LSI MUSE-B2B2-L hard drive controller (Hitachi Deskstar SATA drive failed)

[Unixon]

Does anybody have datasheet for this SoC ?

[fzabkar]

I doubt very much that you will find any data on HDD MCUs, even for those from the 1990s. If you have a repair question, perhaps I could help.

[Unixon]

Hitachi Deskstar HDS722020ALA330 2Tb mfg 09/2009 stopped responding on SATA without any obvious reason (other than working 24/7 for years without any issues). SATA controller on motherboard couldn't see the disk anymore but it was trying to do something and it took noticeable time during start up. The disk has been switched off for a week or so, then I plugged it into a dock station where it spun up and initialized but it was unreadable, reported some SATA errors and then has been stopped on controller command. After that I didn't hear a thing from this disk, no SATA errors, no spin-up. I hoped there's a debug UART or something to talk to MCU and at least get some information on what's going on.

[fzabkar]

I'm not aware of a UART port on Hitachi HDD PCBs.

The symptoms you describe are consistent with an internal fault, probably bad heads or media. When the drive starts up, it unpacks the PCB ROM code into RAM and transfers control to it. This RAM code then fetches more code overlays (discware) from the reserved System Area (SA) on the platters. The SA stores things like the LBA-to-CHS translator, defect lists and SMART. If the SA becomes inaccessible, or if one or more of the critical firmware modules cannot be read, then the drive remains busy or spins down.

HDD - computer within computer:
http://www.hddoracle.com/viewtopic.php?p=19087#p19087

A no-spin condition usually points to a PCB fault, although a bad preamp on the headstack can also cause the MCU to decline spin-up.

If you want to troubleshoot the PCB, please provide a detailed photo and I'll identify some test points for you.