Hi guys,

I recently swapped out a western digital PCB, and I did also move over the old U12 chip to the new PCB. I made sure the Drive model, as well as the pcb model were exactly the same.

After the swap, I get the exact same problem -- drive does not show any indication of power whatsoever (no spinning, nothing).

Wondering if it could be something else at this point. Thanks

A shorted preamp could result in a no-spin symptom. What happens if you place a business card between the PCB and the HDA?

_________________
A backup a day keeps DR away.

Sorry, my terminology when it comes to boards isn't that great. What is the HDA? Where it makes a connection between the pcb and the drive?

The board makes contact with the drive at the motor terminals and at the 20-pin HDA connector.

HDA = Head/Disc Assembly

See http://hddscan.com/doc/HDD_from_inside.html

_________________
A backup a day keeps DR away.

Thank you.

So the HDA we're talking about here is the top part labeled as "head contacts" in the picture?

One more question: What would happen if i took the U12 chip from the DONOR pcb and used it to try and recover data?

I put a business card between the "heads contact" and plugged it in. Does the same thing =/

Is this your board?
http://ep.yimg.com/ca/I/yhst-14437584971410_2271_857360

... and is your query related to your earlier thread?
viewtopic.php?t=26730

Can you show us photos of the original board and the donor?

Does the drive make any sound at all, however faint?

Have you measured the resistances of the motor terminals?

_________________
A backup a day keeps DR away.

Hi fzabkar,

Thanks for replying so quickly.

That does indeed look like my board. It is related to the previous thread but it's a different model # than the one I had in my opening post.

I'll try and get some photos of it tomorrow.

it does not sound like the drive is making any sound at all. I keep holding it to feel if theres any vibration and nothing.

I have not measured the resistance. I'm a bit of a newbie when it comes to those things. Do I just set my multimeter to 200K, and, if so, which do I use for positive/negative? Thanks for putting up with this

Alrighty, so here are all the photos. I have the front/back of drive, as well as front/back of the PCB boards. The PCB board on the right (more green) is the DONOR board with the transferred U12 chip. Thanks for all your help

http://i.imgur.com/FrVb3W8.jpg

http://i.imgur.com/RHYCtUi.jpg

http://i.imgur.com/se1DKoU.jpg

http://i.imgur.com/SBz6Pwt.jpg

Up by the sata connector you'll see some missing solders, this is my fault for heating up the board on a surface that the plasic melted onto the board. I did do it right the first time, though, and still got no drive power when plugged in. This only happened when I tried to resolder it a second time to be sure.

I can't see the markings on U12 on your donor PCB. I wanted to make sure you hadn't installed it backwards.

Anyway, I would start by measuring the voltages at L2, L1, U21, U20, D2 and U7 on your patient PCB. These will be associated with the onboard power supplies.

_________________
A backup a day keeps DR away.

Thanks. I'll do that.

Also, I believe that is the correct orientatoin. I tried to keep it facing correctly when desoldering. I've tried flipping it anyway, and no luck.

That may have killed it. :-(

_________________
A backup a day keeps DR away.

Yikes, hope not. I did try it with the original orientation first and no power. There's a tiny indented dot in the chip, and I compared it with similar boards and seems to be in the right corner

If it survived, I'd buy a lottery ticket.

_________________
A backup a day keeps DR away.

Well, thanks for the help anyway

the orientation of u12 is correct in pic http://i.imgur.com/se1DKoU.jpg
you can see the square cutout marking on the screen of the pcb marking on the right side of the chip outline, and the dot marking pin 1 in upper left of the chip on the donor board.

I fear for the state of the components after this work..

Thanks. That was the original orientation and it didn't work like that unfortunately. Is there a guide on testing the electrical components of the pcb?

Voltage or Ohms? When I set it to 2 volts (or 20) and measure L1 and L2, I don't get any reading at all (I've switched around the leads too)

Measure the voltages between ground and each of the components (with the PCB powered up).

BTW, I believe this will only be a post mortem exercise.

_________________
A backup a day keeps DR away.