Toughbook CF-30 CCFL Backlight Failure

Hi all. Hope you are all well. A few days ago I noticed a flickering of the backlight on my CF-30 Mk3 which progressively got worse until today when the backlight failed. If I turn the laptop off and on it will run for a bit but then drops out completely again.

I'm presuming this is the inverter that is on the blink - given that it is a failure from both sides of the display. The CCFL tubes are quite yellowed and if the numbers are correct the laptop has run up around 30,000 hours - although it is in excellent cosmetic condition.

So the question is - LED conversion or replace the CCFL's and inverter? I'm presuming the inverter is a Toughbook specific part and a generic unit wouldn't fit (although I am also presuming that the CCFLs can be bought from a 3rd party supplier)?

I *can sometimes* be fairly handy when it comes to electronics but TBH the more difficult the job the more I'm likely to mess it up. Although I have been known to swap positive and negative on the simplest of circuits!

I'd like to do the LED conversion, but need some comforting words before I take a screwdriver to my lovely CF-30!

Thanks for the help - and all the previous trail blazing that makes this even a possibility.
I'm considering the following LED backlights: http://www.ebay.co.uk/itm/111748838166

 

this

http://forum.notebookreview.com/thr...-tube-into-an-led-backlight-cf-30-lcd.739952/

and these

http://forum.notebookreview.com/threads/led-lcd-conversion-cf30-500-nit-panel.756155/

http://forum.notebookreview.com/threads/changing-from-ccfl-to-led-display.471036/#post-6067167

 

The LCD and inverter are easy to replace,if you don't feel comfortable doing a LED retrofit.

 

Thanks for the help. I've reviewed the three posts about LED replacement again. I have contacted the seller of the LED strips to determine whether they are suitable. I'd like to convert to LED's, so if I can do it at a reasonable cost I'll give it a go.

Cheers, Mark.

 

I had a response from the seller - with a question. I wonder if anyone can confirm this?

So this panel uses two CCFLs.
First check if original inverter input has the same regulation as usual inverters
5v on start up and 0 till 3,3v regulation​

Thanks, Mark

 

Schematic lists it as Vc5, so I will say 5v.

 

while i like the idea of leds over ccfls the realities are another story .
having recently had a go at retrofitting a led strip into an exceedingly dim '52 (they were like that brand-new) , there are a couple of considerations ...
a major problem i ran into was the "stage footlight" effect ... this comes from the fact that the diffusion characteristics were designed for a lineal light source , not the "spot sources" that a led strip has .
this effect is a deal killer for me ... with some other issues on the side (such as the way that the pwm is done with cmos driver/buffer) .
if it were me , i would replace the ccfls and an electrolytic cap on the inverter board and call it a day .

one could always replace the whole lid assembly but unless the '30 has been sitting in a closet for many years , the ccfls in these machines are going to be "tired" .
i do not know if it is possible to retrofit a whole lid assembly from a '31 onto a '30 base , but if all things jibed , this would be the way to go .
the voltage supply for the inverter and the "direction" of the pwm signal are the first two major concerns (although , one could make an inverter for the pwm signal) .

 

Thanks for the info CWB32. Regardless of what I decide, is there an obvious fault that causes these symptoms? I'd be quite happy to replace an electrolytic or two on the inverter board to get the machine up and running again till I decide what I want to do as a permanent fix. If I went down replacing the CCFLs - are they a standard part I can get from a 3rd party supplier? Is it simply a case of getting tubes the correct length?

Cheers, Mark.

 

This is the listing I'm currently looking at for CCFLs: http://www.ebay.co.uk/itm/111734035133

 

They appear to be ok.
You may have to do some minor custom work with the rubber ends since the CF30 uses 2 tubes side by side.

 

Would I need to be ordering 4 tubes in total?

 

No just 2 tubes per lcd panel.

I would recommend picking up a used lcd panel and swap the panels.
This gets your CF 30 up and running and allows you take your time to swap out the tubes on your panel. Then you can swap in your rebuilt panel once it is done.

 

the electrolytic caps like to "fade away" simply because of age and is the nature of the beast .
the "beast" is filtering/decoupling (aka : provide a low impedance path) the garbage and hash from the switchmode supply ... this is hard on electrolytics .
there are various grades of electrolytics ...
currently (i'll take the pun) there are two major families : 85C and 105C .
the 105C types are designed for more abusive *environments* (physical and electrical)
the 85C types are used in more "relaxed" situations (think : inside a stereo , tape deck , etc .)
a switchmode supply will beat the snot out of a 85C electrolytic by virtue of hitting it with square waves (well , pretty much square waves) ... so much so that they will fail (catastrophically at times) in short order .
just ask anyone who has replaced a 105C cap with a "plain jane" ... when timed juuust right it is a good trick for new year eve at midnight .
(yours truly has had a fair sized one grenade about a foot from his face)
in power supplies , when used as a coupler or filter there is an appreciable amount of current required from them ... this requires robust internal construction as well as low inductance and low ESR (equivalent series resistance) .
back in my formative years (read *girl chasing*) ESR was known as "power factor" ... a little google-foo will expand these two items and hopefully allow more sense to be made from my ramblings .
while switchmode supplies are much more efficient than their linear/shunt regulator brethren ... they are a different breed of cat and require more appreciation of what a square wave is , the effect with inductance and a few other things that one does not normally consider in fine detail with 50/60Hz AC or DC circuitry .

just like other electronic components , there are *cheapo* and *good* types ... panasonic and nichicon are two good types .
taking the lcd apart is a bit time consuming and keeping things clean is of great importance ... you will see every speck of dust that you miss .

as shawn mentioned , there are two lamps used in the '30 lcd ... if you can thread a needle , this should present no real issues .
don't forget to keep track of those "spacer rings" ... they are almost invisible and will get stirred into the surroundings quickly .

 

Greetings from the Lake District, NW England!

Not been on here for ages but I can report that after over two years of sitting in bits I finally managed to muster the courage to replace the LCD panel backlight tubes on my CF-30 with ones that I had bought from a company in Poland.

It was an awful job and it didn't help that somehow I decided to do it with a hangover I did manage to put a scratch on the LCD itself (errant screw) and it took forever to convince myself that the bottom of the panel housing which is like a sprung clip was in the correct place (actually, I'm still not convinced, but it isn't coming out again!)

However... having said all that it did go back together and does work and I've been using it out in the field again which is great. Still have a lot of affection for it! I do amateur radio and it is great for digital modes such as FT8.
Bizarrely after two years the battery was still at full charge and apart from a slew of Windows 10 updates it works a charm with both Win10 and Ubuntu.

So just to say thank you for those who offered advice last time I asked.

Regards, Mark. M0NOM

 

thanks for the update and success story.

 

I just reopened the original thread and moved your new thread to it. Thanks for the update.