Apple Newton MessagePad MP110 restoration

I won my Apple Newton MessagePad MP110 on eBay towards the end of June 2018. I don’t remember much from the description other than it was listed as working when connected to the mains. When I received it, it had an official Apple rechargeable battery fitted. Unfortunately this had leaked its guts all over the battery compartment 😅.

It came with a slip case, the larger wallet case that it clips into, the introductory VHS tape and most of the original documentation. It also had three floppy discs from the previous owner with it, one containing the Newton Connection software for Mac. I haven’t properly looked at what the others contain, but assume they are apps for the Newton. I will detail my findings when I give them a look in a future post.

I didn’t do much with the Newton at the time other than have a quick but not very thorough cleaning of the worst of the battery leakage and disposing of that battery pack. One thing I should have noticed at the time was that the sound was not functioning.

Fast forward to the present day, and I stumbled across this video while browsing the 68kMLA forums.

After watching this I immediately recalled the experience of recapping my Sega Game Gears and realised I should have expected something like this to be an issue when I didn’t hear the sound on receiving the unit. I was also curious if mine had deteriorated further so that the screen would be having issues too. Turns out it was, so it was time to find some new capacitors!

I already had some through hole 100uf 16v capacitors and ordered a pack of 3.3uf 50v capacitors. I won’t go into detail on the cap replacement as the above video does an excellent job of explaining the procedure. I will however post some pictures below that I took while working on mine. While it was apart, I also took the opportunity to clean up any of the remaining battery leakage that I didn’t manage the last time I worked on it.

You’ll notice that the original caps were of a lower voltage than the new ones I put on. As long as the capacitance is the same, the voltage just needs to be at least the same as the original value.

After reassembly the Newton fired right up with a chime and the screen working as expected 😀

Everything seemed to be well, or was it?

Since receiving this Newton, I had never managed to get it to run off battery power using the included 4 AAA holder. After measuring voltages with my multimeter, I discovered that with the battery pack inserted I was only reading ~2V (I’d expect at least 6V) from the battery springs at the points on the logic board. I then noticed the tip of the top battery spring still had some corrosion on it. A quick use of one of the grinding tools attached to my Dremel and the spring was as good as new. On popping the battery pack back in, I had one happy Newton working on battery power for the first time since I’d owned it!

Overall the restoration was very successful and I’ve had a great time showing it off and experimenting with it. I’m now looking forward to trying to load some software onto it when I have one of my 68K Macs up and running next, as I only have the original proprietary Mac serial cable for it.