IBM ROM

[Bruno]

Hi all

I have a defect 040AVVA. made in Hungary.
The PCP looks like AVVN.
Is there any AVVY with ROM-Chips in the world?
On a funcional PCB i have 3.3V at the pin near "U7".
At the Patient PCB there is 0V.

My question are, can i swap the ROM by soldering?
In Savemode the PCB is not functional.

Very Thanks
Bruno

[Yuriy Manjilevskiy]

Hello Bruno,

PCB's AVVA and AVVN are usually the same.

Yes, its necessary to resolder ROM and NV-RAM for PCB swap.
If its Mask ROM, which is inside of microprocessor, necessary to find ROM by NV-RAM version and swap PCB with the same ROM version.

[Bruno]

Thank you Yuriy

Yesterday i have resolder the NVRAM only and solder to the Donor PCB.
The Drive becom ready. After SA structure checking i could read recover all Data.

best regards
Bruno