Mixed up BIOS chips. Which one is which?

[afaruky]

Dear disc whisperers,

I have a WD10JMVW-11AJGS1 with a corroded PCB (2060-771961-001 rev A). I'd had a technician swapped the BIOS chips to donor PCB but couldn't saved the disk. I recently realized that U12 and U14 chips have different marking. Actually one is marked clearly as Winbond 25X20CLVIG but the other is unmarked. I also have two chips lying in the same box with similar pattern.
I assume there was a mix up during swap and I read the dumps with CH341A. I searched through one the file and at 0003F080 line, I found my HDD model. Unfortunately I cannot tell if this one is U12 or U14.
Is there any chance that you can check at which position this chip needs to be soldered?

Also, the donor PCB I used is rev B. Seller claims rev A and B are interchangeable but I'm not certain about that.

Thanks.

[northwind]

I searched through one the file and at 0003F080 line, I found my HDD model. Unfortunately I cannot tell if this one is U12 or U14.
Is there any chance that you can check at which position this chip needs to be soldered?

That's the 'ROM' and needs to be at U12.