Switch to full style
Data recovery and disk repair questions and discussions related to old-fashioned SATA, SAS, SCSI, IDE, MFM hard drives - any type of storage device that has moving parts
Post a reply

ST31000340NS engineer mode

May 29th, 2010, 21:19

Yep its this old chestnut again........

I have 3 of these ST31000340NS drives
PN: 9CA158 - 503
FW: SN05

one has gone 'bad'
On the good ones , when power is applied , the head seems to "load" rather noisily, unload, then reload. (a sort of double click) , before the drive goes online.

On the bad drive this cycle is continually repeated, but the same sound.

I cannot get into engineer mode via serial for more than about 3 seconds

(FW SN05)
LED:000000CC FAddr:0024A7E5
LED:000000CC FAddr:0024A7E5
LED:000000CC FAddr:0024A7E5
F3 T>
F3 T>
F3 T>
F3 T>
LED:000000CC FAddr:0024A7E5


It seems that Seagate have applies some sort of "fix" that prevents the PCB entering into engineering mode if:

1. The boards are removed from the Platter shell
2. A card is installed between the drive motor connections and the PCB
3. A card is installed between the head connections and the PCB

Unfortunately the PCB just sits there, this also occurs on the "good" functioning drives as well, that is to say following the above 1.-3 also does not work for getting good drives into engineering mode.


Direct PCB swap does not work (obviously), but when it is performed the sound from the defective drive stack is different, which may indicate the heads are actually ok (out on a limb here ), and it is the initial "service" area that is trashed.

Cannot apply updated firmware to defective drive, because drive has to be ready and online.


Any pointers in how to get the Engineering mode on line without the drive shell attached?

Re: ST31000340NS engineer mode

May 30th, 2010, 3:36

OK , LOL

we are good..... , must have been tired yesterday.

Just managed to pull the drive back, and all the data is still intact.

But I think we can now safely say that "head knocking " in not ALWAYS a sign of bad heads or broken hardware, but is also the domain of shitty poorly Q.A'd Seagate software.....

I have to add that i am really shocked at how poor the quality of Seagate drives have become.....

Re: ST31000340NS engineer mode

November 24th, 2010, 6:50

HI, i have exactly the same problem as above, i have tried the CA-42 cable, and the USB RS232 cable but cannot get into engineering mode. How did you manage to fix urs. Your help will be appreciated big times. Thanx

Re: ST31000340NS engineer mode

November 24th, 2010, 17:06

Does this help?
http://www.msfn.org/board/topic/129551- ... 0cc-state/
Post a reply