Thinkpads Forum

In case anyone still needs it, here's the PDF for LP125WF2-SPB4.

Current shipping status for the kits:
Your item has been processed through a facility in MOSKVA PCI-21, RUSSIAN FEDERATION at 6:59 am on January 1, 2017.

UPDATE 4 January 2017, 7:39am EST
Russian Post
Awaiting for departure from Russia
01 January 2017, 06:59 102972, Mr Lts Vnukovo MMPO Tsekh-2

In other words, it's still stuck at the Moscow Vnukovo Airport
(PS: not your fault, Nitrocaster)

RealBlackStuff wrote: Current shipping status for the kits:
Your item has been processed through a facility in MOSKVA PCI-21, RUSSIAN FEDERATION at 6:59 am on January 1, 2017.

I'd suggest to use Russian Post website for tracking.

Some orders have been already delivered (Finland and Switzerland), so we should see first feedback soon.

>Awaiting for departure from Russia

Mine arrived to Sweden some days ago. I am still to pick it up, however. Will probably do that today.

Same here, arrived yesterday...

But I wasn't home so I need to pick it up (probably on the weekend)

Installed on x220, but might have fried something. The display worked completely for a while, then started blinking as if there was a bad contact. Now the backlight stays off. Interestingly, the stock display now has the same problem with the backlight. Data signal works however, so I can see a picture on both screens by illuminating them by other means.

I uninstalled the mod and I'm now trying to figure out the backlight issue using the stock display. I'm new with electronics (can barely use a multimeter), any tips how to troubleshoot?

With multimeter in diode mode, test both F2 and F6 fuses :
http://imgur.com/lo276jQ

If it doesn't beep / show 0, you blew a fuse. From the schematic :
F2 is FUSE-3A32V-17-GP
F6 is FUSE-D5A32V-12-GP

boutch55555 wrote:With multimeter in diode mode, test both F2 and F6 fuses :
http://imgur.com/lo276jQ

If it doesn't beep / show 0, you blew a fuse. From the schematic :
F2 is FUSE-3A32V-17-GP
F6 is FUSE-D5A32V-12-GP

That's X230 board. My guess is that F2 and F6 have nothing to do with the problem because the adapter board enables backlight when the display is active but there's no backlight control from the motherboard. That means the only possible fault could be backlight power (VBL20). It goes from VINT20 through the F1 fuse straight to the LCD connector.



edit: I'm wrong, that's not X230. Is that X220T? I definitely don't have this one.

Okay, tested all fuses around the LCD connector. It seems that F1 has blown. I'm going to get a new fuse and try again.

Thanks!

edit: The fuse blew probably because I once forgot to remove the battery before switching the LCD cables.

vade wrote:Okay, tested all fuses around the LCD connector. It seems that F1 has blown. I'm going to get a new fuse and try again.
Thanks!

Were you touching LCD connectors while the motherboard was connected to battery or AC power?

vade wrote:The fuse blew probably because I once forgot to remove the battery before switching the LCD cables.

You're lucky, because it could have been dead LVDS, dead DisplayPort, blown trace under the LCD connector or even dead PCH.

Russian Post is weird:

That's really strange!
I live only about 10 miles (16KM) from the Moscow Post Office!
http://moscowboro.com/index.php?id=10
https://en.wikipedia.org/wiki/Moscow,_Pennsylvania
I nearly bought a house there 9 years ago.
Wonder what would have happened if I had given you a Moscow address?

nitrocaster wrote:You're lucky, because it could have been dead LVDS, dead DisplayPort, blown trace under the LCD connector or even dead PCH.

It's good to know it could be worse. Now, before ordering a new fuse, how bad an idea would it be to temporarily bridge the F1 fuse to see if it's the only component that needs to be replaced? And, if I do that, and the backlight still doesn't work, are there any additional components to check?

Btw, the mod is a beautiful thing with a LP125WF2-SPB4. Definitely worth the money and the risk of installation mistakes.

vade wrote:

nitrocaster wrote:You're lucky, because it could have been dead LVDS, dead DisplayPort, blown trace under the LCD connector or even dead PCH.

It's good to know it could be worse. Now, before ordering a new fuse, how bad an idea would it be to temporarily bridge the F1 fuse to see if it's the only component that needs to be replaced? And, if I do that, and the backlight still doesn't work, are there any additional components to check?

Only as a temporary solution and if you won't plug/unplug any internal connectors (such as LCD connector) with battery or AC power attached.
F1 is fed by VINT20 which is a primary power rail. If it's present, you get a backlight.

Bridged the F1 fuse, backlight still doesn't work. Measured VLED as 20V on the LCD logic board, also the fuses there are OK.

vade wrote:Bridged the F1 fuse, backlight still doesn't work. Measured VLED as 20V on the LCD logic board, also the fuses there are OK.

That's worse than I expected. Check if PANEL_BKLT_CTRL and BACKLIGHT_ON are present on LCD connector.

Russian Post attempts second try:

nitrocaster wrote:Check if PANEL_BKLT_CTRL and BACKLIGHT_ON are present on LCD connector.

Measured the voltages, PANEL_BKLT_CTRL (pin 5) is 3.36 V and BACKLIGHT_ON (pin 4) is 0.002 V.

vade wrote:

nitrocaster wrote:Check if PANEL_BKLT_CTRL and BACKLIGHT_ON are present on LCD connector.

Measured the voltages, PANEL_BKLT_CTRL (pin 5) is 3.36 V and BACKLIGHT_ON (pin 4) is 0.002 V.

I assume you get these readings with stock display plugged in.
BACKLIGHT_ON goes from PMH and should be high when VGA_BLON (from PCH) is high. Can you check VGA_BLON?

Is it possible that the lid_switch (using F3 fuse) got damaged/loose after the LCD-swap?

RealBlackStuff wrote:Is it possible that the lid_switch (using F3 fuse) got damaged/loose after the LCD-swap?

But vade said he sees an image on the screen. It goes blank when you close the lid.

nitrocaster wrote:I assume you get these readings with stock display plugged in.

Measured while the stock screen was displaying a picture without backlight.

nitrocaster wrote:BACKLIGHT_ON goes from PMH and should be high when VGA_BLON (from PCH) is high. Can you check VGA_BLON?

Can't seem to find a spot to measure VGA_BLON. The x220 schematics associate J47 from PCH to VGA_BLON, so does this mean I need to find J47 on the mobo, and measure there?

RealBlackStuff wrote:Is it possible that the lid_switch (using F3 fuse) got damaged/loose after the LCD-swap?

Linux says ACPI lid state is open, and there is a picture on the display, only without backlight.

vade wrote: Can't seem to find a spot to measure VGA_BLON. The x220 schematics associate J47 from PCH to VGA_BLON, so does this mean I need to find J47 on the mobo, and measure there?

You can measure it on R194 (better) or on U39 (worse).
Also, you may want to check resistance from BACKLIGHT_ON to ground (with disconnected power). It should be ~64K.

R194 is 3.36 V. No resistance between BACKLIGHT_ON and ground.

vade wrote:No resistance between BACKLIGHT_ON and ground.

Is it shorted to ground? Check again with disconnected LCD.

nitrocaster wrote:Is it shorted to ground?

Yes, so it seems. I measured again to make sure I tested the right pin (4).

nitrocaster wrote:Check again with disconnected LCD.

Same result.

vade wrote:

nitrocaster wrote:Is it shorted to ground?

Yes, so it seems. I measured again to make sure I tested the right pin (4).

nitrocaster wrote:Check again with disconnected LCD.

Same result.

Looks like the PMH is damaged. That is the only thing that can short BACKLIGHT_ON to ground and on a known good board it's 64K to ground.

nitrocaster wrote:Looks like the PMH is damaged. That is the only thing that can short BACKLIGHT_ON to ground and on a known good board it's 64K to ground.

Uh oh, sounds like no more backlight with this mainboard. A new mainboard is perhaps a reasonable way to go at this point?

vade wrote:Uh oh, sounds like no more backlight with this mainboard. A new mainboard is perhaps a reasonable way to go at this point?

A reasonable way to go is to replace the PMH. Which CPU do you have on your board: i5 or i7?