Safely power up 128k for first time in years

[wezm]

Hi folks,

I'm the proud new owner of an M0001P.




It's been stored in its carry bag for a couple of decades. I'm aware of electrolytic capacitors leaking and Rifa caps exploding so I want to do some pre-emptive maintenance before applying power and I'm looking for recommendations on what to do. From some reading I've done it seems the 128k isn't all that susceptible to leaking electrolytics, so I suppose I could leave those if they look ok on visual inspection. The Rifas seem more likely to need attention. In particular—if I'm looking at the right thing—C36 looks like it might be cracked.



Anyway, I await your wisdom.

 

[Byrd]

Lovely 128K!

Yes I’d replace the RIFAs, most are cracked in any Mac now but eventually they will burn out. You can get the same part that looks the same in a modern equivalent. As for the rest, check for any dry solder joints especially where the yoke board connects to the AB, see if there is any corrosion on the connector pins when disconnected.

Then - plug it into a surge board and power it up with fingers crossed. There is possibility of “bit rot” in the soldered RAM hopefully that’s not you. The floppy drive will have also gummed up but that’s would be a maintenance job later on.

 

[wezm]

Excellent, thank you for the details.

plug it into a surge board

Do you mean a regular surge protected outlet (like this) or something more specialised?

 

[JC8080]

Cool machine. The floppy drive on top looks like an 800k drive, so your Mac may have been upgraded to a 512ke.

 

[wezm]

I don’t think it’s been upgraded but it is an 800k drive. It’s possible it wasn’t used with this machine and just ended up in the bag.

 

[Fred1212]

Nice

 

[Snial]

Hi folks,

I'm the proud new owner of an M0001P.

View attachment 66109
View attachment 66110

It's been stored in its carry bag for a couple of decades. I'm aware of electrolytic capacitors leaking and Rifa caps exploding so I want to do some pre-emptive maintenance before applying power and I'm looking for recommendations on what to do. From some reading I've done it seems the 128k isn't all that susceptible to leaking electrolytics, so I suppose I could leave those if they look ok on visual inspection. The Rifas seem more likely to need attention. In particular—if I'm looking at the right thing—C36 looks like it might be cracked.

Anyway, I await your wisdom.

"Sure is great to get out that bag!" Welcome to the 68kMLA!

 

[joshc]

From some reading I've done it seems the 128k isn't all that susceptible to leaking electrolytics, so I suppose I could leave those if they look ok on visual inspection. The Rifas seem more likely to need attention.

I agree. Replace the RIFAs before any power attempt and leave the electrolytics unless you come across problems.

 

[ClassicGuyPhilly]

Welcome to the forum, very nice system!

Would you mind sharing a picture of the back plate and the serial on the underside please?

The M0001P model designation is a new one to me - I'm working with many others on the forum to document all the different variations of the Compacts.

 

[cheesestraws]

Welcome to the forum! What a nice little machine. The good news is that this first couple of generations of Macs are really quite robust and chunky, and tend to last rather well.

The things that are most likely to be broken are:

• The RIFAs may go up in smoke. This smells bad and is dramatic, but isn't actually harmful to the machine. Replacing them is a good idea - make sure you replace them with equivalently safety-rated capacitors - but this is as much for the sake of your lungs as for the computer's sake.
  
  
• The RAM may have gone bad. Apple used Micron RAM chips in at least some 128ks that have a tendency to break. Replacements aren't that hard to get at this point in time, and more reliable manufacturers made compatible RAM chips. It's worth looking inside and getting some pre-emptive replacements if you've got the dodgy Micron chips, because nobody is making new RAM like this and it's going to get harder to find as time goes on.
  
  
• The floppy drive may well have gunked itself up solid, and this can usually be dealt with by cleaning.

 

[cheesestraws]

The M0001P model designation is a new one to me

the "P" suffix is "international analogue board", so ~230V not 120. You can tell it's an international AB just from the photos (aside from the fact that OP's profile says they're in Australia!) - the cluster of four purple capacitors rather than two is a giveaway here.

Yes, I've spent too long swearing at 128/512/Plus ABs, why do you ask?

 

[wezm]

Would you mind sharing a picture of the back plate and the serial on the underside please?

 

[wezm]

I agree. Replace the RIFAs before any power attempt and leave the electrolytics unless you come across problems.

I've ordered replacement RIFAs as these ones are clearly cracked.

 

[ClassicGuyPhilly]

Thanks for the pic!

 

[joshc]

I've ordered replacement RIFAs as these ones are clearly cracked.
View attachment 66157

Hope you ordered Y class. Easy to get the wrong ones and it does matter.

 

[wezm]

Hope you ordered Y class. Easy to get the wrong ones and it does matter.

Yep.

 

[bongostar777]

friend, could you share the link where you purchased the RIFA replacements please? I need to get some for my vintage MACS.

 

[LaPorta]

Did you ever figure out what it is, if it is upgraded to? Also, make sure that you don't daisy-chain those floppies together: they will not work on a Mac like that.

 

[wezm]

friend, could you share the link where you purchased the RIFA replacements please?

I got them from Console5.

Did you ever figure out what it is, if it is upgraded to?

Yes. It's an original 128K upgraded to 512K RAM and 128K ROMs.

Also, make sure that you don't daisy-chain those floppies together: they will not work on a Mac like that.

Yeah I don't have much use for the floppy drives and haven't tried them. I don't have any compatible disks and have a FloppyEmu running in HD20 mode with a 2Gb image to run the system off.

 

[LaPorta]

If you ever decide you don't need the drives, I am always looking for them.