Macintosh Portable Hard Drive (Conner 3045 board swap)

[uniserver]

Thanks to bunsen and thanks to mcdermd.

I didn't even realize this (until Mcdermd mentioned it) but i had the identical hard drive in my Macintosh Classic.

The HD in the Portable was bad.

I removed the boards and swapped drives from the working one in the classic.

However, dammit the swapped HD started doing the same thing as the old one!!!

it would try try try, then it would finally spin up, and it would basically do nothing.

Checking over the Low Power HD PCB I noticed there was a 20v 10uf Tantalum cap that was black already but it looked sorta cooked.

So i removed it, and changed it for a good one.

also right near the DATA/Power connector, there were 2 more caps, 20v 6.8uf. i removed those too and replaced them with some much bigger 16v 47uf tantalum caps,

Anyways the hard drive now hits and spins up great, INIT's and BOOTS!

My only problem is if i disconnect the charger, the HD will not run off battery.

i also re-capped the whole board. so i know the caps are fresh.

Sometimes if I unplug the charger after the hd is already fully booted, it will stay running for about 10 seconds, but then power down, then it try's to power back up a few times and gives up. The battery meter says there is like 95% battery left.

Anything I am forgetting ? If you want pictures of the HD PCB let me know and i can post them on here.

 

[uniserver]

ok i decided to leave the power plug in today, while i'm at work, with it in sleep mode.

Maybe the battery can use a trickle charge?

Still trying to figure out why the hard drive doesn't want to run with out it being plugged in.

It will boot off floppy and run just fine of battery.

I am just going to assume the battery is low, even though it says 95% charged.

I'm starting to really like the portable, Its really growing on me. I think its the screen, i love the screen!

I changed out the Mouse ball Contact Rubbers from a broken powerbook I had laying around.

the mouse is now smooth, works good.

Was playing some sim city on this thing last night, and when you use the arrow keys to scroll around, the refresh is fast! its impressive. Way faster then the Macintosh Classic! I guess that extra 8mhz helps!

 

[James1095]

Measure the voltage at the drive and at the battery as you disconnect the charger. It's possible you have one or more weak cells in the battery causing the voltage to sag rapidly as soon as the charger is disconnected. The battery meter likely won't know how to deal with this, as it expects a battery in reasonably good condition. I don't think battery packs in the era of the Portable had much if any build in intelligence to assess the health of the cells the way modern ones do.