Lenovo Thinkpad E15 Gen 2 NM-D011 - No display ? External , yes!

[AccountSaver]

Here is a pretty crazy one.

Step 1.
Laptop was brought to me as dead not working. Removed everything , cleared everything.
Step 2.
Some liquid damage close to the Type - C connector, and the connector even though it was cleaned wasn't charging the battery . Removed the Type-C port, and replaced it. Now the laptop turns on and charges battery. Shows external screen , not internal.
Step 3.
Took out the screen and checked it to a secondary Gen 2 i have, screen works like a charm.
Step 4.
Lets ,dive into the board. I see the edp cable on the side of the FPC connector (40pin) is a little bit damaged in the last 3 lanes like, blown ... I'm ordering a brand new. Install it . Again no image internally but only externally.
Step 5.
FPC connector shows a little bit dodgy ... let's replace it also . Brand new one connected, and secured. 100% . Again , no image...
Step 6.
Let's check the fuse next to the FPC connector, what do i see? It's blown. Let's replace it with the same one (32V/3A 0402 SMD Fuse)... replaced ,and still no image but at the same time dead laptop . I'm like what the hell ? So i remove the SMD Fuse, and replace it with another one fuse. Again laptop dead.... i remove the fuse laptop turns on.... but no image again.
Step 7.
Go back and forth , when connecting the EDP Cable to the screen laptop remains dead. If you remove the cable laptop turns on , but again no image. If you remove the fuse BUT install the display cable (edp) laptop turns on without image.

So something is going on ...with the "specific" place of the FUSE ,or anything..

It's a little bit , confusing ?!I would say... if you plug edp cable (with fuse installed) laptop doesnt even turn on ,remains dead, you remove either SMD fuse OR the Edp Cable, laptop works and goes to diagnostic with external monitor.

How the hell am i suppose to fix that ?

Thanks!

[m1ch43lzm]

Hi

Schematics here on post #9:
https://www.badcaps.net/forum/troubl...98#post1718498

Measure for resistance to GND on both sides of the fuse, with and without the LCD cable plugged in, you should have a high value of several Kohm

Check your soldering on the LCD connector

From the schematics on page 40, only pins 1 and 2 are the backlight voltage +LEDVDD after the fuse FG1, pin 3 is not connected on the LCD connector on the board (should measure OL on resistance to GND without the cable plugged in)

Please post close up pictures of the LCD connector area

[AccountSaver]

Hi

Schematics here on post #9:
https://www.badcaps.net/forum/troubl...98#post1718498

Measure for resistance to GND on both sides of the fuse, with and without the LCD cable plugged in, you should have a high value of several Kohm

Check your soldering on the LCD connector

From the schematics on page 40, only pins 1 and 2 are the backlight voltage +LEDVDD after the fuse FG1, pin 3 is not connected on the LCD connector on the board (should measure OL on resistance to GND without the cable plugged in)

Please post close up pictures of the LCD connector area

4.92mΩ on one side , and similar to the other side, with it increasing per second. When it's not connected the edp cable.

When it's connected , i get a beeping sound that it's connected to ground both sides.

Attaching photos:

[AccountSaver]

When cable is connected all go beep to ground all pins of the FPC connector

[Sephir0th]

Is it so hard to believe that either the cable or (meanwhile) the panel is shorted to GND on this track?

[AccountSaver]

Is it so hard to believe that either the cable or (meanwhile) the panel is shorted to GND on this track?

But both cable and screen got replaced.
Plus as i wrote , they are both tested on the same model (another machine) which i had laying around.

It's only being here ,the problem .

[m1ch43lzm]

Could it be a very tiny solder bridge here?

Add flux and touch the soldering iron to those pins, inspect carefully for solder bridges
While the solder joints on the cap and fuse look questionable, right now they "work", you really need to use more flux when soldering


From the schematics, pin 3 is not connected, pin 4 is GND, on the first picture, start counting the pins from right to left


The only possibility i can think, is that pins 1.2.3 are connected on the LCD cable side, yet on the board side only pins 1,2 are connected and pin 3 is NC

And you have shorted pins 3,4 on the board

With a sharp probe on your multimeter, test continuity from pin 3 (counting from right to left) to GND, it should read OL

Measure continuity of pin 1 to pin 3 on the cable to be sure

So, while plugging in the cable, pin 3 (shorted to pin4 on the MB, gets connected to pins 1,2 (by the cable)

[AccountSaver]

Could it be a very tiny solder bridge here?

Add flux and touch the soldering iron to those pins, inspect carefully for solder bridges
While the solder joints on the cap and fuse look questionable, right now they "work", you really need to use more flux when soldering


From the schematics, pin 3 is not connected, pin 4 is GND, on the first picture, start counting the pins from right to left


The only possibility i can think, is that pins 1.2.3 are connected on the LCD cable side, yet on the board side only pins 1,2 are connected and pin 3 is NC

And you have shorted pins 3,4 on the board

With a sharp probe on your multimeter, test continuity from pin 3 (counting from right to left) to GND, it should read OL

Measure continuity of pin 1 to pin 3 on the cable to be sure

So, while plugging in the cable, pin 3 (shorted to pin4 on the MB, gets connected to pins 1,2 (by the cable)

explaining to this much detail i believe it can help me out a lot like instructions left to right, count etc.
Thanks for taking the time, effort to write to me. I will try and report back what i see for sure.

I have used a lot of flux AMTECH etc. just to be sure that i can touch it up , and be sure for the connection , under the microscope also it 'doesn't show as not connected. But for sure i will try it out , i will remove it totally and start the ground up slowly .

[AccountSaver]

Could it be a very tiny solder bridge here?

Add flux and touch the soldering iron to those pins, inspect carefully for solder bridges
While the solder joints on the cap and fuse look questionable, right now they "work", you really need to use more flux when soldering


From the schematics, pin 3 is not connected, pin 4 is GND, on the first picture, start counting the pins from right to left


The only possibility i can think, is that pins 1.2.3 are connected on the LCD cable side, yet on the board side only pins 1,2 are connected and pin 3 is NC

And you have shorted pins 3,4 on the board

With a sharp probe on your multimeter, test continuity from pin 3 (counting from right to left) to GND, it should read OL

Measure continuity of pin 1 to pin 3 on the cable to be sure

So, while plugging in the cable, pin 3 (shorted to pin4 on the MB, gets connected to pins 1,2 (by the cable)

Okay so without the cable 4 pin is short to ground ,but 3 pin is NOT shorted to groud.
When i plug in either another screen or the old cable again it shows 3 + 4 pin short to ground.
So maybe there is another error somewhere else?

[m1ch43lzm]

Maybe you got the wrong cable for your laptop? Unless you can check with another laptop of the same model/type/same board number

I checked the schematics of another board NM-C421 (E14/E15 gen1), while the FPC connector is the same 40 pins, the pinout is completely different, starting with the first 4 pins are connected to the backlight voltage, that could explain it

You mentioned the old cable was burnt at the end, I wouldn't use it
I suggest visually checking the ends of both original and replacement cables under a microscope

[AccountSaver]

Maybe you got the wrong cable for your laptop? Unless you can check with another laptop of the same model/type/same board number

I checked the schematics of another board NM-C421 (E14/E15 gen1), while the FPC connector is the same 40 pins, the pinout is completely different, starting with the first 4 pins are connected to the backlight voltage, that could explain it

You mentioned the old cable was burnt at the end, I wouldn't use it
I suggest visually checking the ends of both original and replacement cables under a microscope

Yes, it's direct original replacement.
Yes, i already did that, until you wrote the message because i didn't know what to do .

It's Gen 2.This laptop.

Yes, the old one had a burn mark in the pin 1-2-3-4.
Yes,i tried the original also from the other laptop but again does the same, thing when the secondary laptop doesn't short.

My question to you ...

I have removed the screen and also checked the cable to the other laptop , and again turns on just fine.

Only to this laptop is the problem .

So i have pin pointed down the problem to the bridge...what i mean ? If i connect the cable then it becomes short to ground. If not, then it doesn't .. i mean if i dont' install the cable, even without the fuse it remains the same.

What could speak with 1-2-3-4 ,which controller that does that? Maybe the controller of the pins 1,2,3,4 is burned and problematic. So when you plug the cable, then it makes the chip to go short...

[m1ch43lzm]

There's 2 versions of the E15 gen2

According to Lenovo parts search

https://pcsupport.lenovo.com/us/en/p...isplay/buy-now

The models with Intel CPU (the one you have) (Type 20TD/20TE) uses display cable FRU: 5C10Z23917

The models with AMD CPU (type 20T8, 20T9) use a different display cable FRU: 5C10Z23842

They're not interchangeable, and that could explain it
I checked the schematics for NM-C771 (E15 gen2 AMD) and the pin out of the LCD connector is different, with pins 1-4 connected together

That's why I mentioned the "machine type" also needs to match, it's printed on the back cover

So I'm guessing you have an E15 gen2 AMD (the working laptop), and this one you are repairing E15 gen2 Intel and you're trying the screen/cable from the AMD laptop on the Intel one...

It's the first time I saw that a manufacturer uses different display cables but using the same chassis for the Intel/AMD versions, so you can't easily swap an Intel board with an AMD board or vice versa

[mcplslg123]

Post#12 should be seriously checked.Seems convincing answer for the problem being faced.

[m1ch43lzm]

I checked again the Lenovo parts website, and got this

https://pcsupport.lenovo.com/us/en/p...isplay/buy-now

Search for "edp" and I get 3 different cables for type 20TD (Intel)

CABLE FRU CABLE EDP CABLE RGB
Part No: 5C10Z23918

FRU CABLE EDP CABLE RGB TOUCH
Part No: 5C10Z23919

Mars1.0INTELFRUCABLEMars1.0IntelEDPCABLEIR
Part No: 5C10Z23917

The one with "touch" looks like it's for a laptop equipped with a touch screen, but the other 2 the difference is in "IR" or "RGB", whatever that means (and this one says Intel EDP cable)

But for the type 20T8 (AMD) i get this

https://pcsupport.lenovo.com/us/en/p...isplay/buy-now

FRU CABLE EDP RGB Cable
Part No: 5C10Z23842

CABLE FRU CABLE EDP IR Cable
Part No: 5C10Z23841

No touch screen option for the AMD version, again, different part numbers than the cables for the Intel version

Lenovo sure makes things confusing

[AccountSaver]

I checked again the Lenovo parts website, and got this

https://pcsupport.lenovo.com/us/en/p...isplay/buy-now

Search for "edp" and I get 3 different cables for type 20TD (Intel)

CABLE FRU CABLE EDP CABLE RGB
Part No: 5C10Z23918

FRU CABLE EDP CABLE RGB TOUCH
Part No: 5C10Z23919

Mars1.0INTELFRUCABLEMars1.0IntelEDPCABLEIR
Part No: 5C10Z23917

The one with "touch" looks like it's for a laptop equipped with a touch screen, but the other 2 the difference is in "IR" or "RGB", whatever that means (and this one says Intel EDP cable)

But for the type 20T8 (AMD) i get this

https://pcsupport.lenovo.com/us/en/p...isplay/buy-now

FRU CABLE EDP RGB Cable
Part No: 5C10Z23842

CABLE FRU CABLE EDP IR Cable
Part No: 5C10Z23841

No touch screen option for the AMD version, again, different part numbers than the cables for the Intel version

Lenovo sure makes things confusing

I am not sure. hahahah!

Both laptops are Intel ones. Both laptops are non-touch versions.

My cable the new that i have in front of me: Lenovo Thinkpad E15 Gen 2 LCD Video Cable DC02C00LD00

But i keep believing that something is wrong with the "pins all together" i mean the 4 pins that are getting their signals most probably from another controller chip ?

[AccountSaver]

There's 2 versions of the E15 gen2

According to Lenovo parts search

https://pcsupport.lenovo.com/us/en/p...isplay/buy-now

The models with Intel CPU (the one you have) (Type 20TD/20TE) uses display cable FRU: 5C10Z23917

The models with AMD CPU (type 20T8, 20T9) use a different display cable FRU: 5C10Z23842

They're not interchangeable, and that could explain it
I checked the schematics for NM-C771 (E15 gen2 AMD) and the pin out of the LCD connector is different, with pins 1-4 connected together

That's why I mentioned the "machine type" also needs to match, it's printed on the back cover

So I'm guessing you have an E15 gen2 AMD (the working laptop), and this one you are repairing E15 gen2 Intel and you're trying the screen/cable from the AMD laptop on the Intel one...

It's the first time I saw that a manufacturer uses different display cables but using the same chassis for the Intel/AMD versions, so you can't easily swap an Intel board with an AMD board or vice versa

my laptop (The broken ) exact details are:

PF-3JCYGJ 20TD-00GNUK 2022/01

[m1ch43lzm]

Google search brings me this Ebay listing

Screen Display Cable IR For Lenovo ThinkPad E15 Gen 2 5C10Z23841 DC02C00LD00

According to part number, that cable is for the AMD version...

You got the wrong cable, you need to get one suitable for type 20TD that would be:
5C10Z23917

(Image taken from Lenovo parts site, cropped the relevant portion)
It says "GE5B0 EDP CABLE IR INTEL DC02C00MF10"
Perhaps the IR means for an IR camera? (As in, for face id/windows hello)
The other cable 5C10Z23918 I guess is for a regular webcam

But i keep believing that something is wrong with the "pins all together" i mean the 4 pins that are getting their signals most probably from another controller chip ?

The pins are connected together on the cable itself, so plugging in the cable without the screen attached to it would cause the short

Could it be, that your customer (or someone else) replaced the LCD cable with the wrong type, causing the burn on the cable and a possible short on main rail, then brought the laptop to you for repair and the liquid damage on the usb-c port was a secondary fault?

[AccountSaver]

Google search brings me this Ebay listing

Screen Display Cable IR For Lenovo ThinkPad E15 Gen 2 5C10Z23841 DC02C00LD00

According to part number, that cable is for the AMD version...

You got the wrong cable, you need to get one suitable for type 20TD that would be:
5C10Z23917

(Image taken from Lenovo parts site, cropped the relevant portion)
It says "GE5B0 EDP CABLE IR INTEL DC02C00MF10"
Perhaps the IR means for an IR camera? (As in, for face id/windows hello)
The other cable 5C10Z23918 I guess is for a regular webcam


The pins are connected together on the cable itself, so plugging in the cable without the screen attached to it would cause the short

Could it be, that your customer (or someone else) replaced the LCD cable with the wrong type, causing the burn on the cable and a possible short on main rail, then brought the laptop to you for repair and the liquid damage on the usb-c port was a secondary fault?

Yes, you are right most probably it was changed, before it came to my hands and that's why it was burned those lines.

I have just placed an order from eBay (China} so it will take 2-3 weeks to arrive , the correct part number as shown from lenovo (yours) .

So i believe this time it will just be fixed.

If not, i will just jump out of the window...

[AccountSaver]

Google search brings me this Ebay listing

Screen Display Cable IR For Lenovo ThinkPad E15 Gen 2 5C10Z23841 DC02C00LD00

According to part number, that cable is for the AMD version...

You got the wrong cable, you need to get one suitable for type 20TD that would be:
5C10Z23917

(Image taken from Lenovo parts site, cropped the relevant portion)
It says "GE5B0 EDP CABLE IR INTEL DC02C00MF10"
Perhaps the IR means for an IR camera? (As in, for face id/windows hello)
The other cable 5C10Z23918 I guess is for a regular webcam


The pins are connected together on the cable itself, so plugging in the cable without the screen attached to it would cause the short

Could it be, that your customer (or someone else) replaced the LCD cable with the wrong type, causing the burn on the cable and a possible short on main rail, then brought the laptop to you for repair and the liquid damage on the usb-c port was a secondary fault?

The camera of the laptop is not IR i believe this is the part number :
sc20f27116
fw6624-222 1aec

[m1ch43lzm]

https://pcsupport.lenovo.com/id/en/p.../display/model
According to the full model 20TD00GNUK i get only these options, you can enter the serial number at that web site to get the exact parts used

Mars1.0INTELFRUCABLEMars1.0IntelEDPCABLEIR
Part No: 5C10Z23917

Camera,HD-IR,Front,2MIC,ZIF,Azw
Part No: 5C20W42992
Substitutes: 5C20W42993 and 5C20W42994

And it says exactly what you posted SC20F27116 (for 5C20W42993), so it's an IR webcam, on the regular 720p cameras if i select only 20TD the number on the sticker is completely different

You can click on the images on the lenovo parts site and check