Lenovo Yoga 2 Pro - cannot turn on, keyboard blinking every 5 sec

[spintop]

Hi

My Lenovo Yoga 2 Pro cannot turn ON. The power Led light and keyboard flashes every 5 secs.
I search the website, found that its a common problem with this laptop.
Tried all the fixes but still it doesn't help. I removed the battery, cmos battery and hdd, power it on, still the same.
could be a mainboard issue??

Anyone can help ??

[spintop]

Re: Lenovo Yoga 2 Pro - cannot turn on, keyboard blinking every 5 sec

Anyone can help ??

[ciki]

Re: Lenovo Yoga 2 Pro - cannot turn on, keyboard blinking every 5 sec

Have few of them same issue ,replaced battery charging chip BQ735 i think ,but firs check bios if u can reprogram

[spintop]

Re: Lenovo Yoga 2 Pro - cannot turn on, keyboard blinking every 5 sec

Laptop can't boot at all so cannot reprogram.
Do I have to remove the bios chip and reprogram it outside ?
Thanks !

[spintop]

Re: Lenovo Yoga 2 Pro - cannot turn on, keyboard blinking every 5 sec

hi ciki

i managed to reprogram the winbond eprom with 8Mbytes bin file, by wiring the contacts out.
but the result is still the same, blinking keyboard backlight.

I also found an EC file, which chip do i need to program this to?

Thanks

[spintop]

Re: Lenovo Yoga 2 Pro - cannot turn on, keyboard blinking every 5 sec

does anyone has the dump file ?
thks

[RJARRRPCGP]

Re: Lenovo Yoga 2 Pro - cannot turn on, keyboard blinking every 5 sec

You said "cannot turn on", but I had an HP CQ 61 that had a keyboard light blink much like that.
I would get fan and drive power. Seemed it was reporting a CPU failure...
Same board manufacturer???

[spintop]

Re: Lenovo Yoga 2 Pro - cannot turn on, keyboard blinking every 5 sec

You said "cannot turn on", but I had an HP CQ 61 that had a keyboard light blink much like that.
I would get fan and drive power. Seemed it was reporting a CPU failure...
Same board manufacturer???

yes when plug in ac adapter, the keyboard backlight flashes every few secs, blank screen. i can feel the fan is also turning on and off.

maybe u are right it could be a cpu failure, i also cannot be sure.
i also cannot find the schematic, to measure the voltage rail

[RJARRRPCGP]

Re: Lenovo Yoga 2 Pro - cannot turn on, keyboard blinking every 5 sec

i can feel the fan is also turning on and off.

In my case, it would turn on and stay on, including the fan... Just nothing else would happen...

[spintop]

Re: Lenovo Yoga 2 Pro - cannot turn on, keyboard blinking every 5 sec

i noticed that when i just plugged in the ac adaptor (with battery removed), without doing anything on the on/off button, the keyboard backlight flashes on and off immediately.

maybe this is not normal, something is resetting itself.

[ciki]

Re: Lenovo Yoga 2 Pro - cannot turn on, keyboard blinking every 5 sec

i noticed that when i just plugged in the ac adaptor (with battery removed), without doing anything on the on/off button, the keyboard backlight flashes on and off immediately.

maybe this is not normal, something is resetting itself.

Try replace battery charging chip ,had 2 off them same symptoms

[spintop]

Re: Lenovo Yoga 2 Pro - cannot turn on, keyboard blinking every 5 sec

Try replace battery charging chip ,had 2 off them same symptoms

i cannot find the chip u mentioned on the board. can u point to me location of this charging chip in image.
thanks

[tlh]

Re: Lenovo Yoga 2 Pro - cannot turn on, keyboard blinking every 5 sec

bios i have the same problem.
Is there a bios to send

[spintop]

Re: Lenovo Yoga 2 Pro - cannot turn on, keyboard blinking every 5 sec

mine laptop is still not possible to fix yet.