PowerBook 100 Recap woes

[perez6991]

I recently got my hands on a PB 100 with the common BSOD, which meant it needed to be recapped completely. Fast forward to today and I was about done with the recap, only needing about 5 on the LB and the ones behind the display. Out of my curiosity I decided to partially assemble it and attempt to power it on to no avail the first 15-20 attempts (only a light hiss from the speaker ever so often). Then suddenly the PB springs to life, sorta. The screen had lines everywhere and the death chime would repeatedly sound but getting faster within a short period of time. About a few seconds. Pressing the reset button on the side got me a bit farther to the floppy disk screen then almost immediately to a black screen followed by static from the speaker. I'll probably record a video of it doing its thing, explaining in text is rather troublesome.

So here's what I think. Either.. I need to finish recapping the whole PB or the power supply is no longer supplying the required voltage or amps to keep the PB running.

Any help is greatly appreciated.

PS. When I first got the PowerBook it would power on with a normal chime and obviously the BSOD. The hard drive would spin up but the read head gets stuck.

 

[Byrd]

I feel your pain perez, having recapped three PB100s in quick succession all with similar results - prior to the recap some would chime, HD spins up, lines on screen.  Recapping mostly resulted in hissing/crackling/broken chime sounds.  I used a known good PB100 LCD and all caps were double checked, and replaced (I thought I had bad new caps).

... they now sit alone, unloved.  Future efforts will be to fully wash/dishwash the board and start again, but they're incredibly fragile things.

JB

 

[bibilit]

The Powerbook 100 needs all caps removed and replaced on the Logic Board, and that's mean a lot of them.

 http://www.maccaps.com/MacCaps/Capacitor_Reference/Entries/1991/10/21_PowerBook_100.html

The first one i made was for Galgot, and it refused to behave ok until the very last one was replaced (the one behind the daugtherboard)

You were able to see the floppy disk once,so is a good point.

Recapping mostly resulted in hissing/crackling/broken chime sounds

Happened to me a couple of times, never found the issue.

Also, the PSU will need new caps, all are within tolerance today.

 

[aplmak]

I've done so many of these.... many, many.... keep in mind the battery compartment has a switch... to tell whether the main battery is installed or not. I have had luck switching the main switch on the back I think in the downward position (battery off) and NO battery installed.. I take the door off the battery and put double sided scotch tape on both sides and put it to cover the hole.. It works and looks pretty nice! Don't stick one of the old batteries in there... They are all dead now.. and the PB does funky things with it installed with the switch in either position on the back.

And yes I second the fact that the PSU needs new caps... many of the PSU's I opened had leaky caps... sometimes they rusted the screw that holes the board down.

 

[perez6991]

Good news! I “finished” recapping the PB100 and to my surprise all those headaches vanished. Speaker cracking, death tone, erratic booting are all gone now. The fix was simply to finish recapping the entire logic board.

As for the power supply, I cracked it open and there’s no corrosion, fish smell or bulging caps. I’ll still recap it at a later date though. The only cap I didn’t replace because I miscounted how many I needed was the tiny cap on the daughter board. All is well with everything else though.

Now for my next tiny issue, the original hard drive. Is there any way to fix the actuator arm in the hard drive? It sticks to the point where it clicks but moving it manually makes the drive function. I do have a spare drive from a 520 with a dead floppy though, is it worth the hassle to fix the 100 original drive?

I also want to thank everyone for sharing their ideas on the initial troubleshooting.

 

[perez6991]

Well it seems my spare scsi drive chooched her last breath with the same symptoms as the PB100s original drive. It spins up and “initializes” fine but then a rapid ticking noise every few seconds follows. Could this be an issue with the last cap I didn’t replace on the daughter board? I ended up ordering a CF Powermonster II just in case.

 

[LOOM]

Old drives are on the end of their lifetime for several reasons, and will die eventually. Sometimes the oil around the ball bearing dry out over time, makes it harder and harder for the disk/motor to spin it up (sometimes you can use a small trick to boot it a last time by warming (with a hair dryer) the spindle so the oil/bearings flow more easily, but it's on your own risk and the disk can be worse after this so use it as a last step just to get the data out). I even got a disk to spin up a last time just by tapping on it with my finger when it tried to "start", just so I could save the data on it.

Mechanical parts will fail and need to be replaced or fixed. b:

 

[bibilit]

Fixing those drives seems to be easier than bigger counterparts, there is a trick on this forum to get them going again.

https://68kmla.org/forums/index.php?/topic/27749-powerbook-100-connor-hard-drive-repair/

I have repaired a fair amount myself, and are still working today.

 

[PB145B]

Yeah I’ve done that fix on a bunch of Conner drives and they all still work fine!

 

[LOOM]

I didn't know about that trick. Good to know!