What's the easiest way to read/write to my laptops bios chip?

[Hentrox]

Hello, 

I have a Samsung NP270E5E-X02AU laptop. I'd like to unlock the advanced/hidden options in the bios. Is there a way to read/write to the bios chip so I can do this?

The bios chip on the motherboard reads "winbond 25Q64CVSIG1328". I've tried using a CH341A programmer, however, have had no success. I've read on this thread (https://www.eevblog.com/forum/repair/ch341a-serial-memory-programmer-power-supply-fix/50/) that because it outputs 5V it's not compatible with my motherboards bios chip (supposedly runs on 3V), and that there are mods you can do to the CH341A to remedy this.

I did one mod detailed by RaceJay on page 3 (reply #62), and it still did not work. I don't have the capacity to do more modding/soldering stuff.

Is there a method to achieve what I want without having to do modding/soldering etc? If it requires purchasing another tool, I'd consider it, depending on the price.

Thanks!

[wraper]

Without desoldering the chip it won't work.

[Hentrox]

The CH341A came with a lead/clip that clipped onto the bios chip. Why is desoldering necessary if devices with leads/clips exist?

Edit: I assume you're talking about the bios chip when you reference the "chip"?

[wraper]

Because flash IC is connected to the circuit that will interfere with programming.

[Hentrox]

So, do only some laptops have "flash IC" that is "connected to the circuit board"?

Because I used the CH341A with the lead/clip to flash a bios to a Acer laptop a while back.

[amyk]

Assuming the laptop itself is functional, boot to a suitable OS and read it from there. Writing is not without risk but doable.

If the laptop is not functional, then you'll need a standalone programmer. I've seen chip-clips work well but it could be a matter of the voltage and being able to supply enough current that the IC works --- since it will try to power the rest of the laptop too.

[wraper]

Because I used the CH341A with the lead/clip to flash a bios to a Acer laptop a while back.

You were lucky that particular circuit did not interfere too much, but overall it rarely works. Also there is a high risk of frying the motherboard.

[Hentrox]

SOLUTION FOUND - Pressing "CTRL + ALT + SHIFT + F4" while in BIOS unlocked advanced options.

[Whales]

My CH431A has a jumper for choosing between 5V and 3.3V.  I successfully used it yesterday for reading & flashing a BIOS.  The fiddly bit was the cheap clip (cleaning the clip and the chip seemed to help greatly).

[wraper]

My CH431A has a jumper for choosing between 5V and 3.3V.  I successfully used it yesterday for reading & flashing a BIOS.  The fiddly bit was the cheap clip (cleaning the clip and the chip seemed to help greatly).

That's about an issue in older CH341A. When selecting 3.3V, they still pushed 5V on data lines, mine was like that. Someone on this forum said that programmer he bought more recently no longer had this issue.

[Whales]

I just probed my CH341's pins with my multimeter and indeed yes it's sending 5V on some of them    That jumper is a lie, I'll get on fixing that.

> Assuming the laptop itself is functional, boot to a suitable OS and read it from there. Writing is not without risk but doable.

Not recommended.  Flashrom doesn't support all "internal" programmers and even when it does it's common for certain regions to be blanked out ("security").  Using your own external chip programmer is much more reliable.

> You were lucky that particular circuit did not interfere too much, but overall it rarely works. Also there is a high risk of frying the motherboard.

I'd never survive desoldering and resoldering, one project I did required me to write to the chip dozens of times.  The chip clip was perfect for that and caused me no dramas (even with its nasty 5V).

On another more recent laptop I found that disconnecting the main battery made the reads and writes reliable.  Prior to that I was getting a different image every time I tried to read (presumably due to something else trying to talk to the flash chip).