HTS547575A9E384 IBM-ARM Corrupt NV-RAM

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This drive came to me with PCB failure (burnt components). NV-RAM at first appeared to be okay as I can read ID, mu-code, Heads, Head Map and SN. However when installed on the drive it will not spin (also changed heads in case of preamp issues).

Patient drive will spin with different NV-RAM, Patient PCB will spin up a donor drive. But Patient NV-RAM on Patient drive (donor board, new heads) will not spin.

Looking at the patient NV-RAM and comparing it to another NV-RAM it looks almost identical. ie there are no glaring differences where corruption could have occurred.

Any ideas?


New member
Initially I physically swapped the NV-RAM as the original board was damaged. Took a copy of the NV-RAM after installation. Now have tried a couple of donor board by transferring the data through software. Same result.
Have you solved this case?
If not, send me NVRAM to me so that i can check hex code inside. If i see corruption, i will fix it and send to you the adjusted nvram file.
Sorry, i said NV-RAM but i wanted to say ROM dump.
Please, dump patient rom, if possible do it with eprom reader. Inside ROM should be two copies of nvram, those two copies should be identical if you compare them with a hex editor.
If i find differences by comparing them, then definitely would mean that nvram is corrupt, in that case i can try to fix it manually for you.


New member
The strange thing about this ROM is that PC3000 read it as 512kb, but most ROM's for this family are 256kb. I have attached (and have tried both sizes) on the drive but it still will not spin.

Many thanks for your help.


  • ROM.7z
    107.8 KB · Views: 171
As i know, PC3000 has a bug that does only 50% ROM backup from Hitachi ARM drives, also MRT has this same bug.
I don't know if acelab corrected this bug in last update, maybe yes and this would give a sense on why now you get full rom dump if you recently updated it.

I compared both NVRAM copies in your rom, they are identical, so i don't think nvram is corrupted. My opinion is 'corrupted ROM code'.
I would try to write entire 512 Kb patient rom on donor PCB with external programmer, let me know if this solves the problem.

You uploaded two ROMs, 256 ROM.bin and ROM.bin files, first file is different than first half of second file.
ROM comparing.jpg