Swaping PCB and ROM chip

[kevindanielbrown]

Hello everyone,

I have a 80GB WD800JB that I believe has a bad PCB and I'm willing to try to change the board myself before I spend $2,000 at a professional data recovery service. I've done a lot of research and everything I've read indicates that after swapping the PCB board out it may be necessary to transfer the ROM chip from the old PCB to the new replacement one. And everything I've read states this chip is the U12 chip. I have looked all over this PCB and don't see a U12 chip. This is an older hard drive (2003) so I suspect the ROM chip is elsewhere.

Could someone help me locate where the ROM chip is on this board?

Here is a link to a picture of the PCB:
http://ep.yimg.com/ca/I/yhst-1443758497 ... 18_2142860

I'm not very experienced with soldiering and what not so any additional advice would be greatly appreciated.

Thanks in advance for any help.

[msurgeon]

Shouldn't be necessary to swap ROM on this model unless you really like soldering. Just match drive model number exactly and the PCB should work. Incidentally, ROM is at U2.

[kevindanielbrown]

So I swapped out the PCB and now at least the hard drive is spinning up (it wasn't powering/spinning up at all before) but it constantly is making a loud clicking sound and after a few minutes of clicking it sounds like it powers down completely.

Any advice?

[Alexii]

Possibility of bad preamplifier. Need new heads in that case. Unfortunatly non DIY.
Another posibility - adaptives. Did u move eeprom?

[kevindanielbrown]

No I didn't move the ROM chip but I was told by someone else that as long as the model number etched onto the PCB itself is exactly the same (which is it) I shouldn't have to move the ROM chip.

[Alexii]

Drive model, not the PCB stamp needed to be matched to be able to work with no eeprom move. Thats if i understand Msurgeon correctly.

[kevindanielbrown]

I actually purchased two seperate replacement PCBs. One was a match of the drive model number and the other was a match to the PCB model number. I've tried both of them with the exact same results. Both allow the drive to at least power up but then the loud clicking immediately starts.

[Alexii]

Id move eeprom , and if it still clicks - blame preamp and call it a day =)

[msurgeon]

Did you match the entire drive model including numbers after the dash, e.g. WD800JB-75GUA0?
If you didn't then you will have to move eprom. If you did and the drive still clicks then the problem is with heads/preamp.

[Russwinters]

In my experience even if you match the model it may not work.

By matching the model you are hoping that the adaptives are "close enough".


Unfortunately this isn't always the case. On newer drives it is much more likely that it will not work (like 95% chance or higher)

[msurgeon]

I

By matching the model you are hoping that the adaptives are "close enough".


)

Adaptives are stored in ROM on newer Marvell drives. Older
WDC chipsets do not store adaptives in ROM.

[jono-ats]

Adaptives are stored in ROM on newer Marvell drives. Older
WDC chipsets do not store adaptives in ROM.

True, except that there may be variation in the head maps stored in ROM on older drives.

[jono-ats]

Adaptives are stored in ROM on newer Marvell drives. Older
WDC chipsets do not store adaptives in ROM.

True, except that there may be variation in the head maps stored in ROM on older drives.

[Russwinters]

I

By matching the model you are hoping that the adaptives are "close enough".


)

Adaptives are stored in ROM on newer Marvell drives. Older
WDC chipsets do not store adaptives in ROM.

I apologize I was misusing the word adaptive.

There is information stored in a ROM chip on older PCB with WDC chipsets (44pin)

I am not 100% versed in what information is contained, obviously head map, but there must be something that can differ from drive to drive.

I have had specific cases where for example, a WD400BB-53CLB0 will have PCB damage.

I acquire an identical drive, WD400BB-53CLB0 with same PCB number.

this does not work. Yes, it could be head/preamp damage, but it turns out not to be.

Transferring the 44pin ROM allowed the drive to come back to life!

Head-map was identical.

[Alexii]

The moral of the story - Kevin, move the eeprom from patient board to ur donor board =)