Trying to get output on Seagate serial port

[JTT]

I'm having problems getting any response from the 4-pin serial port on a Seagate ES.2 drive and would appreciate help getting this to work.

I'm using a USB-to-TTL adapter with wires connected to the 4-pin serial port (Tx, Rx, GND). The adapter I'm using is this one:
https://www.waveshare.com/usb-to-ttl-b.htm

Try as I may, I can't get any response from the drive(s) I've tested it with.

So far, based on everything I've found, here's what I've tried:
1) I've used both PuTTY and Realterm, and made sure I have the right COM port.
2) I've tested with a jumper between the Tx and Rx leads to be sure I can send and receive through the adapter. I can see my keyboard entries fine.
3) I've connected power to the PCB via the SATA connection (and with/without the 3v/5v jumper wire from the adapter).
4) I've switched the Tx/Rx leads to be sure I didn't have them backwards.

However, even with it all seemingly connected properly, I cannot get any response from the drive (using 'Ctrl-Z'). I should also ask whether the drive has to be a known-good drive since my initial testing has been with a couple of 'donor' drives. I swapped the heads from them to my patient drive, but the donors were working when I got them, so their PCBs should be okay.

Any help on what to try would be great. Thanks.
JT

[pepe]

Hello,

the problem is likely related to Vccio, which is 1.8 or 2.5V on your drive, depending on the family (an exact model number would help...)
No such drives used 3.3V+ as Vccio. In theory, if your drive used 2.5V, you should have seen some garbage on the serial port IMO, so it is more likely 1.8V.
Also, some firmwares do not send any diag messages during powerup, so that might be another cause of the silence.


pepe

[JTT]

Thanks pepe..
This drive is a Seagate Constellation ES.2 ST33000651NS. Since the label has 5V/12V printed on it, it hadn't occurred to me that it may be 1.8V or 2.5V. That said, I also tried it with the power plugged in via the SATA port, if that should have made a difference. Still, there's no response either way.
Thanks again...
JT

[pepe]

That said, I also tried it with the power plugged in via the SATA port

excuse me, how did you power the drive before?

[img]

Thanks pepe..
This drive is a Seagate Constellation ES.2 ST33000651NS. Since the label has 5V/12V printed on it, it hadn't occurred to me that it may be 1.8V or 2.5V. That said, I also tried it with the power plugged in via the SATA port, if that should have made a difference. Still, there's no response either way.
Thanks again...
JT

If you are not "Lucky Luke" you could get the "SMI init or training failed" error message on terminal - that means you killed the PCB and you need to swap it.

BTW I'm curious too, as Pepe asked: how did you power the drive before?