Lenovo V155 15-API no display

[AppleLover123]

Hello guys,

i have this laptop here that wont display.
First thing i did was checking voltages and all are Present.

After that i tried another ram sticks but they didnt change anything as well.
Then i tried programming the bios with two different bios files but nothing changed (i used the ch341a without the 1.8v Adapter but I was able to read/write the chip).

Now i thought it could be a ram issue.
I flashed a bios with onboard ram disabled (dump attached) and i moved the resistors on the right Place like it's Show in the picture (attached).
But nothing changed.
The last thing i did is desoldering the ram Chips from the motherboard but the only thing changed is the current draw that went from 800-900milliamps to 370milliamps.

What could be the fault here?
Does it has anything to do with the bios chip? (W25Q64FW 1.8V)

I have attached a Bios from Lenovos Website that was given to me in a Bios Request...Can someone disable the onboard ram in that bios for me?

[SMDFlea]

All laptop bios requests go here -> https://www.badcaps.net/forum/troubl...-requests-only

[mcplslg123]

You took steps in haste. The current draw indicates the mb is not recognising the external ram and still looking for onboard ram.

There was no need to de solder onboard ram unless shorted.

[AppleLover123]

You took steps in haste. The current draw indicates the mb is not recognising the external ram.

But what did i do wrong?!
I moved the resistors on place, diabled it in bios via ram patcher and desoldered the ram (thought it wouldnt recognize it anymore).
Do i have to move another resistor?

[AppleLover123]

SMDFlea does the ram patcher also removes the entrys for the dimm slot in some cases?

[SMDFlea]

SMDFlea does the ram patcher also removes the entrys for the dimm slot in some cases?

The ram patcher removes SPD entries in the bios. The ram that you put in the dimm slot has it`s own SPD on a small chip.

[mcplslg123]

But what did i do wrong?!
I moved the resistors on place, diabled it in bios via ram patcher and desoldered the ram (thought it wouldnt recognize it anymore).
Do i have to move another resistor?

Desoldering the ram-this step was un necessary.

[SMDFlea]

But what did i do wrong?!
I moved the resistors on place, diabled it in bios via ram patcher and desoldered the ram (thought it wouldnt recognize it anymore).
Do i have to move another resistor?

Do you have a RAM slot tester or an Oscilloscope ?

[AppleLover123]

Do you have a RAM slot tester or an Oscilloscope ?

No, i don't have a ram slot tester but I can use a Oscilloscope from a friend.
Never did those measurements tough but I think i came to the conclusion that this Laptop may has a corrupt ec Firmware because of the fact that when the bios Chip is removed and i plug the charger it does exactly the same as with the bios chip and it doesn't read the power button.

I Ordered the Svod 4 with the zif sockets and it will arrive in about one week...

[AppleLover123]

I programmed and replaced the ec chip with another one but the exact same Thing happens.
It still wont react to the Power Button and it keeps trying to start and goes after Plug ging ac to 921 milliamps (current still changung) than to 910 freezes and goes down to 861 mamps and stays there. It only goes up when the Fan is spinning.

Now this thing is quite a challenge because i never did those measurements but should i list an Signal of the ec Chip or pwm Chip? And when yes which Signals? Do i need an oscilloscop?


<--------------->

Like i said all voltages are present. The only thing that i found weird is that the two input mosfets of the 1.2v Power supply are getting slightly warmer than the other mosfets like on the 0.9v one.

Also when i had the Laptop at first it did react to the Power button just after i flashed the bios it didnt anymore including the original bios.