That's interesting, I wonder if it was suffering from stiction and heating it up helped with that... Mines does not have that issue, but my ST-125N does, maybe I should try next time it doesn't start to heat it up just a bit to see what happens.

I don't beleive it was messed with, at least on the side of the drive there's a small sticker with some info on it saying : 3.4-13-A1 N5SLARNAS17A X9037 That 3rd line corresponds to the 9037 date stamped on the PCB, and the first line has to do with the firmware, as it says 3.4 and 3.4/048 is the firmware version speedsys and MHDD reports. No idea what the middle line is. On the newer one there's only two lines N5SLARNAS19 4.1-14-A1 The date isn't printed on it, the stamp on the PCB says 9049. Speedsys/MHDD says its firmware is 4.1/064 which also corresponds. The have very similar seek times within margin of error. In my file I have (Yes I have made one since a few weeks now, its quite usefull) Avg 35.91 Max 57.41 Random 28.76 TtT 9.21 Random Access 39.94 for the older one and Avg 35.6 Max 57.24 Random 28.98 TtT 8.17 Random Access 39.6 for the newer one. I actually watched most videos of ST-157A drives I could find yesterday, and sure enough, they all seemed to have the same seektest as the newer one (When the videos had the seektest included, which many did not)

I looked a bit more, and I found other videos where the drive sounds like my older one, here : kzfaq.info/get/bejne/m7qPZpCa2tSaomQ.html at 1:07 and also here inside an old PC kzfaq.info/get/bejne/n5lybKh52KjHc5c.html at about 0:17 I checked on ebay listings to see what firmware versions I could find, and I saw a lot of 4.1 and 4.2 ones, with 2 where I could see 3.4 (Both had a good enough picture of the PCB to see the date, 9024 and 9044). Seems like the 4.2 ones are the ones having the "CAUTION: DO NOT LOW LEVEL FORMAT" sticker that the 3.4 and 4.1 ones do not have. I did not see any ST-157A without the -1 though, they must be really rare.

@@arnlol Actually I don't know which firmware versions my drives have. I will check that when I'm back home and get back to you. But I'm pretty sure none of my drives does the slow seek right at the beginning of the seek test. I never heard that.

Here are the firmware versions of my drives (first number being the date as stamped on the PCB) 9109 4.1 14 A1 9049 9.7 14 A1 9050 4.1-14-A1 (the only one using dashes between numbers) 9146 4.2 14 A1 9049 4.1 14 A1 9122 4.2 14 A1 9115 4.1 14 A1 Interestingly 9049 has a 9.7 firmware. But this is one of the dead drives (head crash) and I transplanted its PCB to the first (9109) drive because 9109 had a PCB that tended to overheat (and it had a lot bad sectors though their number seemed to increase with every run and the PCB heating up and when I cooled down the two squarish chips next to the ribbon cable that goes to the head reading performance improved slightly). This resulted in less bad sectors for the 9109 drive though still to be considered unuseable. Anyways, despite the different firmware versions the 9109 drive worked so I wonder if the firmware differences are not relevant for merely reading data from the platters.

It's the same as my st 157n

Seagate changed the BIOS several times during the production of the ST125 and ST157. The stickers were also affixed like this from the factory on every Seagate drive that had the option, all the way back to the ST-238 and possibly even earlier. The only "real" way to tell the difference is to look at the part number of the stepper or measure the resistance of it's windings. The faster drives have low impedance steppers.