R60 LED mod - inverter board - DIM?

[natumbri]

Hi,

I'm trying to install a LED strip backlight in my R60 15" 4:3.
The inverter is a FRU 41W1126.
I have a Unboosty-Blue driver board, which I will modify to take a pwm dimmer input.
I have instructions for getting VIN, GND and ENA off the inverter board, but I don't have a location for DIM (the pwm signal that I'll feed the driver board).

Can anyone assist?

Cheers,
Nik

[natumbri]

So the lamp driver IC on the 41w1126 seems to be the same lamp driver that IBM/Lenovo use on other inverter boards:
MP1010BEF

In PWM mode, it is recommended that the PWM signal should be connected to the DBRT pin (pin 4) directly. So that's where I'll look.

This amazing bit of pioneering work has some clues:
viewtopic.php?p=600367#p600367

[RealBlackStuff]

Those inverters are made by Hitachi, I think this is what you are looking for: https://i.imgur.com/iVQi9dC.jpg

[natumbri]

Thanks RBS - I actually went ahead and did it before you posted, using the PWM pin info from the datasheet.

I didn't have too much trouble with the inverter board, or modifying the led driver for PWM.

What I did have trouble with was getting the CCFL out of the LCD. I completely stuffed up the first one I tried. But I learnt what the inside of a LP150X08 LCD looks like. The second one went better and I managed to get the lamp out and the LEDs in without breaking anything.

Wired it all up and closed it all up. The led driver fits where the coil for the cclf used to be.

Results are pretty good, except there's a slight dimmer patch in the bottom LHS of the screen - possibly I didn't push the LEDs far enough to the left? Not incredibly annoying, except that it's not perfect.



LED v Unmodified.

Now, that was a low risk project - crappy xga display, that I had a spare for anyway (luckily). Question is: should I do this again on my (dim, yellow-green) T60 SXGA+ screen?

I have the bits, do I have the courage...

(I will not be putting a LED backlight into my SXGA+ R601 - it looks great just as it is, now that the EDID thing is sorted out.)

[RealBlackStuff]

I posted this years ago: viewtopic.php?f=31&t=88991

BTW: your pictures are not accessible, that Google Drive says:
Access denied.
You need access.
Ask for access, or switch to an account with access.
(I don't have a Google Drive, nor do I want/need it...)

[atagunov]

@natumbri: just checking - you have removed the transformer, haven't you?
As RBS said it's not possible to view your images, I also get "Access denied". Would you like to upload to imgur.com instead?
Also perhaps the most interesting question of all - what kind of LED strips are you using?

[natumbri]

Yes, thanks RBS - I read that very informative post about replacing a CCFL; I just managed to stuff it up the first time around, despite the assistance available. Oh well, live and learn.

The Google drive errors should be fixed now - I forgot to turn sharing on. Let me know if it is still broken.

As for LEDs, I bought a pair of strips and drivers for ~AUD$20 from AliExpress: https://a.aliexpress.com/_msdvGWR.

The driver boards turned out to be Unboosty-Blue. I applied the PWM mode mod, although I didn't bother with the current sense resistor. Probably should have, although maybe less important for a 15" screen (more LEDs and resistors in the strip than for the 12.1" @xiphmont was working with)? Also, didn't have a low profile inductor - it fits OK with the standard inductor, but would be better with low profile.

I did remove the transformer, and the CCFL plug from the inverter board. That left enough space for the led driver board (which has a plug on it).

[atagunov]

He he great work, congrats on replacing the backlight! After investing this much effort I wouldn't hesitate to use the machine even if bottom-left corner was a bit too dark.

It seems you chose not to remove the IC and diode bridge that Monty suggested for removal from R60 stock inverter?
How are the colors after the mod?
Does the resulting max/min brightness make sense?

Looking closer it seems AliExpress item photos show Unboosty, but they actually sent you an Unboosty blue?
That's probably good since blue is a bit better to work with isn't it..

We should really get permission from Monty and Bill Morrow and get a copy of Monty's website hosted on thinkpads.com.. Possibly with some new instructions and that photo from RBS

[natumbri]

Now, that was a low risk project - crappy xga display, that I had a spare for anyway (luckily). Question is: should I do this again on my (dim, yellow-green) T60 SXGA+ screen?

I have the bits, do I have the courage...

(I will not be putting a LED backlight into my SXGA+ R601 - it looks great just as it is, now that the EDID thing is sorted out.)

Answer is ... yes.


R601 standard N150P3-L01 v T60 standard LP150E05-A2


The same T60 LP150E05-A2, with LEDs. Still a bit green/yellow, and you can see the LEDs along the bottom 2mm of the screen, but quite an improvement for brightness.

Project completed - thanks COVID lockdown.

Issues that arose during the project: After I had the screen apart and back together again, but before reassembling the machine, I tested it. It worked, yay. I turned it off and started tidying things up for reassembly. Unfortunately, in my excitement to get it all back together again, I forgot to unplug the power and - inevitably - blew the backlight fuse on the motherboard. The fuse is a little green SMD thing with a 'P' on it, located to the right of the screen connector on the motherboard (annoyingly, slightly obscured by the magnesium frame). I tried to fix it 'properly', by soldering a new fuse on top of the blown one, but couldn't quite get it to stick. So I just put a blob of solder on top of the old fuse. Not ideal - there's no fuse now - but it works. (Until it doesn't.) Remember to unplug power and battery whenever you do anything with the motherboard, even just basic tidying up/reassembly! Also, I should really have done something about the noisy fan .

[mikemex]

Remember to unplug power and battery whenever you do anything with the motherboard, even just basic tidying up/reassembly!

My X301 has survived an incredibly large amount of careless treatment on my part. I once swapped the RAM while it was suspended. And it booted like nothing afterwards...

Don't do it at home.