Western Digital WD1200BEVE not working

[craigdf]

Hi
I have got a few Western digital 120GB IDE 2.5" hard drives which do not work.
The hard drives have been overvoltage on purpose.
I have removed the PCB from one of the western digital hard drive and powered it up. 5 Volts and 3.3 Volts are present. the PCB shows no sign of damage.

Does anyone know where I can get the schematic for the following hard drive so that I can try and find out what the fault is?
Western digital WD1200BEVE - 00WZT0

Or do you know what goes wrong when the Hard disks gets over voltage.



I would like to try and fix these as I know I will be able to sell them

regards

 

[fzabkar]

Is this your board?
http://data.stuartconnections.com/object/image?p=8790&i=1

If so, is the +1.35V Vcore supply present? There is a test point at 6 o'clock on the center circle.

There appear to be three supplies, two switchmode and one linear, below the SMOOTH motor controller. I suspect that Q1 may be the pass transistor in a linear +3.3V supply, while one of L1/D1 and L2/D2 would constitute the Vcore supply. The other may be the negative supply for the preamp, assuming this supply exists.

The following datasheet has several application circuits that may help you understand the functions of a typical SMOOTH motor controller:

L7250, SMOOTH, spindle motor + VCM controller, ST Microelectronics:
http://wandrew.regruppa.ru/PCInfo/TechDoc/L7250(Smooth).pdf
http://www.datasheetcatalog.org/datasheet/SGSThomsonMicroelectronics/mXyuswx.pdf

FYI, here is my database of HDD datasheets:

http://www.users.on.net/~fzabkar/HDD/HDD_Semis_Regs.html
http://www.users.on.net/~fzabkar/HDD/HDD_Read_Channel.html
http://www.users.on.net/~fzabkar/HDD/HDD_RAM.html
http://www.users.on.net/~fzabkar/HDD/HDD_Preamp.html
http://www.users.on.net/~fzabkar/HDD/HDD_Motor_Control.html
http://www.users.on.net/~fzabkar/HDD/HDD_EEPROM_Flash.html

Hopefully my tutorial will be of some help:

Tutorial - how to locate the basic test points of an unfamiliar HDD PCB:
http://www.users.on.net/~fzabkar/HDD/Tutorial_SP0411N.html