PC-3000 Forum

I've read through some old post with this error but still didn't get any conclusions, any answers.
Now i am encountering this myself. Really want to know solution to this

I got a Seagate 500GB laptop drive

Model : ST500LT012-1DG142
Serial : S3PNCWJX
Firmware : 0002
Capacity : 4 GB (8 089 950)

The drive came in clicking - So i changed the heads. The drive then click twice then spins down. Got RDY state. But cannot do anything. Any option will lead to
Spinup Failure
ServoLoopCode=0x0000007F

I thought it might be the Heads problem so i swapped the heads back to original donor and it came up fine. So it was not the heads problem
I procced to change new set of Heads> This time the drives comes RDY and i can enter sectors. But upon backing up Modules. The drive hanged and got to the same state again
Spinup Failure
ServoLoopCode=0x0000007F

Now i am changing 3rd pair of heads but the errors stays the same
So if anyone came in with a solution can you guys help me out!
Many Thanks!

This must be some problem with ROM i believe. After changing heads 3 times, and changing platters to other case. I realized something is messing with the spinning motor.

When changing heads. The drive still clicks 2 times then stops. Reason i think is the motor doesn't even want to spin fast enough to let the heads get on the platters

Then i tried changing platters. On the 1st turn on of the drive. The drives ID normally, and you can even read sectors. But as soon as you turn off the drive (to change some settings) Turning it on will give it back same error state as before

One more thing to add. I tried turning on the PCB only, without the drive. The error persists. It is like the error is infused into ROM

Can anyone help??

Hello.

Fail Servo error messages in terminal means that heads can't pass internal heads test, as a result they doesn't allow to read even the most powerful magnetic signal from the surface - Servo labels.
So, current heads are damaged or/and they are incompatible or/and surface is critically scratched or/and ROM is not native for this drive.

Check heads back in donor drive. If they work, heads are not compatible.
If they don´t work you medie damage in patient or your change procedure killed them.