T22 display flickering

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dwilsonfl · #1 Post by **dwilsonfl** » Sun Oct 22, 2006 8:22 am

The display on my T22 is flickering intermittently. Not flashing, or going black, but flickering from normal to dimmer. I read what I could find in the archives and eliminated the switch.

I haven't checked it with an external monitor yet, I'll do that later today.

What else would I look at or replace?

#2 Post by **rkawakami** » Sun Oct 22, 2006 11:47 am

dwilsonfl wrote:What else would I look at or replace?

Going from lowest cost to highest....

Check all of the connections starting from where the ribbon cable plugs into the motherboard, all of the way out to where the inverter board is. Sometimes re-seating the connector in the motherboard or re-seating the inverter board inside the lid can cure that problem.

If re-seating, wiggling, etc. doesn't eliminate the flickering, replace the inverter board. $10-$20 on eBay (FRU 10L1402).

If the replacement inverter does not get rid of the flicker, then what's left is the backlight, or realistically, the entire panel. You could attempt to R&R the CCFL backlight from the LCD panel, but I would not suggest it unless you have done something like that in the past.

dwilsonfl · #3 Post by **dwilsonfl** » Mon Oct 23, 2006 9:04 am

If I turn the backlight down, it doesn't flicker. Of course I am going blind this way...

In the corner of the LCD, the bottom right and left - over the "start" button and the clock, the screen is darkened almost like a florescent bulb would be. The portions that are darkened (you can still see through) are fingerprint sized.

The LCD has some pressure points of light areas as well.

If I buy another whole display off Ebay, it will be used too and I'm not sure if I wouldn't be right back in the same place sooner or later.

#4 Post by **rkawakami** » Mon Oct 23, 2006 1:01 pm

dwilsonfl wrote:If I turn the backlight down, it doesn't flicker. Of course I am going blind this way...

In my mind that could still be a weak inverter or an about-to-fail backlight.

dwilsonfl wrote:In the corner of the LCD, the bottom right and left - over the "start" button and the clock, the screen is darkened almost like a florescent bulb would be. The portions that are darkened (you can still see through) are fingerprint sized.

An LCD backlight IS a fluorescent lamp. That does indeed describe a "burn" mark at both ends of the tube.

dwilsonfl wrote:The LCD has some pressure points of light areas as well.

Only solution I know for that is a replacement LCD.

dwilsonfl wrote:If I buy another whole display off Ebay, it will be used too and I'm not sure if I wouldn't be right back in the same place sooner or later.

Not necessarily (old or used, that is). You could probably find a brand new panel ($$$$$) that would fit inside your system. Of course the used ones are a little cheaper. Like any used piece of equipment being offered by an eBay seller, you have to rely on their feedback and stated warranty/guarantee. As to the life expectancy of LCDs, they should last at least 4-5 years in normal operation. If you want to know how old a particular panel is, there should be a date code or marking somewhere on the back side. You could ask the eBay seller for that date. And one thing I just remembered from reading about fluorescent lamps awhile back... This was about the compact fluorescent lamps now being used in the home, but I think it applies to any fluorescent tube. It was said that the lifetime is reduced by frequent on-off cycles. It is better to keep the light on if you will be using it for a period of time. Put into computer/laptop terms; don't set the Windows time-out delay to one minute if you're going to be using the system for a while.

dwilsonfl · #5 Post by **dwilsonfl** » Mon Oct 23, 2006 8:27 pm

replacement on the way off the bay. Just couldn't pull the trigger on a new laptop.

#6 Post by **rkawakami** » Mon Oct 23, 2006 9:12 pm

I just noticed in the other thread that popped up about the same time, concerning the same issue (T22 display problems), where you posted that your backlight totally failed.

The lack of a backlight may still be due to a faulty inverter. If you replace the panel you will eliminate the black corners and pressure spots, but if you still use the same inverter, it may not light. I'm assuming you've ordered just the panel and not the total lid assembly (LCD panel, ribbon cable, inverter, hinges). If so, keep this in mind. And to double-check that nothing else has gone wrong with your video, the LCD panel still should show a "ghostly" image even without the backlight. Shining a bright light on the panel at an angle sometimes helps to see the pixels.

dwilsonfl · #7 Post by **dwilsonfl** » Sat Oct 28, 2006 4:34 pm

Installed the new complete assembly and it works great. No real problems doing it except for some issues with the CMOS battery connector. Almost went ahead and swapped chips but decided the 1 gigahertz for a 900 wasn't enough to mess with.

Thanks for the help.

#8 Post by **rkawakami** » Sat Oct 28, 2006 4:43 pm

dwilsonfl wrote:Installed the new complete assembly and it works great. No real problems doing it except for some issues with the CMOS battery connector.

Tough little bugger to get plugged back in, eh

? Glad to hear the replacement panel worked out for you.

T22 display flickering

T22 display flickering

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