Help with disconnecting TVS from Seagate Barracuda 7200.11

[gadgetsolo]

Following up on my previous post: http://forum.hddguru.com/seagate-barracuda-7200-think-its-electrical-failure-t13358.html

Here are details of the H/D

-Seagate Barracuda 7200.11 (+5V 0.72A/+12V 0.52A)
-1500 Gbytes
S/N: 9VS1GSKP
ST31500341AS
P/N: 9JU138-302
Firmware: CC1H
Data code: 09373
Site Code: TK
Product of Thailand

I would like to try to fix the blown TVS on my HD. Here are pictures of my PCB:

full PCB-->

Zoomed view of PCB--->


Can someone please guide me on how to remove the TVS? Specifically:

1) Which part is the TVS? From previous posts, I suspect it is the area I highlighted in red here:


2) Based again on previous posts regarding TVS, I am assuming there are 2 TVS chips. Assuming I have access to a multi-meter and then measure the resistance across the TVS, what are the normal values?
3) Once I identify the "bad" TVS, what is the correct way to remove it?

btw, I am not too concerned about replacing the TVS so that the H/D is fully protected , I just want to recover the data.

Thanks!

[fzabkar]

You have correctly identified the two TVS diodes. The one marked "LEM" is the 12V diode, the other is 5V.

Set your multimeter on the 200 ohms range. If a diode measures close to zero ohms, then it is shorted.

Remove it by desoldering it, or snip its pins close to the body with side cutters.

Good luck.

[craig6928]

easy job to do make sure you put the tvs diodes the right way.

get some flux dip your solder tip in and use some

Desoldering Braid Wick

dont keep the iron on long as you can lift the pads on the board

normal if they have blown you can see this right away.
as they have taken the force of the power

possible might had damaged others on the board

[gadgetsolo]

Thank your fzabkar & craig6928 for the help!

Another quick noob question: in reference to

or snip its pins close to the body with side cutters

what type of tool should I use? specific tool name and specifications would be great, i.e. something I can ask for directly at my local hardware shop

thanks

[fzabkar]

I use this:
http://myrobotkit.com/images/sidecutters.jpg

[craig6928]

do you not have a low watt soldering iron ???????

i would not use cutters as you can do more damage

[fzabkar]

do you not have a low watt soldering iron ???????

i would not use cutters as you can do more damage

IME, if the pads are intact, then you have less chance of damaging your board by using flush cutters. Just hold down the diode to stop it from flying into your face.

When repairing multilayer boards, I used to make it a policy never to attempt to remove a component in one piece. Wherever possible, I would snip each pin at the body of the IC, remove the body, apply solder to the remaining pins, and then remove them one by one.