Macintosh Portable M5120 Repairs

I just got a Macintosh Portable in the mail today, and I was told it boots to a floppy disk screen. Turns out, that wasn't true. It doesn't even boot at all. The startup is very erratic, sometimes doing one thing and other times doing another. It will sometimes:

- Boot to the mouse cursor, but then the screen flashes and glitches.

- Boot to the zebra stripes, but become caught in an endless loop of booting.

- Boot to the zebra stripes, but then display a Sad Mac with error code 00000012 0000CD36.

A little while after that happens, the screen begins to flash and glitch while the floppy disk and hard disk make this combination of a click and a buzz a few times a second. No startup or death chimes are heard, either.

Sometimes, I'll also get random Sad Mac error codes, but sometimes it will be 00000012 0000CD36.

If anyone can help me, that would be greatly appreciated.

I can safely assume that it is due to the battery because it has the original battery and that it will need to be replaced, but I hope I don't have to recap anything.

Many thanks in advance!

someone apparently hasnt read just about EVERY other portable thread here.... 

IT NEEDS CAPS. CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.

Lets try again shall we... 

CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.CAPS.

Sorry. Maybe hopefully I get my point across. Oh BTW you DO NEED a good battery as well. the portable is not designed and WILL NOT properly run without a battery. 

Now that those 2 things are out of the way, any questions? 

everyone who comes here asks the same exact question.  

can we get a sticky at the top of every header that says replace capacitors?

I have indeed read the other Portable threads on here, and I understand that new caps may be needed, but I hoped that the caps aren't dying or dead because I'm not sure if I can do the task myself. But it appears that the caps may be the issue. Reason I posted this was because this was a unique and strange bootup situation that I had never seen anyone talk about or mention online, even on these forums. I tried to look up on if any situation similar to mine happened, but I found nothing after extensive research. That's why I started a new thread. But getting to the point, I'll see about a recapping service, but first, I'm going to try replacing the battery. The Portable came with its original battery (which indeed is old), so I can guarantee that the battery is completely wasted. So I'll get a new sealed lead acid battery and see if that works, and according to my research, the Sad Mac error code I'm seeing the most involves the Power Manager. If that doesn't work, then I'll see to recapping. Why am I doing the battery first? Because compared to the recapping services that I've seen, the batteries are rather inexpensive. So you could say I'm working my way up. I appreciate the advice regardless, and I'll see what I can do tomorrow. Thanks!

By the way, I'm sorry if this sounds like something you've all heard before, but I did a LOT of browsing today on this forum trying to find an answer to this unusual and rare event and found nothing. But I hope you all can help me along and bring this beautiful acquisition back to life. Thanks again!

its not rare but if you look at any boot issue on any old mac you will see caps caps caps.  its standard now.

I bought one a few years back and here is what I learned:

1) DO NOT start it with an incorrect adapter and a dead battery.

2) DO have the mother board re-capped.

3) Irreparable damage will be done to the system if you fail to follow items 1 or 2.

Stop trying to start it with the bad battery.  There is no option to replacing the caps on your new acquisition, just how you will accomplish the task.  Since you don't have the skill to remove the old caps and resolder in new ones, I would engage someone (uniserver does this for a lot of us here) to perform the recap as soon as possible.  I have two of the these (one a backlit and the other not)  I killed one of the motherboards by not following the rules above and don't want this to happen to someone else.  It was an expensive lesson to learn.

Congrats on getting one of these and best of luck in getting it fixed up.  The issues should clear up after installing the new battery and caps.

I bad similar problems. I also didn't want to give up at first. Until I realized I could damage my precious system. Uniserver recapped my motherboard and I bought a new battery. Uniserver also managed to repair the board after recapping because more was wrong. So spend some money and save your Portable!!!

I have yet to do anything, but I'm getting very different symptoms now. I no longer get the glitching screen, I get the mouse cursor and I'm able to move it around, but the hard disk or floppy disk is making these weird noises and the system is not booting. But the severity of the boot sequence appears to have decreased. Is this good or bad?

Again, refer back to previous posts please. 

Eventually youll blow the motherboard up and you wont be able to fix it. Trust me on this. 

If you can recap it then hopefully you can get it working again. Otherwise, I would contact Uniserver or some other folks and see if you can get a recap job done. 

It NEEDS done. period. 

OK, OK. I'll leave it alone. I'll contact the other members like Uniserver to see if a board recap can be done. It may be a while before this happens as I have other stuff planned this weekend. In the meantime, I'll leave the Portable disconnected and not touch it or even power it on until after the job is done. I'll talk to experts on this topic and see what they can do. Another thing is that there is a recapping service on eBay for $75. Which would be the better bet here, eBay or guys on the forum? Any help or advice on this recapping job will be greatly appreciated!

If the recap service on eBay is from Uniwho or similar, that is Uniserver. He comes highly recommended. Good luck!

The recap service is by "morestuffuniwho," which I can safely guess is Uniserver. Looks like I know who to turn to! Thank you all!

Once you get it recapped and the battery rebuilt, its a fun machine! take care of it!

Got my new battery today, and I've actually managed to identify the source of the main problem - the hard disk! If I disconnect it from the board, the computer will give me the blinking floppy disk icon without any problems. The disk images I used for the floppies might be damaged, though: They will give me a system error after giving me the desktop and abruptly going to sleep or not boot at all, which is strange. But still, I'm one step closer to fixing this thing! Once I get the spade terminals and wires all ready, I'll be able to properly connect my battery to the computer. However, I may have to replace the hard disk because it doesn't work properly, but I'll see to that after the battery is installed because it may work correctly if the battery is put in. Thank you all for guiding me along on this fun adventure!

Gave it a little time with the battery, and guess what - the hard disk works again!

Sounds like good progress in the right direction! However... 

Did you get a chance to recap it yet? Recapped machines fire up instantly usually. No issues. 

Sorry, but no, I have not yet had a chance to recap the machine between then and now.

BUT...it does boot up right away and it boots very quickly, even if I haven't recapped it yet. No Sad Macs on startup anymore. It will even boot from an external SCSI! However, there might be an issue with the software or the battery might need some time to charge, because I get a "no reserve power remains" warning after it boots. Between 1 to 15 seconds or after it loads something, it will go to sleep. When I wake it up, it will do one of two things: It will repeat the previous stated action or it will give me a bomb error saying either "address error" or "illegal instruction". The same bombs are also likely during bootup, occuring during the "Welcome to Macintosh" message or while the desktop begins loading. The illegal instruction bomb is the one that appears the most. The sound is still very quiet from the speaker, but it will work if I plug in headphones. But if I leave a bomb error on the screen for a while with headphones plugged in, it will begin making high-pitched wails, which stop once I reboot. Also, if I unplug the computer to let it run on the new battery, it will say the battery is charging and without any juice in it if I open the Battery DA, but that's not true. Maybe I should get the proper connectors at some point. So with that said, I will look into recapping, but there are two concerns: 1. It's expensive and shipping may be a hassle. 2. It's risky because if I disassemble the machine to get to the logic board, I'm worried that I'll lose all the progress I've made in trying to repair this beautiful device. And yes, I understand that recapping IS a priority if you're trying to repair a 27-year old Macintosh Portable, but it's possible that the caps might not be the issue. But you know what they say: Better to be safe than sorry. Thanks, techknight!