Western Digital Cavier SE16 - fried power coupling-not chips

[natoround]

howdy all, saw some prev posts on these drives and pcb issues. I've not yet taken a look on the underside of the pcb.. .but at this stage it looks like the damage is limited to the power coupling which is fried out on a couple of the contacts on the sata power coupling. Wondering if someone can tell me the liklihood this has caused issues down the line. (ie on the chips) if not can I swap out the pcb for another?

thanks alot

[jono-ats]

1. Very high probability (i.e. almost certain) "chip damage down the line";

2. Lesser possibility of damaged preamp / head stack;

3. If preamp is OK, PCB can be swapped, but ROM must be as well;

4. If preamp is bad, time for pro or game over.

[Vulcan]

howdy all

G'day

it looks like the damage is limited to the power coupling which is fried out on a couple of the contacts on the sata power coupling

Supplying some close-up, clear photos of this drive's PCB (both sides), and especially of the damaged area, would help others to be able to give you an opinion.

Also, what's the history of this? Was the drive in a USB enclosure or directly installed in a system case? What happened between it working normally and then having the damage that you can see (but which we can't yet see )? What tests have you done so far, and with what results? Have you identified any cause (e.g. external) for the drive to become damaged in this way?

Wondering if someone can tell me the liklihood this has caused issues down the line. (ie on the chips)

That depends on what the history of this drive was (see questions above) - for example, if there was a lightning strike to the PC which caused this, then I agree completely with jono-ats that further unseen damage is likely. If you've melted the power connector, that needs a serious amount of current, but without a photo and some history of the events to give the readers here a starting point (see questions above), who knows!

As some people might say it: if you want some help, throw us a bone, please The more clear info that you give, the better the chances of you getting useful, applicable replies.

If you search the forum you'll see that another Aussie member (fzabkar) seems to have more patience than I do, to perform remote reverse-engineering through a forum, and has explained voltage measurements & resistance measurements across power rails (for example) to try to identify damaged components in other threads. You might want to read his postings to see whether you believe similar measurements are within your skills or not.

[natoround]

solid, I appreciate the help, I know it was a bit of an ask... just gotta get my hands on some screwies to dismount the pcb and then I'll post some photos.

As far as I know, knocked the power cables which were more or less hanging out the side of the case (that'll learn me for keeping a sprawling open case setup). Hdd made some funny spooling noises, smelled some smoke.

Checked out the hdd, and all I saw was 2-3 of the contacts on the drives power connector "caramelised", but couldn't see anything else. Other than that the rest of the system runs ok (obviously without that drive connected).

Appreciate the help, photos to come.

[natoround]

got me a screwdriver to check it out; as far as I can tell the only hint of damage past the power connector is very very slight tarnishing on the contacts around the chip on the bottom left of first photo.

The 2nd and 3rd show the coupling

sorry just got cam, tried my hardest for a clear set of photos, seems to show enough detail though.

[fzabkar]

The damage has affected the +5V pins and and a adjacent ground pin. Most likely the drive sustained an overvoltage on the +5V supply, in which case I would expect that the 5V TVS diode (D3) would be shorted, and resistor R67 open.

Set your multimeter ($10 at Dick Smith Electronics or Jaycar) on the 200 ohms range and measure the resistances of both components.

[Vulcan]

tried my hardest for a clear set of photos

Thanks for trying

I have a slightly different hypothesis from fzabkar so feel free to consider both, either one of them, or neither of them - your choice. He might be correct to suspect TVS, or I might be correct, or neither of us...

There's not enough detail of those pins in the photo for me to be sure - IMHO it would need some magnification and removal of shake However I am concerned that connector pin 10 is shorted to pin 9. There is certainly something very suspicious in that area of the photo IMHO, which looks like a whisker of metal.

My theory, based on what you said happened and the photos, is that you twisted the power cable while it was still attached to the drive, such that the pins 10 & 9 on the drive were shorted together (i.e. +5V to ground) by a pin on the power cable (probably pin 10), as the power cable was twisted. The plastic of the power connector itself appears damaged near pin 1, which is consistent with the possibility of lateral displacement / twisting of the power cable. I have experienced similar issues on other equipment with edge connectors, where the connector was not mated perpendicularly to the board

Therefore I'm not expecting TVS damage (no overvoltage) - but do carry out the measurements that fzabkar suggested; I could be wrong and he could be right. However if my theory is correct and there is a short on the SATA power connector itself, then the TVS may appear to be shorted when, in fact, it isn't.

Whatever the state of the TVS, that SATA power connector needs attention, or removal / replacement / bypassing, before you next apply power to that drive. There are several options for what to do at that point, depending on what exactly is wrong on closer examination, and on your soldering skills / tools availability / component availability / time availability / risk assesment

I also suggest you look at the power cable which was connected to that drive, when you knocked the cable - do you see any damage to the contacts inside the cable connector which was attached to the drive? You may need a torch & loupe etc. In any case, based on the damage to the drive's power connector, IMHO you must not use that power cable again, as it cannot be trusted.

Good luck