[SOLVED] Laptop stuck in boot loop

ToxicCow19

Reputable
Aug 18, 2016
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4,510
Hi, about a week ago I made a double boot Hackintosh with my Lenovo Y700. I have two drives, one being my main Windows install and the other my macOS install.

Last night I was using Windows but needed to do something on macOS, so I turned off my laptop, turned it back on and changed the BIOS settings that macOS needs to boot (Intel Vitual Technology disabled, secure boot disabled, fast boot disabled, Intel Platform Trust disabled, changed from switchable graphics to internal graphics, and changed drive order to boot on macOS disk. It’s worth mentioning I’ve done this without ill consequences in the past). I saved and exited BIOS settings, my laptop turned off after that as usual, and then it seemed to turn back on.

After that, it’s been stuck in a loop. When I press the power button, I get keyboard backlight and fan spin for around 1 second before it turns off again. Then it goes on to try and turn on again and then it shuts off. It gets stuck in this loop until I disconnect the battery. I can’t even get to my BIOS settings because the loop happens so fast.

I read on some other forum that it may be an error while POSTing.

So far I’ve tried:

  • Resetting the CMOS (disconnected main and CMOS battery for 2+ hours)
  • Reseating RAM
  • Changing RAM stick to the other slot
  • Disconnecting both my SSD and HDD
  • Plugging in power cord when trying to boot

I don’t know what else to do. I’ve tried all of the above at least twice and I can’t really get any support with the coronavirus crisis. Please help, I already posted this everywhere on the internet and nobody gives me a solution. Thank you

Here are my specs:

Laptop model: Lenovo Y700-15ISK 80NW
CPU: Intel Core i5-6300HQ
GPU: GeFore GTX 960M 4GB
RAM: 1x8GB 2133 MHz DDR4
HDD: Some 1TB WD Blue (Win 10, main)
SSD: Gigabyte 256GB NVMe PCIe (macOS)
 
Solution
Actually nevermind found the actual cause here : http://tech.memoryimprintstudio.com/replace-bios-chip-in-lenovo-y700-motherboard/
It is indeed bios corruption.

You can try the method i just told you in last post with usb it might work (Probably corrupted intel me region)
This most likely wont work but its worth a try.

2nd method is to buy ch341a programmer with soic clip and rewrite the fixed bios file to the right winbond chip as seen on this "replace bios chip" post, you might be able to do it without removing the chip with a soic clip.
If i where you i would order the programmer its very cheap.

Everything you need here ...
Have you tried running it without internal battery and only power cable?
I dont think your gtx is dying since you havent stressed it and used only integrated, might be corrupt bios or somethign shorted on the motherboard, it is not EC startup chip cause your getting fan spin.

You can try isolating the problem by removing components and testing power on in between, this means first remove power cable and internal battery (atleast the connector)

Then start removing parts like wifi card, usb hub connectors and speakers , LCD panel cable, ssd / hdd, etc.
You can remove everything you can without removing the motherboard, also remove power button / keybord and cmos battery connector. You can plugin external monitor to HDMI port. Double check nothing is shorting on the motherboard or connectors not touching motherboard, then plugin power cable and see if you get longer fan spin (you will boot straight without power button since cmos battery is removed) , if you dont then plug off power cable again and add power button cable and try booting it with power button.
You can try without fan too if its shorted and causing it to boot loop (not for too long this might overheat just quick test if you get pic on external monitor)

This way you isolate anything but the motherboard itself, if you get working just put it back together component by component and see when it fails (the component which is causing it)

If its not this probably bios corruption or security chip problem.
 
Actually nevermind found the actual cause here : http://tech.memoryimprintstudio.com/replace-bios-chip-in-lenovo-y700-motherboard/
It is indeed bios corruption.

You can try the method i just told you in last post with usb it might work (Probably corrupted intel me region)
This most likely wont work but its worth a try.

2nd method is to buy ch341a programmer with soic clip and rewrite the fixed bios file to the right winbond chip as seen on this "replace bios chip" post, you might be able to do it without removing the chip with a soic clip.
If i where you i would order the programmer its very cheap.

Everything you need here : https://www.ebay.com/itm/SOIC8-SOP8-Test-Clip-CH341A-Flash-BIOS-USB-Programmer-fur-EEPROM-25CXX-24CXX/114031747365?

3rd method is to desolder the chip and use the programmer to rewrite bios chip / replace the bios chip if it has gone bad (unlikely)
 
Solution