Touchscreen stops working right after boot in LineageOS 21

[senseamidmadness 8]

Hey folks,

 

I'm having a weird problem. I was able to successfully flash LineageOS 21 onto my Pro1X, but about a minute after booting (may be when the screen first locks, not sure) the touchscreen quits working and doesn't work again unless Recovery and the Lineage package are totally reflashed. I reflashed them using fastboot.

Tried all four of the currently-available nightly builds and all four of them did the same thing. Even tried installing the oldest one and updating within Lineage to the latest. Same problem.

I can do some limited navigation with the keyboard but obviously it's not usable as a phone in this state.

I did check and the touchscreen worked in stock Android before the flash.

 

Any ideas?

 

Also is it normal for both the "model" string and serial number to be mismatched in the bootloader? My model is listed as "bengal" and my serial number is hexadecimal while the one on the back of the phone is alphanumeric. This is a significant problem as that mismatch means the "return to stock" script won't work -- it expects the model string to return as "QX1050".

[EskeRahn 5,455]

20 hours ago, senseamidmadness said:

Also is it normal for both the "model" string and serial number to be mismatched in the bootloader? My model is listed as "bengal" and my serial number is hexadecimal while the one on the back of the phone is alphanumeric. This is a significant problem as that mismatch means the "return to stock" script won't work -- it expects the model string to return as "QX1050".

AFAIK that is normal

[senseamidmadness 8]

Appreciate that info. Anybody know how to un-break the "return to stock" script that's on this forum by replacing the expected QX1050 with "bengal"?

[senseamidmadness 8]

Okay, I was able to follow a tutorial on this forum and get stock Android reflashed on this phone - the 2020/07/07 build version 2.1.2. Touchscreen still isn't working. I'm wondering if it might be a hardware issue with the digitizer or something at this point.

 

Should I order a replacement screen maybe?

[EskeRahn 5,455]

2 hours ago, senseamidmadness said:

Should I order a replacement screen maybe?

A long shot is that it is a cable that is not firmly in the plug, so if you are to open the upper part with the intend of replacing anyway then try to check that.

[senseamidmadness 8]

I ordered a screen as a well-reviewed supplier on AliExpress had them for only $50. Will update when I receive it in the mail in a few weeks and open up the phone.

[senseamidmadness 8]

Replacement screen hasn't arrived yet, but after a few days of staying off on the shelf the phone has...somehow got its touchscreen functionality back in stock Android 11. Don't know for how long. I'm going to open it up anyways but this is super weird.

 

Screen firmware updating itself maybe?

 

Edit: it did the same thing it did in LineageOS. Worked for a little bit longer this time, about 5 minutes, and now the screen won't respond to touch again. Gotta be a hardware issue right?

Edited September 2 by senseamidmadness

[EskeRahn 5,455]

2 hours ago, senseamidmadness said:

Gotta be a hardware issue right?

That would be my guess too, but strange that that it starts working again though shortly. If you are lucky, it is a cable not locked in the connector and maybe the way holding it can make the cable just get or just loose contact BUT this is a pure guess,

[Burkhard 3]

Hello,

I always read here with great interest. I also have a pro1x and am slowly getting used to it. I use it as a normal phone with Android. 
Since there seem to be more problems, I would like to order some spare parts just to be on the safe side. But when I search for pro1x on Aliexpress, I don't get any hits. Can you give me some tips, links. Here or as a PM, if that's possible?

Thanks,

sorry, I still have to learn here in the forum

Burkhard

[EskeRahn 5,455]

The screen is identical to the one used by Elephone U Pro.

BUT there could be some initialisation issues with setting the size of the touch border, that we are yet to find a solution for. Currently the only way I know of to do it, is to attach it to a pro1 (not pro1X) and re-flash that with stock android, as this process initialise the screen setup also.... (I have not tried this myself yet though)

Unfortunately none have (yet?) been able to extract what this precisely does, so it could be replicated directly on a Pro1X

So would be great if some had the skills and time to reverse engineer here....

[FlyingAntero 869]

7 hours ago, EskeRahn said:

Unfortunately none have (yet?) been able to extract what this precisely does, so it could be replicated directly on a Pro1X

So would be great if some had the skills and time to reverse engineer here....

Someone brave should test to flash stock Android 9 firmware of Pro1 to Pro1-X with new screen. I mean the same process that Lineage OS users have done when changing the screen.

"You have your current rom installed and try to overwrite it without wiping data. The installation starts and fails after a few minutes, however the display area is reconfigured"

It works on Pro1 and you do not lose data. But probably the flashing of Pro1 firmware to Pro1-X does not even start. And if it does, there might be high risk to brick device.

[senseamidmadness 8]

On 9/2/2024 at 2:47 PM, EskeRahn said:

That would be my guess too, but strange that that it starts working again though shortly. If you are lucky, it is a cable not locked in the connector and maybe the way holding it can make the cable just get or just loose contact BUT this is a pure guess,

I found a possible correlation between the phone's temperature and whether the touchscreen works or not, as it has sat in sleep mode for a few days now and the touchscreen seems to be working every time I grab it. Phone has consistently been at room temperature every time I've tried. But when I plug the phone in and charge it, after a minute or two it warms up a bit to the touch...and the screen won't receive any touch input. It's wacky.

A loose cable does seem possible, especially on the motherboard side. I'm still waiting on that replacement screen.

 

On 9/3/2024 at 2:07 AM, Burkhard said:

But when I search for pro1x on Aliexpress, I don't get any hits.

I searched "QX1050" and that found the screen I needed.

[Burkhard 3]

hello and thanks for the tip. the dealer has the same display for qx1050 and qx1000, so pro1x and pro1 on offer. but he doesn't ship to Germany, well, everything works fine. I just wanted to be on the safe side,

burkhard

[EskeRahn 5,455]

As mentioned you could also look for "Elephone U Pro" i think they are more common, and they use the same BOE display.

[FlyingAntero 869]

I think that this is best option since it includes correct frame.

https://www.aliexpress.com/item/1005005062900944.html

[Hook 3,015]

1 hour ago, FlyingAntero said:

I think that this is best option since it includes correct frame.

https://www.aliexpress.com/item/1005005062900944.html

I was under the impression that the frame for the Pro1 is not 100% identical to the frame for the Pro1x  (different camera?  Other subtle differences?).  Anyone know.  I can't remember.

[EskeRahn 5,455]

Ah yes, for the elephone ones you should get it without the frame, as it is different. If you can get it with a frame fitting the pro1/prpo1x, that is obviously easier to swap.

[FlyingAntero 869]

1 hour ago, Hook said:

I was under the impression that the frame for the Pro1 is not 100% identical to the frame for the Pro1x  (different camera?  Other subtle differences?).  Anyone know.  I can't remember.

I was thinking that they are the same. Is the selfie camera different? I thought that only rear camera is different.

But anyway, maybe @gusscan confirm? I think guss ordered pro1 screen panel with frame for Pro1-X.

Also, some sellers list same screen for both Pro1 and Pro1-X (see attachments).

 

[Hook 3,015]

1 hour ago, FlyingAntero said:

I was thinking that they are the same. Is the selfie camera different? I thought that only rear camera is different.

But anyway, maybe @gusscan confirm? I think guss ordered pro1 screen panel with frame for Pro1-X.

Also, some sellers list same screen for both Pro1 and Pro1-X (see attachments).

 

That's good news then.

[claude0001 1,337]

4 hours ago, FlyingAntero said:

I was thinking that they are the same. Is the selfie camera different?

I once tried to swap-in the screen assembly of a Pro1-X into a Pro1. They fit mechanically and connector-wise. The result was that the Pro1 was able to boot into a (working) Lineage recovery, but not into the full OS. I thus assumed the selfie camera was different.

Of course, the top half of the Pro1(X) includes more than the (touch)screen and camera. There is the indicator LED, the ambient-light photodiode, a speaker and (I guess) a mic for handheld audio. But somehow I had assumed those were analogue devices that could not cause a crash upon boot.

[EskeRahn 5,455]

I would expect that the screen plus frame they are selling, are far from the full top half, and thus not includes the front camera.

[FlyingAntero 869]

50 minutes ago, EskeRahn said:

I would expect that the screen plus frame they are selling, are far from the full top half, and thus not includes the front camera.

Yeah, the screen with frame does not include front camera module and the board for the connector. So those parts would need to swap anyway from the old screen. But the frame and the panel itself is the same so it makes the change much easier.

[senseamidmadness 8]

Update for y'all. I managed to get a replacement screen assembly straight from f(x)tec after back and forth messaging with their support. It even has a blue bezel. The one from AliExpress showed up and there's a notable difference: a small circuit board that connects from the body ribbon cable (2 plugs) to the display ribbon cable (1 plug) is missing in the AliExpress display and present in the OEM f(x)tec display.

 

I tried swapping the screen using the OEM one. Did the exact same thing as it always did. Touchscreen worked for a few seconds, plugged the phone in, then it stopped working.

Decided to open up the phone to see if it might be the ribbon cable plug on the motherboard. I've got a decent tool kit and some experience working on phones (and a ton working on desktops and laptops).

Noticed in a few places that things didn't look quite right. A screw was missing from the main body, underneath the back part of the screen, but its hole had been covered up by a little sticker anyway. There were weird wrinkles in the stick-on EFI shield tape atop the big chips and battery as if someone had attempted to peel it up and stopped. At least one of the body screws seemed suspiciously loose.

Got deep enough to unplug the whole series of ribbon cables on the mainboard and firmly reseat them.

 

After reassembly, no change. So whatever the hell's going on has to be something wrong with the mainboard or ribbon cable, or something someone else did when poking around inside this phone, and I don't feel like diagnosing this thing by replacing parts further. I'm just going to sell it for parts. I already bought another one in black that fully works so that'll be my new phone and I have a couple spare screens in case I ever break any.

 

Either the Ebay seller I bought it from lied to me about it being straight out of the Kickstarter box, or this one was a hack job from the factory. Either seems possible.

[senseamidmadness 8]

F(x)tec has been surprisingly communicative over email. They also sent me a replacement display cable after the display swap didn't fix it, and I'm going to try installing that.