Yes, I suppose he wanted to say that drive spins up and calibrates but for sure it cannot be identified in bios. Most of end users say "bios/computer detects (see) the drive" but that often doesn't mean it is fully recognized. Just like statements: "it works but clicks", "it's good but not working" etc.

You are right.
It's spinning but not working, sorry for the wrong answer. It worked until new reboot.

Looking better at two PCBs I would say that those PCBs are not compatibile beacuse of difference in the components. Maybe the preamps are not the same and use different voltage, resistance and capacity. To be sure he must use the same PCB as old one just to avoid possible incompatibility of that part of PCB.

Hm, what do you mean with "worked until new reboot"?

I was able to read Data after flashing EEProm. But after reboot, I wasn't able to do so. I can't either connect with WDR to reflash ROM.

It's spinning, an I can hear some noise from the heads. But I'm not able to connect via WDR. I'm going to use the external programmer and flash the ROM.

Well, I'm now lost in all your posts with not so clear infos and descriptions.

For the non working drive (new) issue let's start from this:

You said that hdd was working until reboot so my question is: with which one pcb and which one ROM content was working until reboot.

Do the drives have to bre recognized by BIOS to work properly with WDR?

It worked with new PCB with old ROM content on new drive.

The pcb is not bricked because it spins up the drive.

If this really happened (with different ATA version!?!?!) I suppose the drive made a changes in firmware (like SMART modules) with bad adaptive save settings so the modules are badly saved and maybe some of them or even tracks damaged.

What can also be problem is that because of different (noncompatibile) adaptives in rom the new drive made a phisical damage on platters/heads.

You should try to write back original content to rom on the new drive pcb and if there is no damaged modules/tracks/platter/heads it should work.

As I said before to him "You can not do anything without tools, knowledge and experience. Sorry for saying but you have nothing of those"

.......

But how to fix the new drive when he doesn't know anything about how hdd works and don't have tool to diagnose what is wrong with it. It seems to me that this is neverending story because from one bad drive he now have two bad drives and if he goes on with "fixing bad drives" he will soon have more bad good drives.

So I really thinks the best solution for him is to learn about drives and experiment with lot of good drives before try to fix a bad ones.

All what he achieved is to read/write rom content and made a good drive not working anymore. I'm sorry to say and don't want to be rude but s..t happens especially because of lack of knowledge. I know that because I still have my first Maxtor 6E040L0 which was good until my novice "experimenting" with drives. I keep it just for remember me on my first and wrong steps.

So I repeat, he should try to write back original content to rom on the new drive pcb and if there are no changed modules or damaged modules/tracks/platter/heads it should work.

People shouldn't do things thay don't know and if they do, must be prepared on consequences.

I'm interested to know how drive gonna act with original rom content.

I will answer later. But for now, I reflashed ROM with external programmer and HDD works. I copied 1.6 GB Data an calculated MD5 hash. It fits the original file.

I will thank you for your advise, Spildit.
I wasn't able to connect to drive through WDR. Maybe it would work with another PC-Mainboard. Mine is an old Pentium 4 with installed Windows XP.
Of course, I read out the flash before erasing. Its content fits to the old ROM, which I wrote to the new PCB.
For now, I will end working on this.

Thanks. It was very informative for me and I learned a lot.
Just for the sake of completeness, I attached a photo from PCB with desoldered ROM, so you can see the connected pads VDD, HOLD and WP from SST25LF020A.
Thank you for your time and advice.

Ok. So long!

It seems that he didn't made any researches...
So, without the ROM...the PCB it's like a computer without it's OS. If you screw the OS, you won't be able to use VSC because those are handled by the routines inside the ROM(OS).

I guess because of busy state. Anyway, I'm glad that the new drive survived.