LG LP154WU1-TLC1 mod incompatabilities.

[TPFanatic]

There is an incompatibility between the Radeon 3650 and the LG LP154WU1-TLC1 in Windows 7. The TLC1 was used in Dell Alienware Area 51 MX15 laptops and has the highest specs for a matte 15.4" display pin compatible with the Thinkpad. The TLC1 is unique in that it only supports 60hz.

The problem: when set to "High Performance" (ATI Graphics) mode, lowering the resolution will result in a black screen that renders the computer inoperable if it does not reset. I believe the issue persists in Windows 10 as well.

Solutions:
1. Replace the LCD.
2. Find a better driver, which I believe is impossible.

Possible solution:
3. Reprogram the TLC1's EDID to support 50hz.

Conclusion on the LP154WU1-TLC1: It is an amazing screen that stock works fully with T500's Intel chipset. It is unknown how it works in an Nvidia T61, ATI T60, or ATI Z60m.

I will swap one of my two TLC1s into my father's Intel only T500 so it will still be used, and steal his TLB1. And I will swap the other TLC1 into my ATI Z60m to see how the Sonoma chipset deals with it, and steal the TLA2 out of that Z60m. The TLA2, if I recall correctly, did not have these problems and I can survive the gloss.




...

I've noticed a problem when set to High Performance (ATI Graphics) mode in my T500, lowering the screen resolution to less than native in either Catalyst Control Center or Windows Display Settings results in a black screen on the internal display until it automatically resets. However starting up a full screen program that lowers the resolution renders it inoperable because it won't automatically reset. Audio and UI inputs are still registered, so with a hotkey I programmed I can "log off" the user and kill the offending game that way.

This does not occur when set to Energy Saving (Intel Graphics) or with an external display.

Notes:
My internal display is an aftermarket LG LP154WU1TLC1.
I didn't have this issue until a few months ago when I was playing with the graphics drivers. No amount of reinstalling drivers of various versions has since fixed it.

Hoping someone might know how to fix this issue... in the meantime I'll be documenting my efforts.



***

I suspect but am not certain of the following: The LP154WU1TLC1 only supports 60hz, Catalyst may be trying to force an unsupported frequency in lowered resolutions. This may not be relevant because lowered resolutions while certainly set to 60hz do not work.

It is important to isolate variables such as is the issue hardware or software? I can slide my drive into another T500 to determine if this is a software or hardware issue. If the issue does not replicate there is something wrong with my main's hardware, the LCD or possibly ATI death. If it replicates that means my Windows environment contains the problem.

I did built another T500 with a TLC1 that does not replicate these problems so I do not suspect the LCD is the problem. And problems caused within the OS can create incompatibilities with the LCD. So switching to a supported LCD could "solve" the issue, theoretically.

On to testing in another machine...



***

I slid my drive into another Switchable Graphics T500 with SHARP LQ154M1LW02 and the issue did not replicate, thus pointing to a hardware problem in my main T500.

To determine now is whether the issue is caused by my LCD or Radeon graphics chip.



***

The aforementioned second T500 with a TLC1, I tested it by switching to 800x600 in Windows set to High Performance with its own environment and the issue replicated now across 2 different computers, which suggests there is an incompatibility between ATI graphics and the LP154WU1-TLC1 at least in Windows 7.

So the mystery is solved.

Solutions:
1. Replace the LCD.
2. Find a better driver.

Since 2 is unfeasible I will look into what other 15.4" laptops I can put these glorious LP154WU1-TLC1 into. They are amazing screens and work fully with the Intel chipset.

[TPFanatic]

My LP154WU1-TLC2 (used in HP business laptops) has arrived and is installed in my T500. It has fully working brightness stepping and resolution scaling with either Intel and ATI chipsets. Contrarily the TLC1 could not resolution scale with the ATI chipset (but worked perfectly with the Intel graphics). 60hz is the only reported refresh rate for both TLC1 and TLC2.

LCD is plug and play despite having a funnier looking LCD-side connector.