macintosh portable issue

[techknight]

Ill be honest, Ive never owned a portable before until recently.

I finally got around to recapping it. Recapped it, now trying to figure out this weird issue.

Plug it in with a 2amp cord. (no battery), it does the click-click. Hit a key on the keyboard, screen comes on to a zebrastripe/jailbar pattern, no chime and it shuts off. Wont power up again until i hard-cycle the power. I unplugged everything, disk drive, HDD, all of it to make sure its not a power issue. Removed the RAM card and modem as well. no dice. I removed a white jumper that was on the motherboard, and thats how I got the zebra stripes to be more pronounced. If i leave the jumper in, I cant see the zebra stripes unless I am looking at it from an extreme angle. (screen too light). No chime.

any ideas?

[techknight]

Figured it out. These things HAVE to be assisted by a battery.

Even with a 7.5v 2amp, my 5V internal logic rail with nothing connected to the logic board, was falling to 4.2v when powered on. it would chime.

Soon as i would connect an HDD, or the screen, it fell to 3.4v and did strange erratic things.

6V assisted on the battery connection, it fired right up. So, I tried the 9V method on the battery terminals alone, with the battery cover removed, it works too, but it draws around 1.80 amps idle. components start getting hotter too because of the increase in B+ voltage.

[Trash80toHP_Mini]

How many volts is that dratted battery anyway? I found some exit light backup batteries that might do as an external source for a BootBooster, if not an inefficient (wrong kind of duty cycle I would think) external battery pack.

I've also always wondered if the right lump-on-a-rope, with the lead fitted to a fake battery/contact block might work like the proverbial charm. If the lump portion was the attached to the same surge connector/switch as the AC adapter for simultaneous switching, might the Luggable never notice the difference?

[techknight]

its a 6V lead acid. I dont feel like rebuilding the original battery, because I dont know if I am going to use it enough to justify that. I might pull it out of the bag once in awhile and play with it, but thats about it.

I think the original HDD is bad too. it spins up and clicks once, thats it, it doesnt perform a seek test.

[Trash80toHP_Mini]

I posted a pinout to adapt a standard SCSI Drive, preferably laptop if available, to the connector on the Portable somewhere in the Portable related threads. It was an adaptation worked right out of specs in GttMFH2e.

There's an interesting notion for a LinksThread to sticky, ALL the Macintosh Portable links to threads from the current forums and those back in the Archives!

But I'm too lazy . . . aside from taking on waaaay too many LinksProjects™ already . . . volunteers?

[techknight]

it fired up. I let it sit for awhile on, and after a minute or so the HDD picked up and started booting into system 6.

[Trash80toHP_Mini]

[bibilit]

started booting into system 6.

Happy end

[FlyingToaster]

I almost had one a few years ago but let it go because I was too cheap. I'd give a few of my compacts to have one

[mcdermd]

And to think, I literally threw one in the dumpster six years ago. At least I kept the other one. They cost me $20 for the pair in '04 or so.

[techknight]

still need to finish my circuit mod so itll run entirely off of AC adapter. the bigger amperage AC adapter trick dont work on the mac portable backlit like mine.

[uniserver]

can you post some pictures, i really like the macintosh portable! Especially the back lit version.

[Mk.558]

And to think, I literally threw one in the dumpster six years ago. At least I kept the other one. They cost me $20 for the pair in '04 or so.

For $20 today, they'd fly off like birds in a flock.

Is it snappy under 6.0.8L?

I noticed that you can position the numeric keypad to the left of the keyboard, ostensibly for left handed use. Except the keypad pattern isn't inverted properly.

Ooops.

[techknight]

Ya I can, once I get this bad boy finished up I will post pics, and do a youtube video of course, as I always do.

[mcdermd]

I noticed that you can position the numeric keypad to the left of the keyboard, ostensibly for left handed use.

Yeah, I took a few pictures that way. You can swap the keyboard, trackball and keypad into any configuration. The case is screw-less so you can even do it without any tools. System 6.0.8 with 16 MHz and 2 MB RAM is snappy like you would expect but I think it's always more impressive how quickly it's available from "sleep". Instant-on fast.

[techknight]

Yea, i noticed that. it is snappy.

System 6 is probably a good choice for that machine. Maybe system 7.0.1 as a max OS, I coudlnt picture myself running System 7.5.3 because it would be like running vista on 1GB of RAM on a pentium 4 2.0.