open and shine a flashlight onto the white plastic of the LCD I can easily see it posting. What's next? Fuse on the motherboard? Is the fuse on the top under the keyboard? Thanks again.

 

Previous posts about the backlight fuse.

fuse

fuses

 

Thank you deere245, I had read those posts, I am having problems physically locating the fuses. I have removed the cover plate under the keyboard and see where at the top (hinge side) of the motherboard it is marked [A]F6 N 2A, F4 N 2A and F5 N 2A. From the F5 N 2A there is an arrow pointing to a rectangular thing that has 'N' marked on it, is this the fuse? (I had read that fuses were marked 'F'). If this is a fuse then I see (barely) two more marked 'N' one each located adjacent to the connectors for the wires to the screen, am I on the right track? I have looked at the schematic but I'm more at home working on cars than computers. Does anyone have a picture they could post similar to the one ohlip posted in response to "CF-18 Dim screen. Need Help ASAP!!"

 

I've found the problem, if I hold a pair of fine tweezers across one of those components with 'N' printed on it the screen lights up. How on earth do you solder anything onto such a miniature fuse? I went to Radio Shack as it's local but their stuff is too big.

 

Don't do that again. It may coz another problem to other component and to yourself. All fuses on that area are mark N. If you can find a replacement fuse, look for other dead mbo. that has a zero resistor. It is almost the same size as of those fuses. Or you may just solder a very fine wire as an alternative or a defogger repair kit a very fine line will do the trick.



ohlip