Question Hard Drive PCB Test

[oceanair1]

I did the old wrong power supply cable goof and I think it's only the pcb that is now wrong with my hard drive.

Can anyone please point out the fuse and diode locations on a WD 800039-001 PCB?

I know how to work my multimeter but can't figure out which the fuses are.

 

[hotaru.hino]

You could start by marking off anything with a C or an R, since those aren't what you're looking for.

However, I doubt this thing has a fuse, as this isn't a device that can suck up excessive amounts of power. And diodes are only useful for reverse polarity protection... which isn't expected so I doubt it has one of those too.

 

[oceanair1]

Thanks for your reply. I'll check it out.

I had read somewhere that in these cases sometimes the diodes get shorted and could get removed.

I'll probably just find a replacement board and swap the rom.

Have a nice weekend!

 

[fzabkar]

D3 and D4 are the 5V and 12V TVS diodes, respectively. R67 and R64 are the corresponding zero-ohm resistors. These resistors behave like fuses and typically go open circuit when a diode is shorted by an overvoltage.

TVS diode FAQ:
http://www.hddoracle.com/viewtopic.php?f=100&t=86

Similar setup:
http://www.hddoracle.com/download/file.php?id=1084&mode=view

 

[fzabkar]

You could start by marking off anything with a C or an R, since those aren't what you're looking for.

However, I doubt this thing has a fuse, as this isn't a device that can suck up excessive amounts of power. And diodes are only useful for reverse polarity protection... which isn't expected so I doubt it has one of those too.

WD uses zero-ohm links (R64 and R67) in series with the TVS diodes. These TVS diodes provide overvoltage protection. Read my FAQ.

Most modern HDD and SSD PCBs have smt fuses in series with each supply. Alternatively, they will have electronic fuses.

Protection devices used in HDDs and SSDs:
http://www.hddoracle.com/viewtopic.php?f=100&t=1615

 

[oceanair1]

D3 and D4 are the 5V and 12V TVS diodes, respectively. R67 and R64 are the corresponding zero-ohm resistors. These resistors behave like fuses and typically go open circuit when a diode is shorted by an overvoltage.

TVS diode FAQ:
http://www.hddoracle.com/viewtopic.php?f=100&t=86

Similar setup:
http://www.hddoracle.com/download/file.php?id=1084&mode=view

Thank you fzabkar

Just what I needed

Have a nice weekend

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