Lenovo Ideapad 5 15ARE05 random freeze

[Corentinrhr]

Hello, I have exactly the same problem with the same laptop model. Does the reflow of your CPU still work to this day? How did you do it?

[mcplslg123]

Re: Lenovo Ideapad 5 15ARE05 random freeze

Reflow of the SOC wont work beyond a couple of days. You need to reball it.

[EsIstSimon]

Re: Lenovo Ideapad 5 15ARE05 random freeze

Since i got no response here, i just went for my best guess and did a reflow of the cpu.
Machine works like a charm (at least for now) =)

Maybe this information will help someone in the future.

Cheers

[EsIstSimon]

Hi there,

i have a Lenovo Ideapad 5 15ARE05 that will freeze randomly.
Sometimes it wont even post, sometimes i can use it for a couple seconds or minutes before it completely freezes.
Sometimes the screen freezes, but still displays the last frame, sometimes (pretty rare) the screen goes black

It does not matter what i do. Installing windows, starting Fedora or just sitting in the bios. After some time it will freeze.
When the freeze occurs, the laptop draws a pretty constant wattage (it will just stay on the value that it draws, when it locks up +- couple hundred mw) and will never return to a functional state.
It does not seem to matter if its a cold boot or if it power cycled a few times.
When it posts (screen comes on and Lenovo Logo appears) and i shut it down right away, it works for the next boots without an issue.
When it has frozen once, it takes some time and/or trys to get it back to a working state.

In this no post state, starting the laptop will turn on the keyboard backlight and fan for 2-3 seconds, both then turn off and the laptop draws ~14watts.
I can still turn on/off the keyboard backlight, but Capslock / Fn lock wont work. The cpu will heat up and the fan will come on from time to time.

What i have tried so far:
- Remove battery and CMOS and perform a static discharge
- Remove everything connected to the board
- Reflash Bios. I extracted it from Lenovo updater and trimmed the file according to the original backed up bios. I flashed it with a CH341A, while the BIOS chip was still on the board. I read in one or two threads that people recommend flashing the bios out of circuit, do you think i should give this a try?
Also i have not transfered the DMI to the new BIOS yet, as i wanted to test it first, but this should not be the problem here, right?

The board is completely clean and since it will work from time to time, i dont think anything has blown.
My best guess would be a failing APU, but since i am pretty new to the world of electronics repair, i kind of lack the experience to be sure about that.
I was thinking about a mild reflow of the cpu, but i am not sure it this will result in anything, since it does not matter if the cpu is cold or not.
Another guess would be a failing memory chip.

Maybe you guys have another idea and can nudge me in the right direction

Thanks a lot!