PCB schematic

[Jar]

Any idea where I can get a PCB schematic for a WD800BB, or just some diode points to test? PCB is dead.

PCB: 2061-701292-000 AP
Rev A

[lcoughey]

Why bother? Just find a matching donor PCB, swap the U12 and you have a working PCB.

[Jar]

Curiosity mostly. I don't particularly need this HD to work, but would like to know what went wrong on it, or fix it in case I need it for a hot swap in the future.

[jono-ats]

This schematic is proprietary intellectual property that us unavailable in the public domain. In other words, ya ain't gonna find one.

[Jar]

Any known points that I can test for diodes/fuses?

[fzabkar]

Here is a board, including U12 transfer and postage, for US$70:
http://www.hdd-parts.com/20091021.html

The TVS diodes are D6 and D5, and the zero-ohm resistors are R82 and R81.

Q8 is the +3.3V pass transistor. Its voltages will be +3.9V, +5.0V, and +3.3V (BCE, left to right).

You should find +5V and -5V at the pin 1 end of the preamp connector (J1). These are the preamp's supply voltages.

You should also test the voltages at D4, D3, L1, and L2 near the SMOOTH motor controller. These are the two switchmode DC-DC converters. One supplies the Vcore voltage for the MCU (+1.35V ?), and the other supplies the -5V for the preamp.

[Jar]

Thanks fzabkar. I could not locate some of the components that you have mentioned. I am pretty sure this board does not have D5, D6, R82, or R81.

I guess the ROM could have been corrupted during the process and I will end up testing that as well.

Attachments

[fzabkar]

You appear to have an earlier version.

BTW, Q6 is a P-Channel MOSFET, as is the similar device nearby. You should also test R120 and R050. These are involved in current sensing/limiting.

The positive DC-DC converter has a step-down buck topology, whereas the negative converter appears to be the inverting step-down type:
http://www.maxim-ic.com/images/appnotes ... 7Fig02.gif

The PWM control signals are provided by the SMOOTH motor controller.

You could also test the supply pins of the flash memory (U12) and SDRAM.

My HDD IC database may be of some help:
http://www.users.on.net/~fzabkar/HDD/HDD_ICs.txt
http://www.users.on.net/~fzabkar/HDD/TVS_diodes.txt

[sachin varghese]

ineed help

HTS545050A7E380 not detecting ican hear the spinning of disk