I think I know what the problem is, but I'm hoping someone can verify or (even better) prove me wrong.

I have a seagate ST3750640A which needed a head replacement. Donor drives are $200...ridiculous when the ST3750640AS can be had for less than $30 (which I bought).

Practically everything matches on this xxAS drive, except of course it is SATA instead of PATA (P/N is 9BJ148-305 vs 9BJ048-305, firmware is 3.AAE for both, site code is WU for both).

I swapped out the heads, plugged it up, and I hear one clunk after spin up. Terminal says:


HM
SFI
!


F>R
F> Code - FF Track 162A1.0.046 Sns 046

F>j
F>ERR App Code incompatible SFL code


What someone said on another forum was that it has to do with my preamp not matching what the drive expected...so my conclusion is that my donor drive isn't actually suitable (somewhere on this forum I did find someone claiming the heads should be swappable).

I even tried swapping the original PATA PCB with the SATA PCB from the donor drive. I haven't found wires I can connect to the SATA jumper and read terminal output yet, but everything sounds the same (spin up, one clunk, then not much of anything other than motor spinning).

Does anyone have any ideas other than to find a closer match for the donor? Additionally, ; yields:

Age=00 Type=00 MxCyl=0001572A MxHd=00 MxSct=280 BSz=010M TCode=00000000

so it doesn't appear to be detecting the heads.

Thanks so much in advance!!

I would think that "ERR App Code incompatible SFL code" means that there is an incompatibility between the ROM code and SA code, or that the App Code cannot be read.

If the drive were detecting the wrong preamp, then why would it bother to spin up? Can you see the part numbers on the donor and patient preamps?

_________________
A backup a day keeps DR away.

Thank you so much for the quick reply.



It appears that my preamp is completely covered in gold. Here is a photo I just took of my bad heads that I removed.



How can I tell what IC is under there?




I reread the forum posts here
viewtopic.php?f=1&t=22544&hilit=ERR+App+Code+incompatible+SFL+code

and then I looked up what my return code for my R command (FF) meant:
Unsupported code in the new preamp interface

which then led to

viewtopic.php?t=11483&start=

which again seems to confirm that the preamp is incorrect.


So....any chance of getting this head stack to work with this drive? OR do I just need to find another donor? If it is an incompatibility between the SA and preamp, is there any possibility of copying part of the SA from my donor drive and using that?


Thanks!

An FFh error code means "Unsupported code in the new preamp interface". I don't know if this relates to the "Code - FF" in your first post, though.

I suppose that the "ERR App Code incompatible SFL code" response to a "j" (jump to app code) command would be understandable if there were no app code loaded in RAM.

FWIW, I notice that Level 2 has an "Hx" command (Select Head) where "x" is "Physical Head to Select".

You might like to see how the original headstack responds to this command, and then compare it against the new preamp. AISI, you could just attach the PCB to the HDA connector without reinstalling the headstack.

There is also an "Sx,y,z" (Seek Cyl/Head) command.

As for identifying the preamp, I can't see any way to do this just by visual inspection. However, I'm surprised that there isn't a tool on the market that can read the preamp's ID and registers via its serial interface. If I were in the business, that's something I'd endeavour to build for myself.

_________________
A backup a day keeps DR away.

I can't get out of level F though


^L actually seems to indicate something about the preamp:

Donor head stack:

GALAXY4D - 1_Disk S-6D 11-03-06_17:08
Built for GALAXY4D,P
ITKIN/YUMA,REDBACK,Agere7531 PreAmp,InternalSpin,MCKINLEY_DT_ST,
OneToOne,4Disk,220 Servos,7200RPM,8Pole,133MHz,MOR_ON

so it looks like an Agere 7531 preamp IC (again, this is the donor head not the original).


Original head stack:
GALAXY4D - 1_Disk S-6D 11-03-06_17:08
Built for GALAXY4D,P
ITKIN/YUMA,REDBACK,InternalSpin,MCKINLEY_DT_ST,OneToOne,4Disk,22
0 Servos,7200RPM,8Pole,133MHz,MOR_ON

The bad head stack is just sitting on my desk, so I just screwed it into the bare PCB, aligned all of the contacts, and powered it on. The output of ^L is the exact same output as when I don't have the PCB connected to anything at all...so it looks like I might have damaged the (already bad) head stack after removing it from the drive. Awesome, so now I guess I'll never know what the original preamp was.

Anyone got any other ideas on how to identify the preamp?


Thanks!

Unfortunately the top platter is now scratched in two places: over where the heads park and also about mid-way out. Not looking too great for recovery now.