This is a great piece of writing and information. Extremely useful to users like me who have an old, old T-100 that was bought used eons ago in late 1980's so my wife could take notes in the library for her Masters' Thesis.
Bradley Kuss ---------- Forwarded message ---------- From: "Joshua O'Keefe" <maj...@nachomountain.com> To: Model 100 Discussion <m100@lists.bitchin100.com> Cc: Bcc: Date: Sun, 15 Mar 2020 19:42:52 -0700 Subject: [M100] Routine maintenance report This is probably old hat to many list members for whom routine maintenance is... routine. But for those of us who are new, maybe it will be useful. I'm happy to report that I had great success on my first internal maintenance of the Model 102. I set out with two goals: replace the battery with a NiMh cell, and buff out some of the minor scratches in the screen cover. Both procedures went well. Though I did it second, first I report on the battery replacement: I had opened the T102 a few times previously to get a closer look at the keyboard situation and to repair the space bar. However, I wasn't at that time bold enough to get down into the guts of the computer beyond exploring the fact that the display and keyboard were separate boards. This time I set out a workspace, removed the top cover (and buffed it as I describe later), set it aside, and explored how to get to the main board. The display and keyboard are connected to the main board by somewhat stiff ribbon cables. I didn't see an obvious way to disconnect them that wasn't simply yanking on things. So I didn't. Instead I set out a soft surface and flipped the display and keyboard off to the right. Under those is a black plastic cover, which is loose. That could simply be moved out of the way, although the display cable is threaded through it, so there's a bit of a topologu puzzle to work out how to do that carefully. Under the cover is the "underside" of the main board. The two largest screws, one to the right side of the board and one to the left, hold the board in place. Those remove easily. The board itself is tucked under some clips at the front end and should be slid out from under them. At that point the lower case could be moved out of the way. With access to both sides of the main board, it's pretty trivial to see where the old battery is. Polarities are marked in silkscreen on the component side. The battery I received from arcadeshopper (at a very reasonable price) was not marked, but it was easy to put a meter to it and figure out which end was which. On the underside of the board I found there was a long green wire that runs within a millimeter of one of the battery through-holes. This wire was epoxied in place nearby so there simply wasnt room to bend it out of the way. I had to crack the epoxy blob to move the wire. That done, I was able to desolder the battery with relatively little effort. I've never used a desoldering tool -- I was educated only with the use of braid -- but I had one and wanted to try it out. Especially since my braid wasn't doing much beyond soaking up flux, for some reason. Once the battery was out, I used the solder sucker to clean out the through-holes as much as possible. One came clean, but the other didn't quite clear up. This is no reflection on the engineering of the 102, but on my desoldering skills. Still, one clean hole was enough to push the new battery into place and hold it so I could solder one terminal down. Once in place I could heat the remaining through-hole's obstructing solder and push the second battery terminal through. At that point I could apply a proper solder joint. I didn't need a third hand rig or a helper person for any of the procedure. Standing the board on end to hold the battery in one hand and the soldering iron in the other was the only part of the procedure that could have benefited from it, and really not by much. Closing things back up was a little awkward because as I mentioned, I wasn't bold enough to disconnect anything. I tucked the bottom case under the board, spent a little time wriggling things into place, and screwed it down. Once done, the black plastic sheet, display and keyboard boards sit neatly on top. Freshly cleaned and screen polished, I put the top case back into place. I've found with a few attempts at opening and closing the case that it pays to make sure the left side is seated just so, otherwise there's a bit of loose flex in it after things are closed up. Polishing the screen cover was a non-event. I bought a Novus plastic polish kit on Amazon which came with three bottles. The first bottle is a cleaner and finish, the second bottle is a mild buffing compound, and the third bottle is a more aggressive compound for deeper scratches. I followed the printed instructions provided with the kit, which were simple. There's a cleaning step not worth describing, a scratch treatment step which is simply buffing with compound #2 perpendicularly to each scratch, and then a third step to coat, dry, and buff the whole surface. Once done, another pass with bottle #1 to clean. I wound up doing the #2 buffing step three times to get satisfactory results. I didn't need to use the third compound at all. My screen is not totally perfect as a result, there's still some extremely faint and shallow marking from my poor buffing technique, but it is beautifully clear. It takes close inspection to find any flaws at all. The Novus kit is fantastic and I will gladly recommend it to anyone wanting to freshen up their screen cover. Someone with more practice at buffing small objects will get even better results than I did.
