[ltp] Replacing the backlight of the thinkpad LCD

[Richard Neill]

cupaxe wrote:
> Hello fellow LTP members,
> 
> My screen recently went blank on my thinkpad UXGA 15" after providing
> me with 4 years of honest service. Since I have run out of the IBM
> service warranty, I have the options, in increasing order of
> preference:
> 
> a) buying a new laptop.
> b) buying a new monitor screen, available from
> http://www.thinkpadmedic.com/, cost: $300.
> c) replacing the backlight opening up the monitor screen, available
> from http://www.ccflsurplus.com/lareba.html, cost: not sure.
> 
> The reason I think it is the backlight that has gone bad is because it
> works fine immediately after I start the laptop and 5-10 min after
> that, goes blank. It doesn't go completely blank though- I still can
> faintly see the underlying windows on the screen.

Indeed, the LCD is still working fine. No need for a costly new screen :-)
> 
> I have never attempted option c before but have experience replacing
> the fan, putting thermal grease on cpu, etc.
> 
> I would be delighted if you could share your experiences and other
> tips you might have for me.

Do go for (c). It should cost you in the region of $30 (maybe cheaper on 
eBay). You can't make anything worse. Note that it could be either the 
backlight or the inverter (or both).

In general, thinkpad maintenance is pretty easy - the documentation is 
excellent - see thinkwiki.org for more, especially for the IBM "Hardware 
Maintenance Manuals" as PDFs. Change the inverter first - it's easier, 
and more likely to be faulty (though neither is particularly hard).

3 bits of advice:

   - use a grounding cord to avoid static buildup. (frequently touching
     an earthed item will do, if you must).

   - there are lots of screws - keep them carefully separated and labelled.

   - use exactly the right screwdriver (buy a set of jeweller's 
screwdrivers if you need to). Also, carefully prise off the 
self-adhesive screw covers (5mm diameter, matte black things) with a 
very small flat-bladed screwdriver, and you can re-use them.


Richard


P.S. Backlights run at about 1000 volts. Don't touch the outputs of the 
inverter, unless you are sure that nobody will mind hearing you yelp bad 
words when you do!  Also, the CCFLs contain small amounts of mercury - 
try not to break the tube.