Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

[piernov]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

IMVP_VR_CPU_OK should be good. It would be bad if it was pulled down to 0V. (PGOOD is most likely an open-drain output from the buck controller)

[KvnTM]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

Measured:
IMVP_VR_CPU_OK: 1.06V steady
CPU_CORE: 1.71V steady

IMVP_VR_CPU_OK: 1.06V steady

Theres your problem my friend. The vcore pmic doesn't report "Power OK" to the CPU.
IMVP_VR_CPU_OK is connected to +1.05V_VCCST by a 10k pullup resistor (R117). That is what you are measuring.

It is supposed to go high (3.3v). I can't find a Datasheet for ISL95817HRZ but the PGOOD output is usually supposed to go high on ISL CPU PMIC's as soon as the controller is in a stable state.

Either your ISL95817HRZ is bad or the current sensing circuitry is damaged.
Please measure and confirm following resistances:

PR9203 & PR9254 = 1Ohm
PR570 & PR574 = 10kOhm
PR15 & PR21 = 3.65kOhm

Also please measure voltage of H_VR_ENABLE. Pin 29 on ISL chip or on PR9139.

Remember that measuring resistances in circuit will change the result. But it should be close.

[GIFixed]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

CPU_CORE seems a bit high for an ULV Processor. They usually run below 1 volt. Usually somewhere between 0.6 - 0.8v. Someone correct me if I'm wrong. Is CPU_CORE steady?

Jumping between 300mA and 500mA means it is still power cycling.

Please measure voltage of IMVP_VR_CPU_OK. Pin 22 on vcore pmic ISL95817HRZ.

Measured:
IMVP_VR_CPU_OK: 1.06V steady
CPU_CORE: 1.71V steady

[KvnTM]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

1.7-1.8V on CPU VCore is ok for Haswell/Broadwell. Others (from Sandy Bridge) will typically boot at 1.1V then drop at 0.9V or a bit lower.

OK thanks for the correction! Is this also true for ULV Processors? I can remember my yoga (i5-4200U also Haswell) runs at 0.6 - 0.85V. Might be different upon boot for sure.

[piernov]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

1.7-1.8V on CPU VCore is ok for Haswell/Broadwell. Others (from Sandy Bridge) will typically boot at 1.1V then drop at 0.9V or a bit lower.

[KvnTM]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

Now measured all power rails:

I have disconnect the bord from battery and ALL other things.

Using only Lenovo charger:

+3VALW : 3.3V
+5VAUX: 4.94V
+3VAUX: 3.3V
+1.2VSUS: 1.35V
+0.6V: 0.68V
CPU_CORE: 1.7V
5V_Walkport: 5.09V
+1.5V: 1.5V
+1.05VAUX: 1.07V

MAINON: 3.3V


Using lab power supply giving it 20V at power connector, and measured current:

OFF state: 0.005 A
ON state: 0.500-0.560 A fluactuating and then every 4 seconds stablizes at 0.300 A for a short time and then fluactuate.



The CPU and RAM chips get warm. The fans spins according to the temperature.

CPU_CORE seems a bit high for an ULV Processor. They usually run below 1 volt. Usually somewhere between 0.6 - 0.8v. Someone correct me if I'm wrong. Is CPU_CORE steady?

Jumping between 300mA and 500mA means it is still power cycling.

Please measure voltage of IMVP_VR_CPU_OK. Pin 22 on vcore pmic ISL95817HRZ.

[GIFixed]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

Tried to attach a bootable USB stick with activity LED. There is power but no sign of activity.

[GIFixed]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

Now measured all power rails:

I have disconnect the bord from battery and ALL other things.

Using only Lenovo charger:

+3VALW : 3.3V
+5VAUX: 4.94V
+3VAUX: 3.3V
+1.2VSUS: 1.35V
+0.6V: 0.68V
CPU_CORE: 1.7V
5V_Walkport: 5.09V
+1.5V: 1.5V
+1.05VAUX: 1.07V

MAINON: 3.3V


Using lab power supply giving it 20V at power connector, and measured current:

OFF state: 0.005 A
ON state: 0.500-0.560 A fluactuating and then every 4 seconds stablizes at 0.300 A for a short time and then fluactuate.



The CPU and RAM chips get warm. The fans spins according to the temperature.

[KvnTM]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

You could get one of these LPC Debuggers as a last resort:
Link to eBay

This would show if there is any activity on the bus. But I think you're able to fix this without one of these. It probably is something stupid like always

[KvnTM]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

Hi KvnTM,
Thank you for helping me.

I have now flashed your suggested bios bin
(https://www.badcaps.net/forum/showpo...9&postcount=25).

Status:

Now it kinda power up constant: no power cycling.

Fans spins. Power rails are steady(did not checked them all).

USB power is steady.

Keyboard light is OK.
Pressing power button for 5 seconds turns off -> works nomally.

But:
Black screen.
No beeps.
No sign of booting.

What is next step?

Don't expect the laptop to give you any beeps. Only a very few laptops will give the user feedback of a hardware failure.

My best bet would be a ram issue. Since it is powering up and all power lines are present. Does the CPU warm up? Does the board show any sign of liquid damage?
Have you tried plugging in a USB Stick to see if there is any activity? Most USB Sticks will have an activity led.

Please re-measure all power lines and post them here. Maybe there is something you didn't catch the first time. Also measure the current drawn by the board. Disconnect the battery while measuring. You only want to measure the current of the board and not the battery charging current.

BTW I'm not sure about the LPC override thing. Pretty sure you could emulate the bios chip in some way since it is just a normal SPI bus. There are LPC analyzers which will give you the POST code and possibly where it is stuck but they won't be of any help because you don't know what they mean.

[GIFixed]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

Alright. Let me know if it worked.

Hi KvnTM,
Thank you for helping me.

I have now flashed your suggested bios bin
(https://www.badcaps.net/forum/showpo...9&postcount=25).

Status:

Now it kinda power up constant: no power cycling.

Fans spins. Power rails are steady(did not checked them all).

USB power is steady.

Keyboard light is OK.
Pressing power button for 5 seconds turns off -> works nomally.

But:
Black screen.
No beeps.
No sign of booting.

What is next step?

[GIFixed]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

By the way, is it possible to boot the yoga 2 pro from LPC port overriding the onboard bios chip?

Like these Matt card does on macbooks:

http://www.cmizapper.com/products/mattcard.html

[KvnTM]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

Thanks. I will try on monday.

Alright. Let me know if it worked.

[GIFixed]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

You already got one step further which is good. It means the EC is most likely fine since it controls leds, keyboard, etc. My Yoga 2 (Not Pro) did the same thing after a flashing a wrong bios. Just try to find a different bios and compare them by size. They must match the exact size of the rom chip.

EDIT: Give the one in my attachments a try.

Thanks. I will try on monday.

[KvnTM]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

It now powers up (only keybaord backlight and power LED) for 3 seconds, then turn off for about 5-8 seconds.

Nothing shows up at screen. Neither screen backlight.

Before flashing BIOS the CPU still remains cold.

After flashing BIOS: the CPU gets warm not hot. But no fan spin at all.

Attached the "original" dumped BIOS flash.

You already got one step further which is good. It means the EC is most likely fine since it controls leds, keyboard, etc. My Yoga 2 (Not Pro) did the same thing after flashing a wrong bios. Just try to find a different bios and compare them by size. They must match the exact size of the rom chip.

Fan spin is NOT an indicator for a working board on these laptops.
The fan will spin up when the cpu gets hot.

EDIT: Give the one in my attachments a try.
The one I attached is a newer Version 76CN35WW
Your Dump is 76CN27WW

[GIFixed]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

Just to clarify.. It is still power cycling every 3 seconds ?
"It now power cycling and now power on for 3 seconds." Doesn't really make sense to me. Is it NOT power cycling anymore? Or does it still cycle every 3 seconds?

Dont worry about modifying the bios rom yet. It will work even without doing anything to it. POST will just be much much slower.

Could you attach the original bios dump from your board?

It now powers up (only keybaord backlight and power LED) for 3 seconds, then turn off for about 5-8 seconds.

Nothing shows up at screen. Neither screen backlight.

Before flashing BIOS the CPU still remains cold.

After flashing BIOS: the CPU gets warm not hot. But no fan spin at all.


Attached the "original" dumped BIOS flash.

[KvnTM]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

Now I got the programmer.

To see if there is difference, I took backup of BIOS, then flashed the one fron BIOS request thread. Yoga 2 pro.

It now power cycling and now power on for 3 seconds. It is a good sign.

Nothing on screen.

There is someting I should do with the BIOS file before flashing, but what and how to do it for this machine?

Just to clarify.. It is still power cycling every 3 seconds ?
"It now power cycling and now power on for 3 seconds." Doesn't really make sense to me. Is it NOT power cycling anymore? Or does it still cycle every 3 seconds?

Dont worry about modifying the bios rom yet. It will work even without doing anything to it. POST will just be much much slower.

Could you attach the original bios dump from your board?

[GIFixed]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

Now I got the programmer.

To see if there is difference, I took backup of BIOS, then flashed the one fron BIOS request thread. Yoga 2 pro.

It now power cycling and now power on for 3 seconds. It is a good sign.

Nothing on screen.

There is someting I should do with the BIOS file before flashing, but what and how to do it for this machine?

[KvnTM]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

Unfortunately, we dont have an oscilloscope. But I personally have this logic analyzer, but never used it:

https://www.ebay.com/itm/USB-SALEAE-...a9987303219201

Is it usable?

Unfortunately, the sampling rate is way too slow.

This is what the datasheet from a typical Flash Chip (W25Q64) says:
– 104MHz Single, Dual/Quad SPI clocks
– 208/416MHz equivalent Dual/Quad SPI

You need at least a few hundred MHz of bandwidth to analyze it correctly.
You are better off investing in a proper scope rather than a logic analyzer. Logic Analyzers with that bandwidth are reaaallly expensive. Probably the same as a proper scope.

But you can give it a try. Maybe you can see some activity.

[GIFixed]

Re: Lenovo Yoga 2 Pro 20266 Stuck in sleep mode

Unfortunately, we dont have an oscilloscope. But I personally have this logic analyzer, but never used it:

https://www.ebay.com/itm/USB-SALEAE-...a9987303219201

Is it usable?