Thanks for the screenshots. As I expected, they show that the drive model identification is
not what I would call "completely garbled" - some parts are completely correct e.g. "424040M9A".
The text before & after that part (including "Hitachi", as you mentioned), varies a little in the outputs from the different utilities perhaps due to ASCII "control characters". Personally, I would be checking the
true result of an Identify Device command in MHDD (or similar), to see
exactly what hex is being returned to the host for the drive make & model info.
Leolo wrote:
I have visually inspected them and I see nothing wrong or abnormal. What is the procedure to troubleshoot the IDE pins?
Several approaches are possible... Personally, after getting a better view of the data using MHDD as I explain above, I would
start by using an oscilloscope, while doing disk reads - checking the low & high voltage levels and transition speeds on
all relevant interface signals (not only data).
As an example, further checks would then include seeing if the contents of all ATA registers seem to be affected - or is this just affecting the data buffer? As with all troubleshooting, the better you can be specific about
exactly what is being affected, the easier it is to then identify which components are on the list of "suspects".
However based on the exact form of that corruption, I am not convinced that this is a
pin problem. Unfortunately without the drive here, I could waste time making lots of wrong guesses, whereas with the drive in front of you, the answer would be much quicker.
Leolo wrote:
Also, why does the DOS-based Hitachi Drive Fitness Diganostics pass the drive as healthy so easily??
Shouldn't the test software be a little bit more strict with the problems of my drive?
This is a classic example of why you shouldn't (can't) rely on a "good" diagnostic result from any test - in fact I'll use this example of the misleading "Hitachi Drive Fitness" result, when I teach my next troubleshooting class

.
As I explained above, the fault is not affecting all I/O. So all you need for an apparently good result, is for the fault not to return an obviously "wrong" answer.
For example, I expect that a "read test" on that drive will not fail - it'll probably just return partially wrong data (which is also why the partitions aren't correctly recognised), but any kind of "read-only fitness test" software won't know that the data which is read isn't the expected data! If you used test software that does a write-read-compare across the IDE interface,
that test should fail, but obviously that's destructive to some data on the drive. (Also, since some bytes crossing the interface are being corrupted, I do
not recommend that you attempt any write commands to the drive - perhaps bytes written to the LBA registers are also being corrupted (see below) and then the data would end up being written to the wrong place!)
Some drives
will do such a write-read-compare to the SA during a SMART test - but since the data pattern used for the write & read does not pass across the IDE interface in that case, then again, that test would still pass even with this type of fault! Are you starting to see how easily you can be misled by a test "passing"?
It all depends on the test that is being run, exercising the defective part
and having a way to detect all possible failure (i.e. incorrect result) mechanisms. That's not trivial for software to achieve this (although the quality of diagnostic software varies significantly) , and is especially to detect for some types of partial problem, as you have on this drive. Over the years, I have seen many, many pieces of diagnostic software which do not detect specific faults...

For you, I suspect that the easiest solution (if you can't, or don't want to, find the electronics fault yourself) is to replace the drive's PCB, as well as moving whatever drive-unique info exists on that PCB to the replacement. Others on this forum may be able to advise on how to do that, or may be able to do the job for you.
Hope that helps
