kynikos

Thanks, I'll give that a go. They are just short bolts now that I looked at them again.

Well, good news - the conductive paint worked! The top row of keys is now working and everything else seems to be fine. Once I got the keyboard out I could see more of the traces across the whole mylar had turned black, so I thought I was in for a bad time, but it worked with just a bit applied to the ribbon part sticking out. Thanks all for the help! I may order a new mylar as a backup just in case but for now everything seems to be working fine. The only thing I couldn't figure out when putting the computer back together was the metal clip on the rear expansion port. It seems to ride under the RF shield tabs. There are two short screws that seem to not bite into anything. Anyone know how that fits together again?

Just got it in the mail today but haven't had a chance to try it out yet. Hopefully will be able to give it a go this weekend if I can get away from the kids for a bit!

I swapped out the 4051s but that didn't make any difference so it must be the mylar. I'm still waiting on the conductive stuff to arrive. If that doesn't work then I'll just get a new mylar.

Thank you! Replacing the mylar seems like it would be a pain.

I'm not opposed to trying the paint fix as I work on a lot of other computer/game console electronic projects so I could probably use it for something else. Do you have a link to a specific product so I can get the right thing? Do you happen to remember how much shipping was on the mylars from Best? I've ordered from them a few times so I know the drill.

Well after getting out the multimeter, there are definitely some continuity issues with the traces coming out of pins 1 and 2 (the top two in the photo I posted). Those two correspond exactly to the row of keys that are not working according to the schematic. I guess I should have checked that before messing with the 4051s. Oh well, replacements were cheap. Some of the black oxidation or whatever it is goes up pretty high to where I'd probably need to take the keyboard apart more to access. At that point, might I be better served just getting a new mylar for it? I don't have any conductive paint so I'd have to spend the money on one or the other. If that's the route I go, is the mylar from Best Electronics still the go to? Many thanks to all for the help so far!

Ok, finally got a chance to open it up. The case screws were still torqued down so I don't think anyone has been inside until me. Everything is in good shape and very clean. It seems like a type 4 keyboard with the metal plate on the back from what I can tell. The mylar has some black coloring near the connector and part way up the top ribbon that goes all the way through one of the lines. I'm not sure if that's normal or indicates an oxidized trace. I planned to try swapping the 4051 chips as suggested but accidentally broke a pin off getting getting one out as the sockets were pretty tight so I have some more on the way to continue testing.

Thanks all! I'm pretty sure I have a type 4 keyboard just going visually but won't have time to open everything up until later this weekend. The seller claimed that row of keys were working before packing it up so I'm hoping its just a matter of something coming loose during shipping. Will keep you all posted!

Hi all, I picked up my first Atari 800XL and everything works great aside from the whole top row of keys (escape -> backspace). None of them register at all. Is there anything I should investigate once I open up the computer? At least it's made in Hong Kong, so everything should be socketed from what I've read, in case it comes down to replacing chips. I've also heard of the mylar going bad as well? Any help would be appreciated to point me in the right direction!

It basically looked like the attached image. I had nothing else plugged in so that might explain it. I'm not sure I want to spend the money on a test harness right now as this is my only C64 and I don't really plan on getting more.

Hi all, I recently picked up my first C64 and am a bit confused after running some diagnostic tests. On both the 586220 and 586220* diagnostics my 6518 U18 is showing as "bad", which I understand is the SID chip. However, when running the SID Tester by Andrew Challis, everything passes and I can hear all the sounds fine. Games sound fine as well. Should I be concerned that my SID dying or would this just be a diagnostic test discrepancy? Thanks in advance!

Please put me down for 2 controllers.

Hi all, I'm looking to buy a Micro Genius IQ-501 console with discrete chips (CPU and PPU). I'm fine with NTSC or PAL and don't care about a box or other accessories. I'd prefer it come with a controller or two if possible. I had one a few years ago but sold it and have kind of regretted it ever since. I'm located in the United States in terms of shipping. Please let me know what you have and name your price. Thanks!

Will the firmware on the pre-production Concerto cart be upgradable? Obviously not for the extra memory support as stated but what about other improvements along the way? Also, do the pre-production carts also feature sockets for a POKEY chip? It looks like it does but just wanted to make sure.