Having a hard time dumping BIOS - Lenovo Ideapad Duet 3 (11IAN8)

[anton brunner]

Hello everyone,

I'm having a hard time dumping the BIOS of a Lenovo Ideapad Duet 3 (11IAN8). The chip is a Winbond W25R256JVEN, directly soldered to the board in a WSON8 package.

Since there are lots of tiny components near the chip, I was hesitant to desolder it using hot air. Instead, I soldered thin wires directly to the chip's pads and connected them to a CH341A programmer (photos attached).

The chip is detected correctly in both NeoProgrammer and ASProgrammer, but I'm unable to get a consistent dump. I've tried over 15 times — shortened the wires to under 10 cm — but the resulting dumps always have different MD5 checksums. I also performed the 3.3 V mod on the CH341A beforehand (following the common guide) to ensure safe voltage levels.

So, my question is:
Do I absolutely need to desolder the chip, or is there anything else I can try to improve the signal integrity and get a reliable dump?

Any advice is greatly appreciated.
Thanks in advance!

[anton brunner]

Anyone? 🥲

[mcplslg123]

CH341A programmer is not at all reliable. It often read/write a chip without error but the data written/read is not correct. I dont trust it at all specially for chip which are bigger in size like 16mb/32mb.

I'll recommend to buy a RT809F which is cheap yet very very reliable.

[m1ch43lzm]

I suggest to desolder the chip and place it on a WSON8 to DIP8 adapter board, as there may be other components also powered from +3.3v on the board



Or this one, you don't need to solder the chip to it


Or if you already have a SOP8 adapter, you can cover with UV solder mask the exposed traces on the inside, like this, as the WSON8 package has an exposed ground pad



Then try again, the CH341A is really slow when reading chips >8MB taking several minutes, best practice is to read the chip 2-3 times and you compare the files with a hex editor, they have to be exactly the same
There's also a newer version called CH347 (purple PCB), i haven't tried it, only the CH341 with a green rectangular PCB (the one that doesn't have the wrong voltage on the data lines)

If you're looking for a programmer I use Xgecu T48 programmer

[DeXXter]

Desolder it
Also get copper tape to protect plastics and other components, this is way better than kapton and aluminum tape.

[Aliencomputres]

Desolder it
Also get copper tape to protect plastics and other components, this is way better than kapton and aluminum tape.

copper is a good conductor of heat,so it has no place in the hot air soldering/desoldering process.

[anton brunner]

Thank you all for the great advice!

Since I'm working with a very limited budget, I'll go ahead and try desoldering the chip and attempt another read using the CH341A. I've also ordered some copper tape to protect the surrounding components during the process.

If that still doesn't yield a clean dump, I'll consider investing in a more reliable programmer.

Thanks again for your support!

[rumpumpel1]

this is how I do it

[anton brunner]

copper is a good conductor of heat,so it has no place in the hot air soldering/desoldering process.

That makes sense. The problem I'm having is that the Kapton tape I have doesn't stick very well when it gets hot, and then hot air starts to lift it at the edges.

Would it make sense to first cover the components with Kapton tape, and then use copper tape around the edges to seal it down and prevent airflow from getting underneath?

[rumpumpel1]

I also recommend buying a more expensive programmer that has a chip that improves the signal quality. It makes the reading much more reliable.

[m1ch43lzm]

That makes sense. The problem I'm having is that the Kapton tape I have doesn't stick very well when it gets hot, and then hot air starts to lift it at the edges

Same thing happens to me, the "krapton" tape i have sometimes doesn't stick at all to the board, but sticks very well to itself
Unless you got the real kapton made by DuPont

You need to worry about the plastic connectors nearby as they will get melted, and the CPU, you don't want to heat it too much (also notice the black glue/epoxy/whatever that Lenovo likes to use on the corners of the CPU/RAM/GPU)

I saw a video of someone using PTFE high heat adhesive tape, like the one used for heat sealing plastic bags




Another idea is to make shields out of soda/beer/(insert favourite drink) cans, not 100% sure what he used, maybe copper sheet bent to shape

[DeXXter]

copper is a good conductor of heat,so it has no place in the hot air soldering/desoldering process.

The copper acts as shield for the hot air, most of the plastics used on motherboards can handle high temperatures, but not the direct air. Besides it's no like you will put the nozzle directly on the covered plastic right?

[Aliencomputres]

The copper acts as shield for the hot air, most of the plastics used on motherboards can handle high temperatures, but not the direct air. Besides it's no like you will put the nozzle directly on the covered plastic right?

copper is a good conductor of heat,so it has no place in the hot air soldering/desoldering process.

Use Kapton tape or aluminium tape as thermal shield.

[DeXXter]

copper is a good conductor of heat,so it has no place in the hot air soldering/desoldering process.

Use Kapton tape or aluminium tape as thermal shield.

Yeah you clearly haven't tested that, I've replaced all kind of mosfets, ecs, some pch (crap around connectors) and haven't got a single plastic melted around on the board while using copper tape, even use it to protect electrolytic capacitors on gpus. For me it works better than aluminum, kapton and even PTFE (tested all of those).