[Help] Screen Artifacts - Is this normal? Techlast T20 [Video] - Android Q&A, Help & Troubleshooting

Hi All,
Have Purchased a Teclast T20 android tablet and while setting it up I thought of running a screen test.
Noticed those lines appearing randomly, after I saw that, I also noticed them showing in one or two apps (KOReader, some news app etc).
Video here: https://streamable.com/ukmn3
Is this caused by the GPU? does it mean device is defective (hardware) or is this something that can be fixed by software?
Thanks!

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Does anyone know if this can be fixed?

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tibrocks said:
Does anyone know if this can be fixed?
Click to expand...
Click to collapse
I had screen tearing, when scrolling pages. Also games ran very slow and stuttered. I then noticed that my T20 hardware revision was the T2E2, yet the preloaded Android build was for the T2E1. After a very long and tedious process of trying to sign up to the Chinese Baidu cloud storage, I was eventually able to download the official stock ROM for the T2E2 revision (also a VERY slow download < 100 KB/sec).
After reflashing my Teclast T20 with new T2E2 ROM, my screen tearing is now FIXED! Tablet also runs overall a lot smoother. And games run at normal speed.
I uploaded the ROM, repackaged with 7-Zip to save space - also renamed the Chinese folders in English, to my OneDrive for safe storage, since it is such an ordeal downloading from the official source. You are welcome to grab a copy, if you also have the T2E2 and need this ROM. Cheers.
T20 (T2E2)-Android7.1.1_V1.02.7z
https://1drv.ms/u/s!Ak1oNu4Puqijg6ZbbpbN-TGJ0Pxkmw

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parasupaman said:
I had screen tearing, when scrolling pages. Also games ran very slow and stuttered. I then noticed that my T20 hardware revision was the T2E2, yet the preloaded Android build was for the T2E1. After a very long and tedious process of trying to sign up to the Chinese Baidu cloud storage, I was eventually able to download the official stock ROM for the T2E2 revision (also a VERY slow download < 100 KB/sec).
After reflashing my Teclast T20 with new T2E2 ROM, my screen tearing is now FIXED! Tablet also runs overall a lot smoother. And games run at normal speed.
I uploaded the ROM, repackaged with 7-Zip to save space - also renamed the Chinese folders in English, to my OneDrive for safe storage, since it is such an ordeal downloading from the official source. You are welcome to grab a copy, if you also have the T2E2 and need this ROM. Cheers.
T20 (T2E2)-Android7.1.1_V1.02.7z
https://1drv.ms/u/s!Ak1oNu4Puqijg6ZbbpbN-TGJ0Pxkmw
Click to expand...
Click to collapse
Cheers mate, this is helpful!
I get screen tearing when scrolling pages as well - the only thing is, I don't know how to check the hardware version?
Settings > About screenshot attached
PS. did you have any issues charging? mine seems to charge slowly, I am waiting for an USB voltage/amp meter to find out what's going on

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tibrocks said:
Cheers mate, this is helpful!
I get screen tearing when scrolling pages as well - the only thing is, I don't know how to check the hardware version?
Settings > About screenshot attached
PS. did you have any issues charging? mine seems to charge slowly, I am waiting for an USB voltage/amp meter to find out what's going on
Click to expand...
Click to collapse
Sorry for the late reply. Been busy moving interstate.
You will notice in the attached screenshot, that my Android version now shows T20(T2E2) under Model, which now matches my hardware revision. Even though your screenshot does not show T2E1 anywhere on your Status page, the fact that you are running Build number 1.16, means it is the Android software build for the T2E1. I'm guessing that they simply did not bother displaying the hardware revision T2E1 for the first revision.
You can double check your hardware revision, by looking on the rear of your T20 Tablet. If you have a T2E2 hardware revision, then you probably have the same issue I had, with the mismatched software/hardware.
Otherwise, if you have the T2E1 hardware revision, I know that there is a later version of Android available for the T2E1, version/build 1.23, which you can try.
Also, sorry, not sure about charging. I have only left mine to charge overnight, so don't know how long mine takes to charge.

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parasupaman said:
You can double check your hardware revision, by looking on the rear of your T20 Tablet. If you have a T2E2 hardware revision, then you probably have the same issue I had, with the mismatched software/hardware.
Click to expand...
Click to collapse
Thank you sir!
Indeed, on the back of the tablet says T2E2 so wrong firmware as you mentioned.
Thanks for putting the files together - had an exceptional situation with this tablet!
TL;DR: I have no idea how I updated the firmware?!
So I installed Mediatek Driver provided and was following the Upgrade Tutorial pdf, loaded the Download Agent and Scatter-loading agent into the flash tool on my PC.
Tablet was connected via USB, android debugging switched on.
Got stuck at step 8 when trying to install the driver for MT65xx Preloader: This wouldn't show with the tablet ON, regardless of Debug setting.
Translated the guide and says Tablet OFF>connect USB - still not showing so I press Volume + on tablet..
On the computer I didn't get anything but tablet went into Boot Mode - I selected Normal: took some 3 minutes to boot and Voila! Fresh Android in Chinese, all my data gone.. ?!
On the tablet there were a few new Chinese apps that didn't look familiar - went to Settings trying to change language to English and also checked Android Info out of curiosity..
It now says T2E2!
I didn't 'flash' this via the PC.. so how did that happen? Is it possible the the T2E2 firmware was actually preloaded on the tablet?
Doing some checks now..
Thanks!

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tibrocks said:
Thank you sir!
Indeed, on the back of the tablet says T2E2 so wrong firmware as you mentioned.
Thanks for putting the files together - had an exceptional situation with this tablet!
TL;DR: I have no idea how I updated the firmware?!
So I installed Mediatek Driver provided and was following the Upgrade Tutorial pdf, loaded the Download Agent and Scatter-loading agent into the flash tool on my PC.
Tablet was connected via USB, android debugging switched on.
Got stuck at step 8 when trying to install the driver for MT65xx Preloader: This wouldn't show with the tablet ON, regardless of Debug setting.
Translated the guide and says Tablet OFF>connect USB - still not showing so I press Volume + on tablet..
On the computer I didn't get anything but tablet went into Boot Mode - I selected Normal: took some 3 minutes to boot and Voila! Fresh Android in Chinese, all my data gone.. ?!
On the tablet there were a few new Chinese apps that didn't look familiar - went to Settings trying to change language to English and also checked Android Info out of curiosity..
It now says T2E2!
I didn't 'flash' this via the PC.. so how did that happen? Is it possible the the T2E2 firmware was actually preloaded on the tablet?
Doing some checks now..
Thanks!
Click to expand...
Click to collapse
It looks like you managed to successfully flash the new firmware. The new firmware is Chinese (but supports English no problem).
I discovered that the weird way our Tablets are flashed, is that once you hit the 'flash' button in the SP Flash Tool, you then connect your tablet via USB cable in the OFF state (not turned on)], which starts the flash.
I have found that the new firmware fixes the screen tearing and definitely improves smoothness. However, I notice that the scrolling frame rate still drops (stutters) while touching the screen and performing scrolls and swipes. Frame rate seems to improve (smoothen) once the finger is lifted off the screen. I am hoping a future firmware update (hopefully soon) will fix this issue.

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parasupaman said:
I discovered that the weird way our Tablets are flashed, is that once you hit the 'flash' button in the SP Flash Tool, you then connect your tablet via USB cable in the OFF state (not turned on)], which starts the flash.
I have found that the new firmware fixes the screen tearing and definitely improves smoothness. However, I notice that the scrolling frame rate still drops (stutters) while touching the screen and performing scrolls and swipes. Frame rate seems to improve (smoothen) once the finger is lifted off the screen. I am hoping a future firmware update (hopefully soon) will fix this issue.
Click to expand...
Click to collapse
Yes flashing was weird, I didn't expect that?!
Seems like the update fixed the screen artifacts which is great!
Thanks

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tibrocks said:
PS. did you have any issues charging? mine seems to charge slowly, I am waiting for an USB voltage/amp meter to find out what's going on
Click to expand...
Click to collapse
Good to hear your T20 is now working better :good:
Also, I noticed that charging while the T20 is ON is VERY slow. However, charging while OFF is quite fast. I use the included USB cable, plugged into an AUKEY Quick Charge 3.0/2.0 charger. Not sure if it is compatible with MTK Pump Express, but my tablet seems to still charge pretty fast when OFF and connected to this charger.

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T2E2 with build V1.02_20181206
parasupaman said:
Sorry for the late reply. Been busy moving interstate.
You will notice in the attached screenshot, that my Android version now shows T20(T2E2) under Model, which now matches my hardware revision. Even though your screenshot does not show T2E1 anywhere on your Status page, the fact that you are running Build number 1.16, means it is the Android software build for the T2E1. I'm guessing that they simply did not bother displaying the hardware revision T2E1 for the first revision.
You can double check your hardware revision, by looking on the rear of your T20 Tablet. If you have a T2E2 hardware revision, then you probably have the same issue I had, with the mismatched software/hardware.
Otherwise, if you have the T2E1 hardware revision, I know that there is a later version of Android available for the T2E1, version/build 1.23, which you can try.
Click to expand...
Click to collapse
Hi, I just got my new T20 from aliexpress, and it shows "T2E2" on the back, but shows "T20" in status page, without the additional info....the build # says "V1.02_20181206", which seems like your same build , only a few weeks newer (dec 6th instead of nov).
I don't see any screen tearing, but I do notice low frame rates when playing average games like Marvel Contest Of Champions. During fights, it stutters, giving me worse performance than the 2014 Oneplus one that i used for this game previously.
I tried forcing GPU rendering under developer options, but it doesn't help. Is there anything I can do to increase the game performance? That's the whole reason I bought this tablet.
Would it help to try a custom ROM that's Android 8? Or is this a GPU problem that can't be fixed, unless they revise the firmware, which is very unlikely?
Any advice would be great, thx.

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Epiclectic said:
Hi, I just got my new T20 from aliexpress, and it shows "T2E2" on the back, but shows "T20" in status page, without the additional info....the build # says "V1.02_20181206", which seems like your same build , only a few weeks newer (dec 6th instead of nov).
I don't see any screen tearing, but I do notice low frame rates when playing average games like Marvel Contest Of Champions. During fights, it stutters, giving me worse performance than the 2014 Oneplus one that i used for this game previously.
I tried forcing GPU rendering under developer options, but it doesn't help. Is there anything I can do to increase the game performance? That's the whole reason I bought this tablet.
Would it help to try a custom ROM that's Android 8? Or is this a GPU problem that can't be fixed, unless they revise the firmware, which is very unlikely?
Any advice would be great, thx.
Click to expand...
Click to collapse
Hi. Looks like the correct firmware build :good: albeit with a slight date update.
I am definitely a little disappointed with game performance. I know that the T880 not a super powerful GPU. But I believe that the T20 is still underperforming due to the Android OS not being optimized for the Helio X27 CPU and T880 GPU. Raw benchmarks of the Helio X27/T880 GPU suggest we should be getting much higher frame rates in games than we are seeing on the T20. Really hoping they provide a firmware update (hopefully Oreo) to take advantage of the Helio X27 better. I notice that the T10 received several updates over a few months, after initial release. So I'm hoping that the T20 gets similar treatment and we see at least a couple of firmware updates at some point.
But yeah, I have been sticking to my Nintendo Switch for gaming, since the T20 has been pretty subpar for gaming. Even my Xiaomi Mi Max Pro (original) with a Snapdragon 652 processor, blows my T20 with Helio X27 out of the water. T20 has been ok for most things other things though. Although, the fact that videos play back with an ever so slight stutter, suggest that the software/drivers are definitely not in sync with the GPU. The hardware video decoding on the Helio X27 should make all video playback buttery smooth.

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parasupaman said:
I had screen tearing, when scrolling pages. Also games ran very slow and stuttered. I then noticed that my T20 hardware revision was the T2E2, yet the preloaded Android build was for the T2E1. After a very long and tedious process of trying to sign up to the Chinese Baidu cloud storage, I was eventually able to download the official stock ROM for the T2E2 revision (also a VERY slow download < 100 KB/sec).
After reflashing my Teclast T20 with new T2E2 ROM, my screen tearing is now FIXED! Tablet also runs overall a lot smoother. And games run at normal speed.
I uploaded the ROM, repackaged with 7-Zip to save space - also renamed the Chinese folders in English, to my OneDrive for safe storage, since it is such an ordeal downloading from the official source. You are welcome to grab a copy, if you also have the T2E2 and need this ROM. Cheers.
hola me podrias decir los pasos que has seguido para flashear la room?
gracias
Click to expand...
Click to collapse

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Please, send me accessibility to firmware. Thanks