WD2000BB head alignment

[maddin]

Hello,

I have swapped the head of a WD2000BB drive from 2005 and I am not so familiar with that one. According to the matching-guide from Donordrives the drives are compatible except the microjogs which I could not determin as the patient never come that far and the PCB alone didn't come ready...

The drive clicks a few times, stops and repeat the clicking so I am not sure if that is related to wrong microjogs, head alignment issue or I just screw up and kill the head while swapping it (unlikely as to me the swap went smoothly).

I know I can test it by reinstalling the head in the donor but what if this old model has the head alignment issue? So I want to make sure first if I need to get the head alignment working on that drive first...

[Lardman]

That's a caviar drive not a marvell. Have you got the full info from the patient and donor ?

[maddin]

Patient WD2000-00GUC0, DCM HSBHYTJAA, S/N WCAL82500164, DOM 09.04.2005 in Thailand
Donor WD2000-00GUC0, DCM DSBANTJAA, S/N WCAL79051036, DOM 19.06.2006 in Thailand

Except the age differnece it looks like a good machtch but I could not find any closer in date.

So on Caviars there are no mocrojogs or do they just not matter? I don't do DR so long and it's my first headswap on one that is so old.

[Lardman]

Could really do with the head map info. I assume you tried kernel mode to get at it ? Do you have an eeprom reader you could read the rom with?

[maddin]

Could really do with the head map info. I assume you tried kernel mode to get at it ? Do you have an eeprom reader you could read the rom with?

In a desperate attempt I was hoping that maybe head 0 will time out and head 1 will read a copy of the SA I waited a bit and indeed i got DRD and DSC but I could not identify the family. And I have no TB Eagle in MRT. I selected one of the old families and enter Kernel Mode.

First I got asked for heads, cyl. and SPT but cyl. and SPT where grayed out and prefilled with 32 and 900. I entered the 5 heads as recogniced in the log and klicked OK. Then I try to reidentify the drive and I got at least the Model and FW-version but no serial nor size so I guess the heads don't read the SA at all.

I cant even backup the ROM or access stuff in the RAM like "Edit HDD ID in RAM".

If you like I can read the ROM with my Revelprog and post here the data.

I also tryed the donor-board with the patient ROM - same result.

[Lardman]

My ide days predate me having PC3K and I just used to keep swapping heads until something worked but there were plenty of donors around back then. If you read and post the ROMS I'll take a look at them here - but I'm not sure where the head map is stored in those drives, can't hurt too look though.

[maddin]

I forgot I still have an old 3.3V reader here so I did not need to wait till monday - that's the patients ROM.

Attachments

20210821_200626_FLASH_25010.dat.gz

Patient ROM

(123.25 KiB) Downloaded 781 times

[fzabkar]

The head map is at the end.

Code:

Offset(h) 00   02   04   06   08   0A   0C   0E

0001FFD0  2006 0006 053B 0000 0000 0000 0000 0000
0001FFE0  0000 AA0A 0000 0000 0000 0000 0000 E0FE
0001FFF0  5A5A FFFF FFFF FFFF FFFF FFFF 0000 A94C

[fzabkar]

These look like adaptives for 6 physical heads:

Code:

Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F 20 21

00015CA2                                                                                               00 40 66
00015CC4  C0 00 39 80 90 3B A2 C0 80 02 F9 09 F3 31 5B 2F 1F 05 04 70 0C 27 46 31 80 78 05 07 07 08 03 00 40 7E
00015CE6  C0 00 27 80 A0 3B A2 B0 80 01 FA 06 F1 28 56 26 1D 03 04 70 0C 27 46 31 80 78 06 08 08 08 03 00 40 6B
00015D08  C0 00 39 80 90 3B A2 C0 80 02 FA 0A F6 30 5B 2B 1E 03 05 70 0C 27 46 31 80 78 06 05 06 06 03 00 40 77
00015D2A  C0 00 24 80 A0 3B A2 B8 80 00 FA 05 F3 2B 59 2A 1D 04 03 70 0C 27 46 31 80 78 05 06 07 06 03 00 40 64
00015D4C  C0 00 21 80 A0 3B A2 B0 80 01 FA 07 F0 2D 53 2C 1C 05 05 70 0C 27 46 31 80 78 05 07 08 06 03 00 40 80
00015D6E  C0 00 20 80 A0 3B A2 C0 80 04 FD 13 02 36 67 29 21 02 05 70 0C 27 46 31 80 78 05 05 05 05 03

This is the entire adaptive module:

Code:

Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F

00015CA0                    0C 41 00 02 03 01 05 04 47 50        .A......GP
00015CB0  2E 30 4A 00 18 00 E4 00 F0 00 F6 00 00 00 06 19  .0J...ä.ð.ö.....
00015CC0  01 00 40 66 C0 00 39 80 90 3B A2 C0 80 02 F9 09  ..@fÀ.9€.;¢À€.ù.
00015CD0  F3 31 5B 2F 1F 05 04 70 0C 27 46 31 80 78 05 07  ó1[/...p.'F1€x..
00015CE0  07 08 03 00 40 7E C0 00 27 80 A0 3B A2 B0 80 01  ....@~À.'€ ;¢°€.
00015CF0  FA 06 F1 28 56 26 1D 03 04 70 0C 27 46 31 80 78  ú.ñ(V&...p.'F1€x
00015D00  06 08 08 08 03 00 40 6B C0 00 39 80 90 3B A2 C0  ......@kÀ.9€.;¢À
00015D10  80 02 FA 0A F6 30 5B 2B 1E 03 05 70 0C 27 46 31  €.ú.ö0[+...p.'F1
00015D20  80 78 06 05 06 06 03 00 40 77 C0 00 24 80 A0 3B  €x......@wÀ.$€ ;
00015D30  A2 B8 80 00 FA 05 F3 2B 59 2A 1D 04 03 70 0C 27  ¢¸€.ú.ó+Y*...p.'
00015D40  46 31 80 78 05 06 07 06 03 00 40 64 C0 00 21 80  F1€x......@dÀ.!€
00015D50  A0 3B A2 B0 80 01 FA 07 F0 2D 53 2C 1C 05 05 70   ;¢°€.ú.ð-S,...p
00015D60  0C 27 46 31 80 78 05 07 08 06 03 00 40 80 C0 00  .'F1€x......@€À.
00015D70  20 80 A0 3B A2 C0 80 04 FD 13 02 36 67 29 21 02   € ;¢À€.ý..6g)!.
00015D80  05 70 0C 27 46 31 80 78 05 05 05 05 03 00 2D 95  .p.'F1€x......-•
00015D90  26 95 26 95 28 95 29 95 2D 95 0A 0A 0A 08 0A 0A  &•&•(•)•-•......
00015DA0  67 04 30 04 2D 04 31 04 88 04 9A FE 00 00 00 00  g.0.-.1.ˆ.šþ....
00015DB0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
........
00015EA0  00 00 00 00 00 00 00 00 00 00 00                 ...........

[Lardman]

These look like adaptives for 6 physical heads
This is the entire adaptive module:
The head map is at the end.

Errr - Yeah, what fzabkar said I drew a blank with the tools I pointed at it Is the head map the same on the donor as the patient?

[fzabkar]

The head map is 0x3B = 0b111011 -- 6 physical heads / 5 logical heads / head #2 switched off.

Would WD2500BB be a suitable donor? It would be guaranteed to have 6 physical heads.

[maddin]

The head map is 0x3B = 0b111011 -- 6 physical heads / 5 logical heads / head #2 switched off.
Would WD2500BB be a suitable donor? It would be guaranteed to have 6 physical heads.

Not really sure why but I have troubles reading the donor ROM. I get from 5 reads 5 different results and they look quite random and I don't see destinct patterns as in the patient ROM. I also tryed to get the chip in the slot-in reader on the rusolute.

I would have a
WD2500BB-55RDA0, DCM: HSBHNTJAAN, S/N: WCANKF923368, DOM 16.04.2007 in Thailand
in stock but that is quite a lousy match - even worster then the WD2000BB I had used.

I guess the first question should be if I need to alogn the heads in some way on that drive or not - if head alignment ist not an issue on that model then I can just put the heads back in the donor and see if they work.

As far as we can see the patient-ROM seems to be OK and therefor the issue can be
- incopatibility,
- alignment or
- damage.

If alignment is no issue on in that model then we can at least eliminate one ot that points.

But I have another very bad feeling - could you extreact the serial number from that ROM please - the ROM had soldering marks not that someone had swapped the ROMs and forget to swap them back or is there no serial in that ROM?

[jono-ats]

Alignment is an issue.

See if you can read anything with hot swap. You might try changing the heads map on the hot swap donor to read H0 only before you recalibrate on the patient.

I'd be inclined to match NTJ from the DCM.

[Tomset]

usually, these disks (Cyll 32 Eagle) are deducted from the hotswap for each head by a bunch of donors.

[maddin]

What you mean by hotswap? I heard about a hotswap for the PCB but not for heads... Or do you mean hotswapping the PCB and editing the headmap in ROM or what?
I get the PCB ready but I can't access the ROM nor the RAM on that one.

[Tomset]

The ROM needs to be read from Safe mode only from the board.
Three jumpers.
SA also read from a hotswap, a compatible donor.

[fzabkar]

As far as we can see the patient-ROM seems to be OK ...

Every section of the ROM has a valid checksum except for the headmap. However, this is not unusual, and the headmap is otherwise OK.

https://forum.hddguru.com/viewtopic.php?f=1&t=33068

Would transplanting the donor's ROM adaptives into the patient improve compatibility?

[northwind]

No.
As said earlier, this drive is affected by head alignment and this NEEDS to be sorted out to get SA access.

To solve it, you need to hotswap the drive or play with the top lid position to see if that makes any change. Sometime it works, but you need to know what to do otherwise you'll end up with a nice ring on the platters.

PS. Yes, the 250GB drive is a good donor.

[jono-ats]

This particular family / model is sometimes tricky even for those of us who have tools like the PC3000 and know how to achieve re-alignment.

Matching heads and adaptives; hot swapping; creating hot-swap donors; backing up and working with the firmware and being able to work with a heads map are skills and experiences that are frequently needed for successful recovery.

You might be incredibly lucky and do a successful head swap and not contaminate the drive, and figure out a way to re-align it, but I'd estimate the odds of you being able to do this without bricking the drive at about 100 to 1.

If you are doing this for a client -- or if it is yours and you have data that you care about -- I recommend you outsource it to a pro.

[fzabkar]

This particular family / model is sometimes tricky even for those of us who have tools like the PC3000 and know how to achieve re-alignment.

Matching heads and adaptives;

I read Ace's docs but could find no mention of adaptives in the Caviar range. There doesn't seem to be any menu item for this purpose, either. The only "adaptive" items are the head map and firmware version. The module that I referred to earlier is not mentioned. Have I misinterpreted those 6 sets of numbers, or are they irrelevant, or did Ace neglect to analyse them?