yashsingh1/xdaforums huggingface dataset:
[Android Q&A, Help & Troubleshooting] Sam00r:
I've successfully used mine with a otg cable and USB hub at work. I actually use my tab as a citrix client with a real keyboard and mouse. Will that suffice? Just wondering if it'll work fine in Android but not in the UEFI menu.
[Android Q&A, Help & Troubleshooting] khanghua:
my OTG cables don't work so I will sit here and pray for you guys

... waiting for OTA
[Android Q&A, Help & Troubleshooting] Sam00r:
Did it work in android? Mine works fine in android, but doesn't work in the EFI shell at all. Tried with a powered USB hub, and straight to a keyboard and its a no go.

FYI rather than running efibootmgr from ADB, you can save yourself some time and use a terminal emulator on the tab with your keyboard/hub plugged in via OTG once you've transferred the binary.

Just run:

su
cd /data/local/tmp
./efibootmgr -n 0001
reboot

---------- Post added at 09:40 PM ---------- Previous post was at 09:36 PM ----------

I'm also curious as to what the difference between these OTG cables could be. They are only cables after all.

Hubs I can understand, I think my hub doesn't work because without it sensing a host on the other end, it powers down, and with the tab plugged in via OTG it doesn't power up.

It's a Belkin F5U307
[Android Q&A, Help & Troubleshooting] TommyDN:
Since efibootmgr is most probably linux microkernel based it has very few drivers for usb hosts and hubs built in the efi loader. (This is what im guessing it may not be true at all)

I don't think OTG cables make any difference since they are almost identical for every one of them (internally) ((could also be wrong on this)).
[Android Q&A, Help & Troubleshooting] Sam00r:
Ok so I've done some simple testing my end with my one and only OTG cable.

I hooked up a multimeter to the +5v and GND (Pins 1 and 4 on the Female end) and I get no current at all. So it seems you need a USB hub that either doesn't give a hoot about whether its getting any power from the host or not, or you can splice in your own 5v power supply. Going to give this a try now.
[Android Q&A, Help & Troubleshooting] social-design-concepts:
Well for otg cables there are three common types :

Most common is 0 ohms on the sense / id

There are some with 40 ohms on the sense / id

There are some with 100 ohms on the sense /id

If no one has been successful yet and their is an experienced user that what's to try something let me know, their could be an additional step needed but I didn't think it had anything to do with accessing the uefi setup but I could be wrong.

Also try using bootmanager -n 0002 first the first time accessing the setup successfully was with this option.

Also finger bashing f2 when powering on might help too.
[Android Q&A, Help & Troubleshooting] Sam00r:
Yep I was right.

Instead of splicing together a cable, I remembered I had a Mini USB cable with two male usb ends on it to power a 2.5" USB drive.

My USB hub has a MiniUSB port to the host, so I connected the data plug into the OTG, the Power plug into a 5v 500ma power adaptor and the mini usb into my hub.

I'm now into the setup.

Give me a few minutes and I'll take a photo of the whole setup.
[Android Q&A, Help & Troubleshooting] TommyDN:
This made it work for me too! this may be the solution here! :)
[Android Q&A, Help & Troubleshooting] Sam00r:
There you go.

Most people will probably need one of these http://www.amazon.co.uk/Male-Female-splitter-adapter-Cable/dp/B00NIH0RLE

I think I've managed to kill my tab now. I was trying to get windows 10 setup to boot, but blue screened at acpi_bios_error. For some reason I enabled fast boot by accident, now I can't get into the setup to change it as jt just flashes up with the Lenovo splash and then powers down before its even discovered the keyboard. I can get into the "starting fastboot" screen, but that's all.

I'll open an rma and hope they don't do any checks...
[Android Q&A, Help & Troubleshooting] social-design-concepts:
Try using clonezillia i386 if it trys to boot off the USB disk you can use efibootmanager to get back in
[Android Q&A, Help & Troubleshooting] Sam00r:
I know my USB hub at the office doesn't care about power input, it's always on whether its plugged into a host or not, this might work to get back into the setup, I'll give it a go in the morning.

---------- Post added at 11:06 PM ---------- Previous post was at 11:04 PM ----------

Downloading now. I still had the Windows 10 install USB plugged in and it didn't try to boot from that, but its worth a go.

How did you manage to get into the Windows installation? Were you using 64bit or 32? I tried 32 as I thought uefi on bay trail was limited to 32bit OS's.

---------- Post added at 11:17 PM ---------- Previous post was at 11:06 PM ----------

Nope, still the same. It hangs at the Lenovo screen for a bit longer, but doesn't init the keyboard.
[Android Q&A, Help & Troubleshooting] social-design-concepts:
I used 32bit Windows 10 I'll play around when I get home to see if I come up with anything. See if three button power on brings you to dnx mode.

Users beware be sure to disable fastboot.
[Android Q&A, Help & Troubleshooting] Sam00r:
Three button power on just gives me "Starting fastboot..." and if I plug it into a pc I do get an adb device, but adb doesn't list any devices.

It does show up in the Intel flashing software, but it can't partition it. Fastboot commands fail although it does see it.

Ughhh why did I enable fast boot:(
[Android Q&A, Help & Troubleshooting] social-design-concepts:
uefi fast boot is enabled by default, dnx fastboot mode only accepts two commands that I know of

fastboot flash loader loader.efi and fastboot boot fastboot.img

I've come across the dnx fastboot mode on a couple of windows 8 only tablets, Toshiba Encore 2 has the dnx fastboot mode so I imagine that there has to be away to either get the device back in android mode or some other provisioning mode from dnx fastboot i just got home guess its time to play for 20 minutes before bed.

I wonder if the esp.img can be flashed from this mode, hmm, hmm.
[Android Q&A, Help & Troubleshooting] Sam00r:
Possibly, if you could pull it from another tab that might work
[Android Q&A, Help & Troubleshooting] haerwu:
Fun. I used same OTG cable and other USB hub.

Combo works under Android just fine without providing extra power (wireless keyboard and yubikey plugged). To get it working in BIOS I needed to provide external power to the hub.
[Android Q&A, Help & Troubleshooting] haerwu:
Heh. Flipped 'UEFI Fastboot' one time too much ;(

No entry to setup + wrong boot mode == ;(
[Android Q&A, Help & Troubleshooting] Sam00r:
Yep, that's what must've happened. Did you do the same?
[Android Q&A, Help & Troubleshooting] Sam00r:
Basically the otg port won't provide power before the OS has booted. There is an option to change this in the bios, it's default is automatic though, so somethings overriding it.

Using the usb y-cable for extra power works great though.
[Android Q&A, Help & Troubleshooting] social-design-concepts:
UEFI fast boot being ENABLE - disables USB initialization, So the USB port are not active until the OS loads drivers.

Were you able to get back into the setup?
[Android Q&A, Help & Troubleshooting] Sam00r:
Nope, still stuck. I don't think it's charging either. Got a feeling it's now a paperweight. I'll send it off to Lenovo next week if I can't sort it out, it's a bit beyond me though.
[Android Q&A, Help & Troubleshooting] redxYu1825:
Permanent Recovery??

http://xdaforums.com/xperia-z/orig-development/app-recovery-twrp-2-4-3-0-lockled-t2190936

Try this it might work

I got my TAB back to school ROM

I might Do it today after school

:cowboy:
[Android Q&A, Help & Troubleshooting] Sam00r:
I highly doubt that'll work. It's for ARM, not Intel.
[Android Q&A, Help & Troubleshooting] Sam00r:
I've unhooked the battery to see if it'll reset the cmos.

I've also attached some photos of the board, if anyone spots a cmos reset, holla at me!
[Android Q&A, Help & Troubleshooting] TommyDN:
If it had a CMOS reset pin i would guess its under that shielding
[Android Q&A, Help & Troubleshooting] ormefocus:
Short the connection to the backup battery as well, bios resets, tablet boots.
[Android Q&A, Help & Troubleshooting] Sam00r:
I can't see a backup battery? I've shorted what I thought was a battery but I think it's actually the vibration motor.

I had the main battery unhooked for about 3 hours, gave it a try. No change.

I thought UEFI was stored in NVRAM though, so might not be a simple case of shorting a battery.

I don't really want to start lifting the board as there are warranty tabs over the screws and at the moment I haven't tripped anything that would be noticeable to Lenovo other than the bios setting which I'm hoping they won't check.
[Android Q&A, Help & Troubleshooting] haerwu:
http://www.myfixguide.com/manual/lenovo-tab-s8-50-teardown/ shows many photos of board but I did not notice any backup battery there.
[Android Q&A, Help & Troubleshooting] ormefocus:
Oh, weird, thought that was a battery. Well, I shorted something and the bios when back to default booting android. I did unhook the battery too, only for a few minutes.
[Android Q&A, Help & Troubleshooting] Sam00r:
Oh? Can you remember what you shorted? I assume you had the battery disconnected at the time?
[Android Q&A, Help & Troubleshooting] haerwu:
Disconnecting battery helped - tablet boots back into Android.

For how long? I left it for 10-15 minutes as had something other to do.
[Android Q&A, Help & Troubleshooting] Sam00r:
Minutes or hours? I've left it at my office over might with the battery disconnected.
[Android Q&A, Help & Troubleshooting] haerwu:
I had no idea that simple recovery is available.
[Android Q&A, Help & Troubleshooting] Minto107:
So you don't know how android updates via ota or you just have HTC ;) every phone has recovery but stock one is very limited and can flash only signed files. ClockWorkMod is just modified stock recovery that you can find in any Xperia, Samsung Galaxy, LG (?) phones ;)

Wysłane z mojego SM-N910C przy użyciu Tapatalka
[Android Q&A, Help & Troubleshooting] haerwu:
[MENTION=5387684]Minto107[/MENTION] I know what recovery is (never had HTC). Just remember all those posts that there is no recovery space on S8 and CWM one has to be run by tricks (which I did when bought tablet).
[Android Q&A, Help & Troubleshooting] Minto107:
Huh it has to have it if you can boot to recovery from Lenovo OTA app (there is boot to recovery option) so it has to have recovery and also where would temporary recovery be flashed?

Wysłane z mojego SM-N910C przy użyciu Tapatalka
[Android Q&A, Help & Troubleshooting] Sam00r:
Ok so the solution to this is to pop the back off using a plastic spudger, or a guitar pick etc. Disconnect the battery by unscrewing the small bracket and popping the ribbon off. Keep the screw and bracket somewhere safe. Leave something plastic or paper, card, anything between the connections to stop them touching.

Leave it like that over night, reconnect it in the morning and it should've reset the bios back to default.
[Android Q&A, Help & Troubleshooting] social-design-concepts:
Glad you got it back.
[Android Q&A, Help & Troubleshooting] haerwu:
Few minutes is enough.
[Android Q&A, Help & Troubleshooting] Sam00r:
It was disconnected for 3 hours which wasn't enough. Over night did it though.

Now I just need to get windows 10 installed. I got an acpi_bios_error last time I tried to boot the installation, need to work this out.
[Android Q&A, Help & Troubleshooting] TommyDN:
With a computer if you press the power button without any power connected it depletes all the current left in the circuits. Maybe trying to power on the tablet with the battery disconnected will fully deplete all the current that's still left in the circuits and quicken the process.
[Android Q&A, Help & Troubleshooting] social-design-concepts:
So has anyone made a thread for accessing the uefi setup yet? If not i'll setup a dev-db on the subject this weekend. The force factory defaults process would be a good thing to add to my instructions.
[Android Q&A, Help & Troubleshooting] TommyDN:
Lenovo changed the lollipop date to either never or a long time in the future.. :(

https://support.lenovo.com/us/en/documents/ht101396
[Android Q&A, Help & Troubleshooting] Sam00r:
I doubt I have access to the dev dB, I can do a writeup of our findings though.

---------- Post added at 03:41 PM ---------- Previous post was at 03:03 PM ----------

Doesn't really matter now it's been opened up. We could probably get a marshmallow rom running quicker than lienovo ever could.
[Android Q&A, Help & Troubleshooting] TommyDN:
I know but thought i'd post it here for the people that are not willing to unlock to UEFI
[Android Q&A, Help & Troubleshooting] social-design-concepts:
if you don't mind i'll start a dev-db for this tab on Sunday

we still have to tackle the issue of the bootloader being locked when in Android OS Mode or Set it to Windows 8.x Mode and completely re-partition the device.
[Android Q&A, Help & Troubleshooting] Sam00r:
Of course I don't mind, that'd be great if you get chance.

I think for most people, setting to Windows mode would suffice, although you'd basically need to treat it more like a quirky traditional x86 pc/laptop. We could then just install x86 android. Theoretically anyway.
[Android Q&A, Help & Troubleshooting] Sam00r:
How did you manage to boot windows setup? I can't get into it, I've tried windows 8.1 and windows 10 32 bit. 64bit doesn't even begin to load, as expected.

It just blue screens with acpi_bios_error
[Android Q&A, Help & Troubleshooting] evolutionisbad:
The update matrix note says TBA for lollipop.

https://support.lenovo.com/us/en/documents/ht101396
[Android Q&A, Help & Troubleshooting] ormefocus:
I get the same. Tried changing many setting in the bios, pretty much anything that said ACPI - still get the blue screen acpi_bios_error when trying to boot windows setup.
[Android Q&A, Help & Troubleshooting] Sam00r:
I'm just trying a USB stick made with rufus instead. If that fails, I'll see if deleting the partitions makes any difference.
[Android Q&A, Help & Troubleshooting] Hash.H:
I posted a thread on how to do it. Its just as complicated I guess....

http://xdaforums.com/general/general/how-to-access-bios-lenevo-tab-s8-50-t3221768

That's the post I put up, hopefully Lenovo gets their S**T together and decide to release an update. Should we sue them for false advertising, or maybe that's taking things a bit too far.

Thanks once again [MENTION=4821597]social-design-concepts[/MENTION] for your help, I was able to access the bios. all I have to do now is to get windows 10 on it.
[Android Q&A, Help & Troubleshooting] haerwu:
[MENTION=6102505]Hash.H[/MENTION] imho you should copy paste original post as it was more readable and had some warnings and useful info included.
[Android Q&A, Help & Troubleshooting] KainXSS:
I can't access usb on mine for some reason today, tried about 10 different cables and the tablet only charges in offmode, in android it refuses to do anything but OTG devices still work. can't connect with droidboot or adb either because its not detected.

any ideas, did not get into bios to change anything either.
[Android Q&A, Help & Troubleshooting] social-design-concepts:
I can't check because I forgot my tab s8 at work but I believe this was the guide I used.

https://ms-iot.github.io/content/en-US/win10/SetupMBM.htm

Navigate to Device Manager -> System Setup -> South Cluster Configuration -> LPSS & SCC Configuration

Set “LPSS PWM #1 Support” to Disable

Set “LPSS PWM #2 Support” to Disable
[Android Q&A, Help & Troubleshooting] TommyDN:
^^ for me those were already disabled, i get the acpi bios BSOD with them disabled too :(
[Android Q&A, Help & Troubleshooting] Hash.H:
I loaded up a version of windows 8.1 32 bit. I was able to get the windows logo and that spinning loading thing, but it fails to go past 20 seconds without giving me blue screen of death. It gives an error message, but it goes away to fast, making it hard to read.
[Android Q&A, Help & Troubleshooting] social-design-concepts:
I'll have to play tomorrow then I'm not the best at taking notes and I have about 50+ bookmarks of sites to go back through.
[Android Q&A, Help & Troubleshooting] haerwu:
Is there a way to disable certificate check in "windows 8.1" mode? I want to run Linux.
[Android Q&A, Help & Troubleshooting] social-design-concepts:
Navigate to Device Manager -> System Setup -> Boot -> UEFI Security Boot -> Disable

I've been using the Grub EFI loader from the Clonezilla i386 disk

It should be disabled by default was on mine.
[Android Q&A, Help & Troubleshooting] Sam00r:
Thanks, I've tried a few different things. Managed to require a battery disconnect twice.

At least I know now that it only needs to be disconnected for a few minutes as long as the connections aren't touching.
[Android Q&A, Help & Troubleshooting] Minto107:
So we have unlocked bootloader?? If yes so might I should start building CM12.1?

Wysłane z mojego Lenovo TAB S8-50L przy użyciu Tapatalka
[Android Q&A, Help & Troubleshooting] Sam00r:
In a sense. You'd have to basically treat it like a laptop that uses efi rather than fastboot or whatever it is that boots android.
[Android Q&A, Help & Troubleshooting] mustyrash:
http://androidcommunity.com/asus-fi...loader-unlock-utility-for-zenfone-2-20151015/

Zenphone 2, another Intel atom based device has an unlock bootloader utility. Any way we can use this with the s8-50?

Won't mind a Marshmallow rom.
[Android Q&A, Help & Troubleshooting] Minto107:
It depends if it also has fastboot/bios(UEFI or how it's called) if yes sure we can use it if not like Xperia phones so it's not possible. It doesn't depend on CPU as much

Wysłane z mojego SM-N910C przy użyciu Tapatalka
[Android Q&A, Help & Troubleshooting] social-design-concepts:
It can't be used ZF2 isn't full uefi, I haven't dug into the app yet but if it works like other newer Asus unlock apps it downloads the unlocked firmware from Asus MDM Server then flashes it to the device.
[Android Q&A, Help & Troubleshooting] thexfiles123:
I recently bought this tablet and I'm very happy, but there is one odd issue, whenever I have headphones or earphones plugged in and audio starts playing, I can hear an annoying thumping sound, this happens at the start of audio playback, not during, as in *play audio* "thumping noise", pause audio, play it again "thumping noise" then normal playback resumes, this is very annoying for me, I have the the latest updates from software update installed and this only happens with headphones or earphones plugged in not with speakers or at least I don't notice it with speakers

What can I do? Any one have any ideas?
[Android Q&A, Help & Troubleshooting] mustyrash:
Try different headphones. Turn off any EQ setting etc. Try a different media player.

If you're convicted that it's hardware then take it back to the store and see what they can do
[Android Q&A, Help & Troubleshooting] Lostlam:
Can't believe we're still none the wiser as to when it will eventually arrive. Poor from Lenovo.
[Android Q&A, Help & Troubleshooting] sirxdroid:
A $150 tablet is a disposable, not worth any updates, at least that's Lenovo's thinking. Look at the Moto E phone they released just a few months ago. They already said no updates to Android M and buyers are not happy.

In the Android world, the only things worth buying are Nexus devices if you care about monthly security updates and the latest OS for a couple of years.

This tablet was my only attempt at a non-Nexus device and it's been a big disappointment: poor battery, gets hot, wifi issues, etc. Never again. Fool me once ...
[Android Q&A, Help & Troubleshooting] Lostlam:
Nexus devices are definitely the way to go if you care about swift updates. My Nexus 7 2012 runs on newer firmware than most of my other devices.

I personally think the tablet is worth what I paid for it (£70), but some of the niggles have dampened my experience. This will probably be the last time I purchase something from Lenovo.
[Android Q&A, Help & Troubleshooting] TommyDN:
Took from the Lenovo forum thread.. again.
[Android Q&A, Help & Troubleshooting] emontes:
I just don't understand why they keep promising if they don't know they will be able to deliver it, doesn't make any sense.
[Android Q&A, Help & Troubleshooting] Yenupuri:
Whoa...thanks [MENTION=6215853]mclean36[/MENTION]. I Did not know that.
[Android Q&A, Help & Troubleshooting] Michael322:
Is the root working on S8-50L ??

Edit: working :)
[Android Q&A, Help & Troubleshooting] jazzespresso:
it should :good:
[Android Q&A, Help & Troubleshooting] bigl34461:
I can't install the update. I am rooted. Density is 320. Update fails every time. How do I unroot?
[Android Q&A, Help & Troubleshooting] lilhaiti:
Should only need to change your density back...your build.prop needs to be stock. I've heard that some people updated without unrooting
[Android Q&A, Help & Troubleshooting] Yenupuri:
Yup. You just need to restore your build prop. I think it was posted by someone earlier. No need to unroot. At least..that worked for me.

---------- Post added at 12:10 AM ---------- Previous post was at 12:08 AM ----------

Oops. That was in another thread. Here is a link http://xdaforums.com/showthread.php?p=58490890
[Android Q&A, Help & Troubleshooting] bigl34461:
How do I restore my build prop? I tried changing the density but the the update still fails. I'm on a stock firmware. I never flashed a custom rom. I only did root
[Android Q&A, Help & Troubleshooting] Yenupuri:
The link I posted was an answer to a very similar question. Read up mate. That thread addresses the issue. In the same thread... There were a few posts discussing why it fails as well. Sorry I couldn't be more elaborate ...1am and sleepy!
[Android Q&A, Help & Troubleshooting] Yenupuri:
[MENTION=1509148]bigl34461[/MENTION] were you able to update ?
[Android Q&A, Help & Troubleshooting] bigl34461:
help please

im stuck on the lenovo logo after trying to change the build prop. now im trying to use flash tool. not really sure what to do. I've downloaded all the required files. should i boot into recovery or fastboot? nothing happens when i try to flash the stock rom using flash tools
[Android Q&A, Help & Troubleshooting] bigl34461:
im stuck on the lenovo logo after trying to change the build prop. now im trying to use flash tool. not really sure what to do. I've downloaded all the required files. should i boot into recovery or fastboot? nothing happens when i try to flash the stock rom using flash tools
[Android Q&A, Help & Troubleshooting] pigenjosefine:
Is there anyone that have the "TABS8-50LC_141010" laying arround and could post it, the link in the orginal post dosn't work
[Android Q&A, Help & Troubleshooting] bigl34461:
Any ideas on why i cant get off the stuck boot logo? I tried flashing stock rom in,flash tools but it stays at 0%. While in flashtools it says reboot using adb cmd. Adb doesnt detect the device