The HDD was in good condition in an old CNC-Machine, operating-system is DRDOS 5. I took it out to make a backup of the data. That was not a good idea. I connected the HDD to a Core2Duo PC with a legacy IDE-connector onboard. That PC has far more bios-options for a HDD than a 386 or 486 and I think that killed the HDD. I did an autodetect, the HDD was not detected. After that I tried with a Pentium 2 PC and at last with a 486, of course with correct parameters. Not detected. Then I took it back into the CNC-Machine but it was not detected either: "ERROR ENCOUNTERED INITIALIZING HARD DRIVE 0"

I also looked at the solder joints and I disconnected and reconnected the PCB twice to eliminate contact problems.

My boss is not amused!


any help would be highly appreciated

Did you change anything else like the jumpers. When you put it back in the CNC machine did you use the same cable and the same connector. Double check for the drive for bent pins and ribbon cable direction. I take it the drive still spins, any other odd noises.

If your boss is not amused it may be prudent to call a pro before things get worse.

_________________
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@CF99, be aware that drives of that era were using CHS mode rather than LBA mode.

However, I can't see how anything you did could have resulted in the death of the drive.

Your drive may have a serial diagnostic port:

https://www.acelab.ru/dep.pc/doc.pc3000dos/050530.001/Pcconer.pdf

Perhaps you could record any error messages?

_________________
A backup a day keeps DR away.

@Lardman: I only changed the master/slave jumper. CNC connectors and cables cannot be changed without soldering but if the hard disk is not recognized in any environment, I don't think it can be because of that. The drive spins and the sound seems to me quite okay: A clickedyclack when starting and some seconds later brrrtbrrrt then silence and brrrtbrrrt and so on.
A CNC professional will be looking at the machine in the next few weeks anyway (2000 Euros just for the travel costs ) and he will then put in another hard drive with a fresh system. But I would like to repair the old hard disk beforehand so that the professional only has to take care of the other things.

@fzakbar: I am aware of CHS now and put in the correct parameters (But at first I used wrong ones).
"However, I can't see how anything you did could have resulted in the death of the drive." Thanks, that is comforting, I will show it my boss... Actually I "repaired" the CNC two weeks ago just by putting the HDD cable on and off. But that does not help anymore and I think the fault is something different now.
My model CP30104H is not mentioned in the russian document, therefore I didn't get deeper in it.

@all: I bought a drive with bad sectors. Same model but different PCB Numbers. It will hopefully arrive within the next days. I hope I don't make things worse when switching the PCB. Here are photos of my PCB (PCB1) and the one I have bought (PCB2).

Were you pulling the power or the data cable.

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I pulled both cables.

Sorry to tell you but that means the drive is NOT ok.
Also don't try using that replacement pcb. At least not for now.

Isn't this the only thing I can still do as an amateur? And isn't it relatively safe to use a fairly similar board?

@CF99, your model has the same "technological" connector as described in Section 2. on page 3.

The document states that you need a "PC-Conner adaptor". However, I suspect that this is merely a 5V-to-12V RS232 adaptor designed for interfacing the drive's 5V TTL levels to a legacy RS232C COM port. Instead you could purchase a 5V USB-TTL adaptor and experiment with the output pins. One will be Tx, another will be Rx. I expect there would also be pins for the ground and supply voltages. I could help you to determine the pinout if you have a multimeter. We could experiment with your donor PCB until you find the correct pins and baud rate, etc. The board would not need to be installed on the drive during these "explorations".

You can (almost) see the adaptor here:

https://axon.kz/image/pc-3000_dos_4.jpg

https://axon.kz/pc-3000_dos.htm

_________________
A backup a day keeps DR away.

Hello fzabkar, thank you for Your informations and Your offer! I may come back to it later.

I have received the donor HD in the meantime. Changing the PCB didn't help.

I have spoken to the CNC professional in the meantime: He says the HD has been modified to work only in the CNC and it would not be readable in any DOS PC. I'm not sure if I can believe that because the CNC professional is a master of his trade but not a computer expert. However, I read a similar claim in a Russian CNC forum.
Tomorrow I will put the old hard disk into the CNC again and try to get into the bios there and compare the parameters. That's not easy either, the CNC manufacturer has changed some of the keyboard commands and made it (almost) impossible to connect a normal keyboard.

When you put the drive back in the CNC machine, listen carefully to the spin up and initialisation. If you get the brrrtbrrrt sound that means the drive is damaged in some way and data access would be impossible.

By the way, the drive in good working condition might not be visible to the Windows os but would still be accessible using the correct software tools.

Good luck!

The hard disk is running again and all the data is still there!!! I bent the rather stiff cable between the hard disk and the circuit board differently and now the disk is recognised again. (The cable is very tight between the hard disk and the motherboard and presses against both) Even though I still haven't found the actual fault, I'll leave the disk alone from now on.

Thanks to all of you for the comments and information!