CF-W4 disassembly

Greetings!

The LCD display on beloved CF-W4 is going suddenly dark. I'm thinking it's either a loose wire, a dying inverter or a dying LCD.

I want to open it up and see if I can fix the problem. I'm not bad with the tools but I have no experience fixing laptops and can't find any directions on the internet.

Would you knowledgeable folks suggest just getting the screwdrivers warmed up and going to work? Or could someone point me to a disassembly guide hidden somewhere? Or is there another option?

Thanks in advance.
chip

 

I just emailed you a Service Manual. If you post your exact model number I can probably get a little closer... Unless this works for you...

 

Thanks, Toughbook. That manual is great, but if you have more information, I'd naturally be grateful. My exact model number is: CF-W4HWFEZBM.
chip

 

The one I emailed looks to be close enough... But if you need other part numbers I have others that include them I think.

 

I have the same problem: The LCD display on beloved CF-W4 is going suddenly dark. Any advice?

 

If it was fine ,and then you lost all screen brightness, it is most likely the inverter
If it over time has dimmed , thats a sign of ccf bulb burning out

 

Thanks for a quick response, Tomcat57!

Most probably it's a loose contact near the bulb. I found the disassembly manual (I can send it to you if you are interested; I failed to upload it as attachment due to the ridiculous file size limit for attachments) but I failed to quite understand how to disassembly the display pane. Here are more details:

For a year or so it was fine; then the following problem showed up:

When I turn it on, it's fine. In half a minute, the backlight suddenly goes off. If I turn off the screen power and then turn it on, the light returns for some seconds and then goes off again (suddenly, not gradually).

(To turn the power off I can close the lid and open it again; the Wizmo program can do it programmatically, so I call "wizmo monoff" and then hit a key to turn it on again.)

This continues for some 5-10 minutes: I turn the power off and on, and the light returns for some seconds. As the screen warms up, the light returns for longer periods and finally I can use the laptop normally. As months pass, this warm-up period gets longer -- at first it was a minute, then a couple of mins, now some 5-10 mins.

Even when the backlight is stable, if I touch or move the lid or shake the laptop, then the backlight suddenly goes off. To get it on again I need to again switch the screen power off and on; then the backlight is stable again.

Any advice? Or, do you know how to open the screen pane (I didn't understand it from the manual: section 2.2.20, last figure).

 

Agree, sounds like a connection problem...somewhere


Take note of
Hook Position

The panel is mostly held in place by hooks
Take your time when you separarate the panel , and try not to break too many

 

Greetings and thank you for this resource. I have to replace the screen on a Toughbook CF-W4. I can't find a take apart guide anywhere on the net. Any ideas on where to find one? Thanks in advance.

 

Toughbook, do you think it's possible you could e-mail me that assembly manual as well? I have a unit, a CF-W4, serial # CF-W4HWEZZBM with a broken screen and I need to replace it asap. Before I send to get a screen I would like to take this one off and make sure I order the correct replacement part. Thanks in advance for your help.

Cliff

 

What you're describing sounds like what we call a "gassy tube"; the CCFL is contaminated with air caused by a leak at one of the end seals on the CCFL tube.

There is no "connection" to get loose on these; the HV leads are soldered to the CCFL tube and there is never any mechanical stress on them to cause breakage. The PCB end of the CCFL connects via a plug-in connector, but that is pretty easy to inspect.

Any type of "loose connection" in the HV section of the inverter will cause arcing/burning which kills the inverter in short order; so this is NOT something you want to continue without investigating it promptly.

Odds are you have ONE CCFL tube which has failed this way; it is dreadfully hard to disassemble multi-tube LCDs without contaminating the insides of the panel with dust.

The other possibility is that you have either a failed Capacitor or a LOW-VOLTAGE power connection issue with the inverter; this could be either a solder joint with "ring cracks" or an actual broken wire.

My first suggestion is to disassemble the LCD panel and inspect the inverter(s) carefully; the fact that it's still working at all suggests to me that is where your problem probably lies.

Inspect the LCD panel with the backlight lit; if you see one or more of the CFL tubes which appear pinkish at the ends, there is your likeliest culprit.

mnem
Arc-welding with your inverters is NOR recommended...

 

What comes to mind is how some power devices will 'heal' after power is removed, but only for a few moments. If the back light seems to be bright then goes completely dark, I'd be more inclined to suspect the inverter myself. But, that's me.

 

You're assuming there is only one CCFL in your unit, I don't believe that is the case. You are also not considering a lot of other things which I, a professional repair technician with literally decades of experience, know about LCD panel repair but don't have time to explain here.

OP - please do yourself a favor; open up the LCD, inspect it as I've suggested. Don't continue to use it this way; you'll wind up having to replace an LCD AND INVERTER instead of just one or the other.

mnem
Zzzzt.

 

I'll not argue, I'll just drop it...

 

can you please email me the CF-w4 manual, i might be able to use it to disassemble my cf-w8 lcd

 

Here are 2 CF-W4 manuals:

http://tim.id.au/laptops/panasonic/CF-W4HWEZZBM.pdf

http://tim.id.au/laptops/panasonic/CF-W4GWCZZBM.pdf