ST3500620AS PCB/Rom Swap = No Spin, Help Diagnose Problem

[bcometa]

Hello forum,

I have a st3500620AS 7200.11 Seagate 3.5" sata drive with burnt pcb. Got almost exact donor pcb (only difference is flash chip is "hynix" rather than "samsung") - same number, firmware, controller, smooth. I swapped rom chip (top left corner marked with arrow), powered up drive, nothing. No noise at all. It does the same thing if no ROM chip is installed on PCB. Using hot air gun to move chips, tried 3 times to make sure it was aligned properly and well-seated. I also tried donor PCB with it's original ROM chip installed, drive spun up but clicked lightly, as expected with wrong donor ROM chip/PCB installed.

So my question is, does the flash chip being hynix make this pcb not compatible? Any ideas?

(donor on top, patient on bottom)

(donor on top, patient on bottom)

Thank you for your time and help!!

[granaryloaf]

So my question is, does the flash chip being hynix make this pcb not compatible? Any ideas?

No it doesn't.

[pcimage]

The "flash chip" you refer to is the RAM, makes no difference what make it is.

If you can get terminal access via the serial interface, see what output you get. If the ROM is not blown then I suspect you'll get "preamp type 00 not supported" (or similar).

Judging by the amount of damage to the original PCB, then a blown preamp is quite likely

I would say this case is now beyond DIY, and pro intervention is required if you want to see your data again.

Whereabouts are you?

[bcometa]

Thanks for the quick response!

Just rehooked up and there is terminal connection. Not sure why but it's spinning now, with the original rom chip and donor pcb, but clicking softly and giving LED error in terminal.

Gets "ready" after about 10 seconds, serial/model/FW are identified and loaded correctly (except LBA = 0), I can move around in terminal, but trying just about any command gives LED message along with soft clicking.

I don't think this is typical 7200.11 busy error because of the clicking -- that error doesn't usually "click" -- right?

Client now told me that burning happened after drive was already not showing up. "Drive wasn't working, friend hooked up to computer and then burning smell."

Would the drive spin up if the preamp was bad (but the head just can't control itself properly)?

Thanks again for your help. FYI.. in USA, but client isn't willing to spend more than $300 so I doubt it's worth your time.

[hddguy]

Gets "ready" after about 10 seconds, serial/model/FW are identified and loaded correctly (except LBA = 0),

I suspect spindle also stops. the ID is made from ROM not SA.

Very likely heads are bad, or other physical problem (preamp?)