I have a Seagate 7200.12 drive that is showing up as a "st_m13fqbl" with 3.86GB file size. Beyond that I haven't figured out much else with it because I cannot for the life of me connect to the hard drive with a serial connection. All I have been able to get from Putty is some random characters mixed in with block like characters, which I assume are just electrical noise (they occur when changing wires around the most). The drive spins up when powered and doesn't make any clicking or odd sounds. The data is fairly important, but not enough to spend a grand on professional recovery.

Model: ST31000524AS
Firmware: JC45

For tools to connect, I have a USB to TTL Serial and RS232 to TTL adapter. For the RS232, I have a GoldX PL2303 chipset adapter and an old Windows XP laptop with serial port. I have tried connecting with the PCB attached, unattached, and HDD data pins covered to no avail. I have seen there may be a need to short read pins, but it seems that people were getting some sort of output before that, so I don't think that is my issue.

I have another identical drive that also experienced issues around the same time, except it is clicking and shows up as RAW format with correct size, but I was able to recover data just using software. I have tried to connect to this drive as well to see if it will work and it still does not.

For wiring to the drives - I am using the two pins closest to the SATA port for RX/TX, and I've reversed them each time to make sure that I don't just have them backwards. I am using a common power supply or make sure to use the ground pin (3rd from SATA port) if not using a common power supply. For powering the RS232 to TTL adapter, I am using the orange and black wires from my PC's power supply to power the board (HDD also powered from computer). SATA is never connected during any of this.

I've read more forum posts than I care to admit and am at the give up point. Hoping someone here can spot the error I am making or give me anything else to try. Thanks!

There are companies (several on this forum) that would likely take care of the problem for less than you think, providing you haven't already taken it to bits. Just something to consider if the data is actually important. I know it's not the answer you were looking for but its one you may have wished to know sooner than later. Some of these shops seem to be working for peanuts these days.

Any idea roughly how much? The drive is my neighbors that I'm trying to help out. I know he got a quote for $850 that he wasn't interested in, but I think he'd bite if it could be done in the $100-$200 range.

And for the drive, I don't think I've done anything destructive since I can't connect to it. Only possibility would be if I accidentally shorted something that I didn't realize, but I've tried to be quite careful with that.

Getting that size and type that you listed is consistent of a head failure in the drive.