Tesla

@yellowzelo thanks for the upload.

I'll give it a try and see how it goes with nvidia cards.

Update:

I've got the same symptoms that @Andrew54 got.

Adapter connected, no gpu: laptop boots to win10 successfully.

Adapter connected, w/ nvidia gpu:  boots to this error msg "Second Vga module is not suitable to this produce. Power off and remove it"

Hot plugging the gpu did not work.

Ive created an international qq account. however I am not able to use it to login or create an account on it168.com

that is exactly where i got stuck last time 

@ManyStrongWords I found 1.05 on a chinese website, but I couldnt download it.

and yeah, it has a good chance to work with bios v1.05 or 1.07.

1.05 is available on this website http://ideapad.it168.com/thread-5599091-1-1.html.

i tried it with 2.07 and 3.05 using nvidia card.

didnt make any difference to me. same behavior.

hey Gerald, thanks for taking time to test it out, I've done some extensive research on why nvidia cards wont work. and I've came to realize that bios is blocking them.

so in bios 2.07 and 2.04 the bios will just block nvidia gpus(they probably designed it that way so ppl dont plug other ultrabay cards) .

well, in bios v3.05/3.08, they have extended that blacklist to include anything connected to the ultrabay slot including amd cards where it will give you "unauthorized slave vga..." message.

In both cases, upon prompting the user with "unauthorized slave vga ..." the laptop will reboot itself every 30-60 secs(havent measured it but its about 30-60).

so in order to get nvidia card working, we need a bios modder who can whitelist the pcie under bios v2.07/2.04.

Or as I've read on some chinese website, if you flash v1.05, there is a good chance to get it working, since someone used that version to connect 755m ultrabay to a 750m laptop.

unfortunately, v1.05 is nowhere to be found

yep i already did.

tmw ill borrow an xfx 4850 from a friend. will see how it goes.

thanks for the info. i tried couple scenarios where i could boot using GT755m. and you're right. the laptop screen will come on just after the startup sound. (i did this by disabling the intel 4600hd and hotplugging the egpu after putting the laptop to sleep). however the laptop never recognized or detected the the egpu connected. i tried to use aida64 but that too didnt read the egpu.

Now my cards im testing with are old. and they might have compatibility issues(such as both of them are non-UEFI compatible).

i did. it didnt work.

3 hours ago, Andrew54 said:

Great work so far. I have same issue, black screen with 30second reboots.  Have flashed BIOS and EC 2.07.  Have uninstalled drivers.  Card is a GTX 780, using 8pin psu cable.

can you test it with amd gpu? so far nvidia gpus are resulting to 30 sec reboots.

well, if i let it sit, it doesn't seem to boot to windows at all, laptop keeps restarting about every 30 secs.

Do you get at least lenovo logo on your external display?

EC: 3.05

BIOS: 2.04

I also tried with 2.07 and got same results

i have tried to boot using another hdd with win10(legacy) and it gave me the same symptoms. so we can safely conclude that UEFI has nothing to do with it.

no both Gerald and ManyStrongWords

it must be the uefi then, ill try to install win10 on a spare hdd and see how it goes

What gpu are you using?

and your win10 is a UEFI?

i matched the bios and the settings, windows doesnt seem to boot at all with those gpus. and yes no startup sounds :/

It could be bcoz of those gpus are old and they use pcie 2.0 interface, or it has to do with UEFI(but i doubt it).

im gonna try couple more scenarios and let you guys know.

I have grabbed two old graphic cards from a friend (MSI GT430 4GB) and GT520 just for testing.

Getting a black screen on both of them. and laptop keeps rebooting every ~30secs

Tried with (BIOS 2.04 EC 3.05) and (2.07EC/BIOS).

the result is the same. Does it have anything to do with the fact i have Windows 10 UEFI? do I have to install it as legacy?

Thanks for the notice. I was going to order 480.

Congratulations man. I'm happy to hear it worked for ya. Enjoy. I will test it as soon as i get graphics card.

Let us know how it performs with the rx 480.

yes windows does load. i verified that with a music file opening at  windows startup.

the problem i couldnt find 2.04 anywhere on the internet.

can you try to disable your 750M in the device mgr and try to boot again using ur rx480?

--

yeah me too, i think it worked with 2.07. i have no way to confirm it since i dont have any graphics card now. but at least now it doesnt show that msg and boots to windows and well the screen is black.

here is a link of the bios v2.07 https://mega.nz/#!M04jhbqA!jrAhvWiEwSrtx6TlJ4HiZNOUXLi62mh0t1ZZsI-Q5A8

well, i think i know where the problem is. you dont have the latest bios, in fact you have EC 2.04 and bios 3.05. i have both ec and bios 3.08. Do you think think it is safe to downgrade?

if so, can anyone provide us with older bios files to downgrade. they are not available on lenovo's website.

update: I have just received mine. I dont have a graphics card yet but when i plugged it to the notebook it gave me the same error " unauthorised slave gpu....."