CF-20 Dead Screen?

Hello, recently I've come into possession of a Toughbook CF-20 via a police auction. I doesn't have the M2 SSD or either battery in it, but the more pressing issue is the lack of video. The built in LCD seems totally dead, as it doesn't even light up the backlight when the unit is powered on. I really don't know what could cause this, and the unit is otherwise in great condition.

I got it to output video via HDMI to a TV *once*, but I foolishly hit the screen switch button (Fn + F3), and I haven't gotten it to output through HDMI or VGA since. In that brief period I did confirm it powers on though, and the touch component of the screen worked when I clicked the "Click here to access BIOS" prompt. It brought the system into the BIOS settings, but this is where I hit the screen switch key, so I didn't get to look through the settings.

I've power cycled it more than a few times, left the hot swap and CMOS battery unplugged for a while, disconnected and reseated the monitor ribbon cable on both ends, tried it on and off of the keyboard, pressed the monitor switch key many times, tried both a different HDMI cable and a different TV, shined a flashlight onto the screen to try and see if it was just the backlight, but no matter what I do, the screen stays totally blank.

Does anyone know what would cause this, or maybe heard of this happening to other CF-20s? I doubt the lack of a battery or SSD would do it, but then again I've never owned one before, so I can't say for certain. It seems like whatever is happening is due to abrupt component failure, versus any obvious abuse. Any info or insight is greatly appreciated.

 

Hi
You dont need a battery or hard drive for the machine to turn on. if a monitor is plugged into the laptop it should normally come on for a bit to at least show the panasonic screen.
check to make sure the right voltage from the adapter.
I have similar model to the but Japanese let's note version, business laptop. The parts for this machine are expensive at the moment. Normally i swap motherboards, ram or screens to test. I think the ram is soldered on the board like my model. If i wanted to fix it I would look for a parts machine to replace components but these are still to expensive to swap. These are fairly tough machines but being a ex police laptop, who knows what abuse it went though or what kind of damage.

 

The adapter is supplying what the unit calls for, 15.6 volts. The unit is otherwise in good shape, no scratches or damage to the screen, or anywhere else. It seems to have been used in laptop mode for its entire service, either in a vehicle or in an office. I'll try and run what appears to be a part number on the panel, and keep an eye out for a replacement, but I'd just like to make sure that would actually fix the issue before making that sort of investment.

 

It seems to be a common problem with CF-20 video. I already saw many items with dead screens for sale.
But all my CF-20's work well.
It would be interesting to test with spare/compatible panel.

 

Have you tried pulling the memory out and putting it back in ?

 

Is the memory upgradeable on these models or soldered on the mobo?

 

It's non-upgradeable on this model. I thought of re-seating the RAM, but there simply isn't anything to re-seat.

 

that is what i thought. i have seen lots of screen issues with though with similar business models. they usually turn yellow and have other issues but it should still display out of the hdmi port or vga. not sure if it has both or you tested both though. You should see some sort of image at first power on

 

I already checked the HDMI and VGA multiple times, as outlined in the OP. I also tried both the HDMI port on the keyboard, as well as the "tablet" itself. Absolutely no signs of life on the built in screen, or the external monitor.

 

I work with Toughbooks as technician, and I have seen the problem very common lately. I am wonder if anyone could figure this issue. Is definitely a Mother Board issue, I swapped with another one and everything looked normal.

 

Have you tried shining a flash light on the screen to see if it’s a backlight issue?

Also it may be a blown fuse on the motherboard if it is a motherboard issue as noted above.

 

Yes, is not backlight (at least on those I have), This issue have happened under different scenarios, even when just connecting the keyboard, or after removing the M.2 storage I turn it on and no more video, things like that...I don't know what it is.

 

The 18/19 series I have run across several that just refuse to turn back on. I pull the battery, cycle power switch a few times, then pull the motherboard completely out and removing all batteries, even bios battery. Every single one has went back to working. Even had a few on the boards to do it and their machines have gone back to working.

wonder if this would work on this one.

 

do you have a model number for the screen and a pic of the connector. i want to see if its the same screen as the business models. I have a few of them and almost all first gen had issues with yellowing and worse