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Hard disk bad track 0, date of manufacture codes

A

Allen

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I've been trying to fix four 30 MB ESDI hard disks for an IBM PS/2 Model 50Z (another one). The original disk was bad, and so I acquired three more (two were new old stock, and one was used). All of them come up with invalid media--bad track 0 errors when I try to format them. Some give me error codes 1780 or 1790 on startup, but this isn't always consistent. The disks in question are WD-336R (three) and WD-336RT. Internet searches didn't help. If a hard disk has a bad track 0, does this mean there is no fix?

One last unrelated question: I have a Model 30 PS/2 (8086) and I'm trying to figure out the (roughly) the date of manufacture. There are no actual dates on the system, but the cover has an unusual date stamp--see attached picture. What is this date? Only the day is clear to me. The year must be 1987 or 1988, when these PS/2s were sold.
 

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A brief of what I did

A brief of what I did

I suppose I should go into more detail on what I tried. First, there's nothing wrong with the ESDI controller or the PS/2 itself (I tried a good hard disk in this particular PS/2, and everything went fine). The system sometimes has trouble recognizing the type of fixed disk (hence error codes 1780 and 1790), but this isn't always consistent. The system tells me this when I try to view or run configuration with the reference disk.

Low-level formating with the reference disk gave too many sector errors. I've tried all possible options with the FDISK and FORMAT commands in DOS. Nothing seems to work. There are jumpers on these disks, so I tried closing a few. Sometimes I would get strange noises with some positions closed, others didn't seem to do anything (if any of you have a working WD-336R or WD-336RT, let me know if you have any particular jumper settings on yours).

I'm tired of dealing with these disk--I just want to be absolutely sure there is nothing else I can do. That's why I asked if "bad track 0" means a hard disk is dead, forever.
 
Spinrite

Spinrite

There's a tool called Spinrite out there that does low-level formatting, above and beyond what some controller's low-level formatter do, but I've never used with an ESDI drive. (And also, unfortunately, don't have a copy anymore )

patscc
 
Yes, track 0 errors are bad news; that's where the master boot record is kept. I assume you're doing a low-level format, not the FORMAT command type.

It could be that the whole disk is bad. If I remember correctly, the format operation starts at cylinder 0--if it fails, the formatter calls it quits right there.
 
Can't use Spinrite, formatting doesn't work at any level

Can't use Spinrite, formatting doesn't work at any level

I tried using Spinrite, but it couldn't do it's analysis (or anything else) because the disk wasn't formatted to DOS--and that is the problem, I cannot format any of the four disks.

I tried a low-level format using the PS/2 reference disk, but the program stopped because there were over 800 bad sectors, so I could not finish a low-level format. I could not start a normal format (using DOS command FORMAT) because of a bad track 0.

I appreciate the efforts in decoding the date of manufacture. I wish IBM made it simple to understand date codes.
 
Allen said:
I tried using Spinrite, but it couldn't do it's analysis (or anything else) because the disk wasn't formatted to DOS--and that is the problem, I cannot format any of the four disks.

I tried a low-level format using the PS/2 reference disk, but the program stopped because there were over 800 bad sectors, so I could not finish a low-level format. I could not start a normal format (using DOS command FORMAT) because of a bad track 0.

I appreciate the efforts in decoding the date of manufacture. I wish IBM made it simple to understand date codes.
Click to expand...

If the LL format failed from the reference disk, there's no point in following up with DOS FORMAT.

Out of curiosity, do the drives you're trying to format have the terminator resistor packs installed? Unlike floppy drives, which can get by without them, they're pretty important to ESDI functioning.
 
+1 on the terminator packs.

An alternative would be to download DR-DOS and use it to partition the drive. You can start the partition at a different cylinder than 0. I've had luck in using that with drives that reported a bad cyl 0.

But... with your drive failing the low level format it's either a terminator pack is missing or it's toast. As a last ditch effort to use the drive, you can try to resolder the connections on the cable and on the board where the heads plug in. Sometimes the solder cracks.

RJ
 
Terminator resistor packs

Terminator resistor packs

I'm no electronics expert, so I am unfamiliar with terminator resistor packs. I tried looking for pictures on the internet for these, but nothing was clear. Attached are two pictures of the board of one of the ESDI drives. There is nothing interesting on the other side of the board. If these drives have terminator resistor packs, I assume it would be on the board.
 

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Jumpers

Jumpers

A picture of the jumpers is attached. I could not find any documentation about this drive (WD-336R and WD-336RT) online, so I couldn't find any information about the jumpers. I did close two jumpers at a time (from top to bottom) and restarted the computer. At least three times, I got some real strange noises from the disk. But in all five tries, it didn't seem to change the status of the drive.
 

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Depends on PS/2 model

Depends on PS/2 model

The hard disk connector connects to a socket on a fixed disk adapter card connected to the system board (Model 50), but this depends on the PS/2 model. Some PS/2 models use a cable connected from the system board to the hard disk.
 
Board

Board

Ok, my take on it is that the drive you have pics posted from plugs into a board, and therefore has no termination on it. The 'second stage', for want of a better word, controller probably provides any neccessary termination.
You're trying to use the drive with the plug-in type board, right ?
patscc
 
patscc said:
Dumb question, you've tried another controller?
Click to expand...

When referring to "DBA" (Direct Bus Attachment) ESDI, all of the controller electronics are on the drive itself. DBA ESDI is also a single drive system, no primaries, secondaries, or chains to worry about turning termination on or off. The following microchannel PS/2s are DBA ESDI either being present or a stock configuration (but can also have that supplanted by another interface like SCSI):

50Z (on riser card)
N51SX (smaller notebook-class dimensions)
N51SLC (ditto)
53SLC3 (on riser and cable, obsolete vestige, stock is planar IDE)
55SX (on riser and cable)
CL57SX (smaller notebook-class dimensions)
70 (on riser card)
P70 (from planar cable)
90 (obsolete vestige on 8590, planar connection x 2, connections removed on 9590)
 
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