2 iBook Clamshell logic boards that won't spin up hard drives. What gives?

[3lectr1cPPC]

This one requires a bit of background - I originally posted a thread detailing this issue back around April or May of last year, but then the thread and my account got wiped out completely with last year's crash. I never got a good answer last time, and I'm hoping that I can get to the bottom of this problem this time around.

Back to 2018 - I just got my Clamshell lot in from eBay, my first real vintage mac purchase. I had gotten a free eMac earlier on, but that was it. The lot contained a working Tangerine, and a metric ton of Blueberry parts. I had 2 logic boards. One worked fine, and I was able to assemble a full working unit with it and other pieces, but the other had a really strange issue. It turned on and would boot fine from CD-ROM, but it wouldn't seem to power any hard drive I installed, it simply wouldn't spin up no matter what I did. At the time I just assumed that something died. After all, stuff like that happens sometimes.

Then it happened again!

Fast forward to around April 2021, I have my Tangerine apart to upgrade the hard drive. I'd taken apart these enough at this point that it was no challenge whatsoever. I got the drive installed and the computer reassembled. I tried to start it, but I got no chime and no power. I unplugged it and that's when I smelled that oh-so-well known smell of "electronic smoke", aka the smell a computer board lets out when something just blew. I took the whole thing apart again, but I couldn't find the source of the smell. Nothing looked blown. I did another test at this point and it started up, but it now had the same issue that the other blueberry board did. No hard drive power.

One is just bad luck, but two? So, what's going on here. Best case scenario, something shorted and blew a fuse. But where is that fuse? I'm no expert in what SMD fuses look like, but I can't seem to find any. When I got the 2nd board out of the bottom plastic case, the bad smell came more strongly from the back of the board, near where the hard drive is mounted.

Here's another thing I noticed:

One of the boards is missing a tantalum cap, clearly having been ripped off! If the board missing it had the issue and the one with it didn't, I've found my issue. But both boards have the issue, so I'm inclined to believe that the cap is not the cause of the problem, at least I assume not. It's also not all that close to the hard drive area of the board. The cap also isn't shorted to ground on the board where it is present.

That pretty much exhausts my troubleshooting abilities. Does anyone else have any ideas? My Blueberry clamshell's board has been getting rather flaky lately, and it would be nice to get these 2 back into service again. Does anyone know what pins of the IDE connector carry the power for the drive motor?

3lectr1c

 

[3lectr1cPPC]

Well, good news. I think I may have solved the issue on one of the boards. Maybe. We'll see. I found TWO RIPPED TRACES where something scratched the board!

I couldn’t get any closer thanks to my iPhone not focusing up that close, but I checked and they don’t have continuity. I’ll run 2 bodge wires and see if that fixes this board. This is the same board with the ripped capacitor. I’m not sure whether this is the original board with the issue or the tangerine board as I’ve gotten them mixed up…

 

[Juror22]

Are you using the same adapter for all these clamshells? If so, have you tested the output of it/them lately? I've had a couple of them go bad in the past few years, same as any other power supplies - due to bad caps that needed replacing.

 

[3lectr1cPPC]

I use the same yoyo charger on every one of my laptops with that plug and they all have no issues, it's just these 2 boards that won't spin up the drives. Unfortunately my blueberry's main board is also having problems now. It has had an issue for ages where if I shut it down and try to start it up again it will chime and spin up the drive but not output any video or boot. It also doesn't recognize its soldered in RAM, and now sometimes when I try to start it the hard drive will spin up and down like mad and it will give me the question mark folder. The last one may be the drive on its way out but the rest are pretty annoying, especially only being able to start it on a cold boot.

Nonetheless, how do you test the voltage on that style of plug? I tried negative on the outer shield and positive on the inside jack but it doesn't give me a reading. My multimeter has annoyingly short and stumpy probes as well.

 

[3lectr1cPPC]

Nope. Patched the traces and it gave the same result. No disk power

 

[Juror22]

how do you test the voltage on that style of plug?

Apparently, the short answer is, you can't. For the original adapters, it seems that if they are working normally you will get the light show (the green light/orange light indicators) and if its not it stops. I have enough of these (parts iBooks) kicking around that I think I could rig up a tester, using a scavenged socket and maybe some kind of a resister load to trick the internal chip?
What I've read from the Apple boards is that
1) The outer barrel is basically only a guide and does little else.
2) In one instance, the internal plug had been 'fixed' by replacing it with a 2.5mm phono plug. So, it comes down to trusting the idiot lights or rigging up something to get at the inner plug (possibly while it is under load or plugged in) without shorting the whole deal.

The reason that I found this post again (sorry that I did not see that it needed a response sooner) was that I was looking into checking the adapter for my snow iBook - basically the same adapter, but without the lights. I have one iBook that is coming up and the other is not, and the one that is up, I would like to keep that way for a few hours to see if the battery (not the original) will still hold a charge. I have it on an aftermarket adapter and the original (I think) was not working.

Did you ever get your drive issue sorted?

 

[3lectr1cPPC]

Thanks for the info on PSU testing. Both my yo-yo adapters are still good for now luckily…
And no I did not ever get that issue fixed. One board is a freak occurrence, but 2? Hopefully this won’t end up happening to more of them.