T20, T21 LCD questions

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clickpoint · #1 Post by **clickpoint** » Sun May 06, 2007 10:49 pm

I received 2 TP bases, T20/21 from a friend. Am waiting for Keyboard to see if they will work at all..... While I am waiting, how would I find what LCDs would be compatible w/ them?? If I use a nonIBM LCD, do I need to get a different inverter or use the one specific to the machine?

Thanks!

#2 Post by **rkawakami** » Sun May 06, 2007 11:15 pm

The LCD panels used by the factory are listed in the T2x Hardware Maintenance Manual. Note that you must match the video ribbon cable to the panel being used. Assuming that the pinout on the back of the LCD panel matches, I suppose you could use a non-IBM spec'ed panel. The type of CCFL (backlight) in the panel would probably dictate what type of inverter could be used, but seeing as how there is only one inverter used by all of the T2X systems, you're probably stuck with using that one.

clickpoint · #3 Post by **clickpoint** » Mon May 07, 2007 8:48 am

Thanks for the link......
Can I use either the 13 or 14" LCD with any T2X base, or is it specific to the model? Also, does it matter if I use XGA vs SXGA ?

Website · #4 Post by **tfflivemb2** » Mon May 07, 2007 12:37 pm

You can use a 13 or 14" LCD depending on whether or not you have the correct upper display bezel to go with it.

As for the XGA or SXGA, you can use either, but you will need to make sure that you have the corresponding LCD cable. The SXGA and XGA use a different LCD cable.

The part numbers for each of the above are available in the HMM referenced in Ray's link...

Stargate199 · #5 Post by **Stargate199** » Mon May 07, 2007 12:38 pm

The 13.3" LCD and 14.1" LCD have their own specific ribbon cables you must use. Make sure you have the correct one to use with size of the LCD you have. The T20 only has XGA as the resolution. Only T21s that came from the factory are able to use SXGA+ panels because they have a different video chip that supports that resolution.

clickpoint · #6 Post by **clickpoint** » Mon May 07, 2007 7:41 pm

THANKS!!!!!
Keyboard arrived, and gave it a try...
All I got was 3 beeps, 3beeps, 1 beep

Could it be the memory I have on board? I've ordered more, but am waiting

#7 Post by **rkawakami** » Mon May 07, 2007 9:15 pm

Beep sequence indicates a memory problem. There is NO on-board memory in the T20/T21 so if you have any module(s) in the two SODIMM sockets, then they are not PC100 or are defective.

clickpoint · #8 Post by **clickpoint** » Tue May 15, 2007 8:29 am

rkawakami wrote:Beep sequence indicates a memory problem. There is NO on-board memory in the T20/T21 so if you have any module(s) in the two SODIMM sockets, then they are not PC100 or are defective.

Got the memory ; solved the problem.

Found 3 lcds :
1> Horizontal lines across it (gray colored)--multiple : bad lcd?
2> Very dim , I think I see logo at boot : backlight vs inverter
3> Yellow tinge, but can boot and see bios : inverter?

Thanks for the help everyone!

#9 Post by **rkawakami** » Tue May 15, 2007 10:02 am

1) Probably a defective panel; could also be a ribbon cable problem.
2) Age-old question when there's no backlight; best to try swapping in a known good inverter. If that doesn't work, then the backlight is bad. Smaller chance that the ribbon cable is defective/loose.
3) Any color tinge (pink, red, yellow) usually indicates that the backlight is on its way out. Very small chance that the inverter is not putting out enough voltage/current.

clickpoint · #10 Post by **clickpoint** » Tue May 15, 2007 11:56 am

rkawakami wrote:1) Probably a defective panel; could also be a ribbon cable problem.
2) Age-old question when there's no backlight; best to try swapping in a known good inverter. If that doesn't work, then the backlight is bad. Smaller chance that the ribbon cable is defective/loose.
3) Any color tinge (pink, red, yellow) usually indicates that the backlight is on its way out. Very small chance that the inverter is not putting out enough voltage/current.

1 - tried different cable, still same problem
2 - will try inverter
3 - backlight fix sounds complicated

If it's the LCD / backlights that have gone -- is there a place to recycle the LCDs?

#11 Post by **rkawakami** » Tue May 15, 2007 12:11 pm

The backlight replacement can be hard to do; I have not yet tried one but am still planning on it. You could have someone do the backlight replacement for you. I think that basscleff has performed this service in the past. You also may be able to sell the panel here in the Marketplace as somebody may like that kind of project.

As the LCD panel contains a fluorescent lamp (the backlight), it has a small amount of mercury in it. So you have to treat the panel as such. I believe that most any place that accepts fluorescent lights for proper disposal will also take LCD panels. You may have to call around to some local recycling centers and see what they say. Just make sure that they know it is an LCD display and not a CRT.

clickpoint · #12 Post by **clickpoint** » Tue May 15, 2007 1:26 pm

rkawakami wrote:The backlight replacement can be hard to do; I have not yet tried one but am still planning on it. You could have someone do the backlight replacement for you. I think that basscleff has performed this service in the past. You also may be able to sell the panel here in the Marketplace as somebody may like that kind of project.

As the LCD panel contains a fluorescent lamp (the backlight), it has a small amount of mercury in it. So you have to treat the panel as such. I believe that most any place that accepts fluorescent lights for proper disposal will also take LCD panels. You may have to call around to some local recycling centers and see what they say. Just make sure that they know it is an LCD display and not a CRT.

Thanks... question, are backlights "specific" to the LCD.. since the one with the "gray horizontal lines" across is already "shot" ; could I use the backlight from it to put into the one that is "very dim"??

#13 Post by **rkawakami** » Tue May 15, 2007 1:44 pm

The backlights (CCFL) are only specific to the panel in that they are a certain length and that they will be powered by a certain inverter. If the panels are all the same size (i.e. 14") and are for the same system, then I'd say you have a very good chance of swapping backlights. However, they are normally available for around $10-$15 new. Better to replace the lamp with a new one, than with one with an unknown history.

I would use the "shot" panel to practice your disassembly/assembly procedures before attempting it on your "real" patient. That's basically what I have done by buying a T23 system with a broken SXGA+ panel. It's the same type that I will be trying to revive later on.

clickpoint · #14 Post by **clickpoint** » Tue May 15, 2007 1:47 pm

Is there a reputable seller that you would recomend?

#15 Post by **rkawakami** » Tue May 15, 2007 2:32 pm

If you haven't seen this thread yet:

http://forum.thinkpads.com/viewtopic.php?t=3705

it has some good information on what is needed when replacing the CCFL. I think it refers to Moniserv.com as a source of replacement backlights. I believe this is the seller that others here have used to replace their lamps.

T20, T21 LCD questions

T20, T21 LCD questions

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