I picked up another Commodore 64 quite cheaply. This poor system had been stored in some bad conditions. I am not sure the conditions, but it had been wet at one point at least and damp quite a lot. When it was put there, it was probably pretty rough looking as far a browning of the plastic. This was an early Commodore 64 from 82 originally. Oddly the serial number label had no serial number printed on it. I have seen some labels that ink can be removed from by some cleaners, so I don’t know if it had been wiped off or never had a number.
Internally it as all there. The old paper foil shield was dirty and had mold on it. There was dirt and dead bugs all inside it. The first thing I did was pull the paper shield and toss it out, I then pulled the keyboard and mainboard out. Next I hosed the worst of the dirt and bugs out of the case with a hose.
Next I removed the bottom shield from the mainboard. It showed quite a bit of corrosion on it.
Before I tried to fire the board up, I did a bit of cleanup on the board itself. Then I looked it over to see if anything needed addressed before trying to power it on. I first checked that the power switch was making good contact. I then checked the Fuse was good. I also pushed all of the socketed chips in to make sure they were tight.
Looking over the board it was dated as 1982. There are some odd things about this board, it has had all the main chips socketed (all “wide” chips). The main chips are also all dated 1984. Three of the ram chips have been replaced and are also dated 1984. The remaining chips are all from 1982.
The next odd thing about this board is that it has a 8 Pin Video Socket instead of the 5 Pin Video Socket that was originally on it. julrod over at Lemon 64 said he had heard that Commodore service centers had upgraded the 326298 boards with 8 Pin Video Sockets. I have yet to test if the 8 Pin socket includes the added Chroma signal for S Video like video output. Looking around the 8 Pin Video socket I saw 4 cut traces (some on the bottom some on the top) around it and there are two wires on the bottom side leading off to points on the board.
I connected the cleaned up board to a display and my power supply. It actually came up to the normal startup screen showing all of the memory. The video was noticeably poor compared to my other later Commodore (a 1984 model). It has bad Jail Bars on the screen for one. I then connected up my full test harness an test cartridge. The board passed all of the tests. I fired it up with my Pi1541 and started up a game.
The next day I spent doing a lot more cleaning of the computer. The case was cleaned with some CLR Mold and Mildew cleaner, a brush and a toothbrush. It still looks bad due to the lack of the badge, the bad browning of the plastic. The plastic is streaked oddly in the browning as it isn’t very uniform. The top has a crack on the right front corner. Three of the mainboard mounts are sheared off. The narrow right tab is missing that holds the back on. Two keys are missing and the posts are broken on the keyboard. The keyboard worked, but it wasn’t very responsive. It is quite dirty as well of course.
Most of the screws are rusty. Some of them are very badly rusted, anything in the “front edge, including the base screws. I put them into some vinegar. After soaking in it for awhile, the rust was removed from them. It left them looking a bit different, but they were in much better shape. I also did the same with the keyboard springs.
I removed the cage around the VIC II area. It was quite rusted, and I don’t like them anyways, as it makes it hard to get to the parts inside. It may be a decent heatsink for the VIC II though, I replaced it with a real heatsink though. The computer has a factory mistake where R10 by the VIC is 300 Ohms where it should be 120 Ohms. Ray Carlsen recommended putting in a 220 Ohm resistor in parallel across the existing R10 to bring the resistance to what it was supposed to be. This corrects the resistor in at R10 brings the strength of the Composite Video output to what it should be.
Here is the keyboard disassembly.
I lightly cleaned the keyboard pcb with some IPA. Once it was put together again, it did seem like it was more responsive. I haven’t tested it fully though. Keep in mind that too much cleaning of the contacts will rub the carbon off and they won’t work properly.
For the keyboard I turned to a little inspiration from Perifractic at Youtube. I had to tear down the whole keyboard to clean it properly. It also wasn’t making good contact on some keys, so I decided I would clean the pcb on it. I don’t have spare keys, or posts. I decided I would try repairing the broken keyboard posts with some pieces of Lego Cross posts. It does look like it may work, I don’t know for how long though. The one key the “pound” key is one that I doubt I will end up using, so having a repaired post there shouldn’t be a big deal. The other key was the 8 key so I decided to move that post to another position where it will get less use. To do this was a combination of a drill bit, using a Dremmel, and Xacto knife. While the Lego Cross axel looks like the key post top, the problem here though is that it is just a bit too large. A Lego piece that accepts the Cross Axle will go on a Commodore Post, but a Commodore Key won’t got on the Lego Axle. I don’t know if some of the Lego Axles are a little different or what though the ones I had wouldn’t work with the keys properly. I ended up using a small file to file them down to a more fitting size. I found that superglue won’t get a great bond on Legos, Bondic doesn’t either. I did try some model glue, which was said to be able to fuse Lego pieces. I don’t know how well it is holding. I may eventually replace the damaged posts, but for now they are hopefully ok. I still need to get 2 springs and two keys.
I reassembled the keyboard with the repaired posts.
I also took the top off of the Modulator and cleaned and polished it up. The plate on the Cartridge Port had some bad rust on it as well. I desoldered it from the board so that i could get it properly cleaned up. They both turned out to be a good improvement. I was going to paint these pieces but decided not to. Instead I put some teflon liquid to try to protect them from rusting quickly. I also used it on the screws. It puts a bit of a coating on stuff and is used to protect tools from rusting as well. The other part/parts I pulled to clean up were the two parts of the Fuse Holder. They were badly corroded. I desoldered them and polished them.
The board now looks quite better. I also installed heatsinks on the VIC II, SID, PLA, and CPU.
The conditions left the metal plate around the power LED corroding and the paint lifting off. I ended up cleaning it as best I could. I have to figure out what to do with it for painting etc. The main case badge was missing, and from the condition of the browning of the plastic , it must have been missing for a good while.
In an effort to get the old case looking a little better, I scrubbed the case with a paste of Baking Soda to get some of the marks off of the plastic. It did get rid of some of them. The plastic is still streaked brown.
For the crack in the right front corner on the top, I melted the plastic from the inside with my solder iron set to a lower temperature. This held the part in place, but for the crack on the outside, I used some model glue, that seems to have fused the plastic there pretty well. I also put a little on the inside to even out the melted plastic. Be careful about getting too much of that stuff on the plastic, it will dissolve it making it soft. It may not harden properly again if that happens.
Some of the pins in the components were rusted, and rusted badly on the bottom side. So I thought I would just clip them closer to the board. When I clipped at least two of these they just came right off. They were rust clear to the solder. I don’t think they were rusted below the solder. I tried to remove as much rust as I could. The presence of rust encourages the formation of more rust unless I am mistaken in what I have heard.
So far restoring this old beat up 64 has mostly been a lot of cleaning and some physical repairs. I did do the R10 fix. I still have more to do with it, and I am not sure when I will find the proper replacement keys. I was thinking of just ordering any key to put on the keyboard so I have a full keyboard, but I am not sure yet. I will probably recap the board. I have to fix those 3 board mounting standoffs that are broken off. I may fix the broken case tab on the right as well. The heatsink on the 5 Volt regulator is a bit loose, so it won’t be making the greatest thermal transfer to it. I will see about fixing that up before using the computer too much as well.
I am looking at the options for replacing the case badge. I also plan to paint this case and not to try and retrobright it or anything like that. The letters on the keyboard keys are also yellowed. On the left side it isn’t too bad, but as you go across the keyboard it gets quite bad. This computer will never be the best show piece. I think I like it though for the 8 Pin Video on the early board, and the main chips being socketed. I could easily use this board to test most of the typical breadbin primary chips. Being is such poor physical shape gives me a bit of freedom as this case will never be “like new” again, I can do what I want and not have to feel like I am harming it. It is a bit unique and it will remain so. I didn’t check the Chroma output on that 8 Pin video port yet, but I will get around to that probably later this week.
Once I was done cleaning it up, and I finally put the keyboard back together I fired it up again to try out a game again. I “think” it looks a little better onscreen. It still has noticeably worse jail bars than my other Commodore 64. I am only using it on my little 7″ composite display so I don’t know how bad for sure until I put it on a bigger display.
As I make progress on the restoration of this Commodore 64 I will probably do a followup post on it.