Ian Primus

I've found cash in consoles before. Just a few weeks ago I found a couple of pennies in a Nintendo 64! Ok, so it wasn't much cash... I know that over on the arcade forums, there is the occasional "weirdest things found in games" thread. Some people have found large amounts of money still in the cashboxes of old games. Most I've ever found was something like three bucks worth of assorted coins in the bottom of a game. But, at the same time, I'm glad I never found the petrified rats or swarms of cockroaches inside a game either. -Ian

Thanks guys! Yeah, it was a lot of work - but the end result was well worth it. Now to tackle some of the other assorted arcade projects around here... -Ian

Fix it! Definitely. Any classic game, in it's original dedicated cabinet, is well worth fixing. Especially an awesome game like Qix. There are tons of old, converted cabinets out there you can Mame, or games that are already missing all their original parts. Fix the board - unless the acid damage is extensive, it's usually very fixable. Desolder all affected parts, clean the board of corrosion (white vinegar), clean up any residual vinegar (alcohol), and replace damaged parts. ROMs can be replaced super-easy, thanks to MAME. Most chips are readily available. And often, you just need to replace the socket - the chip can be saved by cleaning off the corrosion. If you want, post a picture of the board, and I can give you some pointers. -Ian

Never use sandpaper on a cartridge or the console! Clean your games properly, and they should work fine. The Atari is a very robust console. Clean the contact fingers on your game cartridges using isopropyl alcohol on a q-tip. Scrub hard, and keep cleaning until all the black gunk comes off. You can't damage the contacts with a q-tip - but sandpaper will take the gold plating off. Use 91% alcohol if you can get it, if not, 70% works good too. Clean your console by folding over a bit of computer paper to the thickness of the cart slot, and gently fitting it in there. Do this a few times - add alcohol to the paper if necessary. Most of the time though, the Atari consoles don't need cleaning - but some careful maintenance won't hurt. -Ian

A day and a half (Saturday afternoon, and most of Sunday). I think I spent probably 20 bucks in parts, and nearly $200 for the machine itself initially. -Ian

Here is what it looked like before I started. Sorry that some of the photos are a bit fuzzy, the game is in my garage with the door open, and the sun screwed with the camera in some shots. http://i250.photobucket.com/albums/gg280/R...botron_dead.jpg This was taken when I'd unloaded the game into the garage. It doesn't really look too bad, especially since my camera managed to miss the bottom of the game... But, it doesn't work. http://i250.photobucket.com/albums/gg280/R...ttom_before.jpg A fuzzy picture of the inside bottom of the game. Note the switchmode supply tossed in the bottom. This is plugged into the service outlet - but nothing else. http://i250.photobucket.com/albums/gg280/R...door_before.jpg The back door of the game. Fuzzy picture - but you can see that most things aren't connected. One of those not-connected things is the control panel harness. http://i250.photobucket.com/albums/gg280/R...p_connector.jpg Oh look! The control pannel connector. How... nice. http://i250.photobucket.com/albums/gg280/R...cp_ratsnest.jpg Look at this wonderful control panel wiring job! http://i250.photobucket.com/albums/gg280/R.../metal_clip.jpg Anyone spot the shock hazard? http://i250.photobucket.com/albums/gg280/R.../ps_horrors.jpg Three power supply problems, all within a few square inches! Can anyone spot them? http://i250.photobucket.com/albums/gg280/R...d_soldering.jpg Here's a better look at one of them... http://i250.photobucket.com/albums/gg280/R...itor_before.jpg Where's the components? This monitor seems to operate using nothing but a board covered with filth and dust! And.. here's what the game looked like after I rebuilt it. http://i250.photobucket.com/albums/gg280/R...ottom_after.jpg Look! I can see the transformer! Note that in this shot, I've still got the switcher plugged into the service outlet. I still need to wire it up right. http://i250.photobucket.com/albums/gg280/R...kdoor_after.jpg Here's the boards, all wired up properly, and connected to the switcher. Note the homemade mounting brackets for the power supply, and the new control panel harness. http://i250.photobucket.com/albums/gg280/R...iring_after.jpg The control panel wiring looks so much better now. And it works too! http://i250.photobucket.com/albums/gg280/R...nitor_after.jpg Monitor chassis all cleaned up, recapped and working. http://i250.photobucket.com/albums/gg280/R...een_working.jpg It's alive! It's alive! Now why can't those logos stay still for the picture... http://i250.photobucket.com/albums/gg280/R...er/robotron.jpg And a picture of the front of the game. I realize now that I forgot to put the bezel back before taking this... Oh well - you all know what a Robotron bezel looks like. I had pulled it off to clean it better, and just haven't put it back. The game is working, but the flash washed out the screen. The cabinet really doesn't look much different - I just cleaned it, I didn't go all out and repaint it or anything. My game repair skills are on the electronic side of the fence - not the woodworking side. http://i250.photobucket.com/albums/gg280/R...num_channel.jpg And here's a shot of the bottom of the game sporting it's new aluminum channel. This stuff is great. It costs about ten dollars for eight feet of it at Lowe's. It cuts easily, and it fits nice and snugly over the edge of the plywood. It's fastened in place with small nails. Drill the nail hole in the channel first, but not into the plywood. Then hammer in the nail. The small nails can't punch through the aluminum themselves. This stuff will prevent the bottom of an already damaged game from coming apart any worse. -Ian

Apologies in advance for such a long post. I typed this out after spending two days working on rebuilding this game. It was so long, that when I posted it on the klov forum, I had to split it into two posts (10,000 character limit). Pictures in the next post. Anyway, thanks to Craigslist, I became the owner of a very much non-working Robotron. The only thing I knew when I bought it was that the CPU and ROM boards worked (the seller had swapped them into a Joust and verified they passed the self test). This machine had a lot of major issues, but at least all of the parts were present and accounted for. Ironically, this particular Robotron is in a Joust cabinet - but it's exactly the same style as Robotron! Must have been an early run Joust. First inspection of the game revealed the sad state it was in. The wood around the bottom edges is splitting, and the lower front right corner is bent in a bit. The upper half of the back door is missing. The power supply isn't connected properly, and there is a second, aftermarket switchmode power supply laying in the bottom of the cabinet, partially connected. The control panel wiring harness is cut off a few inches from the interface board, and it's connector crudely patched onto some twisted pair telephone wire with duct tape - and this phone wire goes up to the control panel, where it is soldered badly to the switches. The control panel has a Robotron overlay, but it was originally a Joust panel - the underside reveals the mount for the Joust stick, the two start buttons have been mounted using the caps from Snapple bottles as washers, and their leaf switches are mounted using bits of plastic silverware as spacers. The joysticks are standard microswitch types - not the proper Wico leaf sticks. Inexplicably, the ground wires from the control panel are connected to the metal brace inside the panel... which isn't connected to anything else. Examining the original power supply reveals more bad repairs. The rectifier bridge has been replaced with another one with a different pin spacing - and it's attached using inch-long bits of wire, and hovering above the board. The solder joints on the rectifier itself are cold, bad joints, and one is loose completely. One of the fuses has been bypassed with a scrap of wire. The transformer connector must have burned and been damaged - one of the wires is soldred directly to the pin on the board. Further up in the cabinet, the upper interlock switch is held closed by a bent bit of metal - a bit of metal which is touching the spade connector on the back of the switch - better not touch that while the game is plugged in... The previous repairman must have not known that you could just pull the switch _out_. The speaker grille on the front has a hole in it, as does the speaker it's supposed to protect. Why they didn't make those grilles out of metal is beyond me. Oh, and the filth. The entire inside of the cabinet is coated in it. The monitor is so covered in crud that I can't see the board. This game has never been cleaned. Just wiping the face of the tube with Windex and a paper towel removed a healthy, thick black grime. First things first, I need to clean this. I started by disassembling the game, removing the metal plates the boards are mounted to, the power distribution block, monitor, control panel, bezel, marquee, everything. Vacuuming and cleaning out the inside of the game make a huge difference. I scrubbed the cabinet inside and out with Murphy's oil soap and water. Then, I tipped the game onto it's back, and propped the base up with a saw horse. This allowed me to squirt wood glue into the delaminating plywood, and clamp it back together. This was able to straighten out the bent corner, and fix the outer layer from seperating any more. Once that was dry, I added aluminum edge channel around the bottom edges. This isn't original, but it hides the rough edge and the bottom edge chips, and prevents it from getting any worse. While I was down here, I replaced a rusted and damaged tee nut for the front right leg leveler. I intended to put all new leg levelers on (it only had two and a half of them when I got it), but the ones I had on hand were too short for this game. I'll have to order some longer ones. While the glue was drying, I was able to tackle some other things. I cleaned the monitor tube and chassis, and recapped it. The monitor now produces a steady, bright picture. The tube has a fair amount of Robotron screen burn, but it tests good and strong on all three guns, and it's still very clear and bright, so it stays. Once the cabinet was good, I was able to size up the power supply situation. The original linear supply was badly hacked up, and I really didn't feel like rebuilding it - especially since there was a switchmode supply here already. This switcher is unusual. It looks like a computer supply, but it's a different form factor than the normal AT style. Also, the power cables coming off it are clearly intended for a Wiliams game - there are three connectors, neatly labeled with 'CPU" "ROM" and "SOUND". I disassembled it and cleaned the considerable crud out of it, and cleaned the fan. While I had it on the bench, I hooked it to a dummy load (a car light bulb), and tested it out. All of the voltages were good, and it seemed to be working properly. I verified that the CPU connector has the necessary -5v line for the 4116 DRAM. So, I have a good, working switchmode supply. But how to mount it? It doesn't have any sort of mounting holes or tabs at all, and when I found it, it was just laying in the filth at the bottom of the cabinet. I ended up building a couple of brackets from the leftover aluminum edge channel. One mounts to the front of the supply, using the two lower fan screws to hold it, and the other I screwed into the bottom of the air vents on the other side, using sheet metal screws. And yes, I did check to ensure the screws wouldn't hit anything. I then drilled holes in the brackets, and mounted the new switchmode supply where the original linear regulator board used to mount. It fits absolutely perfectly there, and the cables _just_ reach all the way out to the CPU board. Makes me wonder how this was supposed to be mounted - as it looks like a professionally made replacement supply. I dusted off the logic boards, and I replaced the battery holder on the CPU board. This game was originally intedned to use three AA batteries to store the high scores and setup information. This has proven to be rather unreliable, due to the poor quality battery holder, but also detrimental, as alkaline batteries are want to leak corrosive gunk all over. Fortunately, the batteries had not leaked yet - but I don't plan on chancing it. I desoldered the old battery holder and fitted a modern coin battery holder for a CR2032. This little lithium battery will last as long (or longer) than the AA's in this application, and it won't leak either. Next on the agenda was the control panel. The harness that goes from the control panel to the cabinet connector is missing, and the cabinet's harness has been cut up, so I opted to build a new one. Using scrap wire from some other partial/scavenged harness, I built a bundle of wires that plugs into the interface board, and terminates in a 12 position molex connector. Similarly, I rewired the panel, removing that awful mess of phone wire, and fitted that with a mating connector. The harnesses took a long time to make, but it sure looks (and works) much, much nicer than the mess that was there. Reassembling everything went smoothly. I mounted all the boards back into the cabinet, neatly connected and secured all the wires, double checked everything, crossed my fingers and plugged it in. It lives! "FACTORY SETTINGS RESTORED". OK, now how do I get off this screen. Pressing ADVANCE inside the coin door does nothing. Hmm. Check the schematic - right - the coin door switches all ground through a seperate connector. One that plugs into the old power supply board. I found the loose connector inside, pulled out the ground wire and grounded it. Power back up, and the switches work. Game comes up nicely, and I can coin up and start a game. Two things are immediately apparent. I have no sound, and I can't move. I can fire, however. I can fire in all directions. But I can't move. Adjusting the volume control does very little - but if I turn it up all the way, I can just barely hear the game sounds coming through the damaged speaker. First, I tackled the controls. I ruled out the switches and their ground connections by grounding a clip lead and touching it to the wires on the switch terminals. Nothing. The I tried touching it to the back of my new harness connector - in case I had a bad connection on one row of pins. Nothing. I powered down and examined the schematics of the interface board. I can see that all of the switches go through some 4049 CMOS inverting buffers before going to the I/O chip. Looking at the board, I see... an empty socket. Huh? That's supposed to be IC6 - a 4049 - and according to the printset I have, it handles up, down and left for both movement and firing. That doesn't make sense, because all four directions for fire work, and move right doesn't work, even though it's supposed to go through IC5, which is present. But, no matter - schematics aren't always correct, and I know there were a couple different revisions of interface boards. I had a very badly damaged Defender interface board in a pile of junk boards scavenged from a previous warehouse trip, so I dug it out. This board won't work with Robotron, and I don't think it'll work period - it's corroded, bent, and crunched from laying on the floor in a filthy warehouse for years. But, it has the chips I need. The solder was too corroded to melt properly with the iron, so I used a heat gun to heat up the board, and was able to pull the chip out. I plugged the chip into Robotron and powered it back up - and I can move! All the controls work now. I played a quick game. All the sounds are there, but they are extremely quiet. So - on to repairing the sound. My first suspicion was the speaker itself. It had a big hole poked in it, and while it was producing some sound, I thought that it could very well be damaged enough to prevent it from producing much sound. I had a spare speaker laying around, so I swapped it out. So, now I had a nice, clean speaker in there, but still very little sound. I double checked all the wiring to the sound board. I verified that I do, indeed have the speaker and volume control connected properly (the connectors are the same, and right next to each other). I checked the fuses on the sound board - good. I checked the switchmode supply's connector, and verified that there were four wires, +5, +12, GND, and -5. Then I checked them with the meter. I got nothing from -5. I checked between -5 and +5, and got... 5 volts. The supply was wired wrong!!! The -5 line to the sound board was the same color as the -5 wire going to the CPU board. But it was actually ground, not -5v! A quick cut and splice into the real -5v line on the power supply's harness, and I had sound, and plenty of it. Piecing the rest of the game back together went nicely. I put a new bulb in the marquee light, and that works well, I cleaned up the plastic monitor shroud and reinstalled that. Put the bezel and marquee back in. There are only a couple of minor little things left to do. For one, I need to properly wire the power supply's AC input into the power distribution block in the bottom of the game - right now the supply is just plugged into the service outlet down there, so it isn't switched with the rest of the cabinet from the power switch/interlock. It's OK for now as I've been unplugging it during testing, but I'm going to wire it in properly before it goes in with the other games. I also need to find some longer leg levelers. Not urgent, but it would be nice to have them there. Both coin mechs are extremely gunky, and need to be cleaned and lubricated. I also need to remove or secure the coin lockout coils. Since I am not using the original supply, I don't have 27vdc to connect them to - and I really don't need them for anything. Similarly, I need to wire up the coin door lamps. Those just use 6.3vac, so I can just hook them up to their winding on the transformer. Oh. And I really suck at Robotron. So far, my high score is only 60,000 - and that was a fluke. Next highest was 30,000 or so. -Ian

Wow, I'll have to start saving my games that were made without end labels! I think I have a Pac-Man, Combat, and Asteroids with that label variation. And don't forget the famously rare "Stealth Frogger" cartridges! -Ian

But the problem there is that you open yourself up to a very easy way to accidentally short things out. I don't want to go slopping conductive goo on things, trying to get a solid connection. With solder, it's easy to get it to flow and stick to a pad, it won't flow on non-solderable surfaces, and if you do bridge a connection, it's real easy to fix it - just heat both connections again, and the excess solder sticks to the iron. These connections are small - I just don't see how conductive glue is going to be easier than soldering. If you don't know how to solder, you're doing yourself a disservice. Take the time to sit down and practice on some junk electronics. It's really not that hard, and once you get the hang of it, you will have no problem. Remember - solder isn't a glue. It's not a hot glue gun for metal. Heat the connection, not the solder. Heat the point you want to apply solder to - then flow the solder onto the hot component lead. This will allow the solder to flow onto the part and stick. You can't just drip hot solder onto something with the iron and expect it to stick. Take apart some junk, practice soldering. You should have the hang of it in short order. -Ian

It is possible to damage a chip by heating it. But it takes a lot of heating and a lot of careless. All chips are heated when soldered, all components are heated when soldered. These things will withstand a large amount of heat before being damaged. I routinely scavenge parts from junk boards with a heat gun (or a propane torch) - so far every chip scavenged has worked fine. Even a couple of 7404's I accidentally melted a bit. If you try, you could definitely damage a chip with a soldering iron, but in the couple of seconds you'll be heating it, there is no worry. I have solderred to many, many chips. Many smaller than the lockout in an NES. I've done the pin 4 mod, but I never bothered to switch it (I don't have an NWC cart). I have installed similar circuits in different machines though. I routinely build cartridges, which involves a lot of chip-soldering, track cutting, pin bending, etc. Never damaged one yet. I once scavenged a lockout chip from an NES cart and soldered it into a Sachen game though, to get around that horribly faulty lockout-defeat circuit in that cart. They _can_ be damaged. But again, it takes some doing. This stuff, especially the simple parts in a Nintendo, is actually quite hard to break. You'd be hard pressed to damage a chip while soldering to it. You're not going to be able to solder without heating. Yeah, you could probably tape the wires, but that's unlikely to hold up, and you are more liable to cause damage that way - by loose wires shorting things out. Not to mention the fact that it'll take longer to tape the wires right than to just solder them. Here's what you do. Open the Nintendo and find the lockout chip. Using a pointy pair of wire cutters, clip pin 4 close to the board. Gently bend the pin out and up a bit. Use your soldering iron, and tin the pin you just bent, as well as the pad that it used to connect to with a small amount of solder. It shouldn't need to be heated for more than a second or two - if it does, you're doing it wrong... Take some thin wire - I like to use 30gauge wire-wrapping wire for things like this, but wires from old ribbon cables work great too. Strip about an 1/8" off the end of two bits of wire. Tin the end of the wire with solder, and trim the wire a bit (the insulation will have shrunk back a bit from the heat). You want just enough exposed wire to fit on the connection, no more. Heat the connection on the board where pin 4 used to go, and insert the end of a wire, then remove the iron and let it cool. Hold the wire still while the solder cools, lest you make a cold joint. Repeat with the upwards-bent pin. Then, solder the other ends of the wires to a switch. When the switch is closed, the lockout is enabled. When the switch is open, it's disabled. Easy. And here's another valuable tip. Never, ever, ever use that stupid "lead free" solder if you can possibly avoid it. You'll have no end of troubles making it flow and stick. Especially since you are trying to solder to parts that already have standard solder on them. For all electronic projects, you want standard 60/40 lead/tin rosin core solder (or similar). Likewise, never use the acid core plumber's solder, for obvious reasons... -Ian

But that can fry the chip & stop my NES from working. How can that fry the chip? I don't understand. You want to modify the console with a switch, but don't want to modify the console for fear of breaking it? And if you do manage to kill the chip, you can just replace it - the same chip is used inside every licensed NES cartridge. Just steal one from Mario/Duck Hunt or something if you need one. But, again, it's _really_ going to be hard to break the chip. I can understand the deisre to not have molten solder flying around, but I don't understand the last part. How could you break the chip with the heat? Provided you don't use a blowtorch, you should be fine.... I don't understand what you're looking for here. -Ian

The cheapest possible method is to simply cut pin 4. That's it. No switch, no nothing. It's internally pulled down, so when disconnected, it'll disable the lockout entirely. The machine will then boot all cartridges. If you really want to switch it on and off, then you need a switch, some wire, a soldering iron, some solder, and something to cut the pin with. A tiny pair of dikes (diagonal cutters) is ideal, but you can even use nail clippers. If you would rather desolder the pin, then you can usually get away with heating the solder point and pulling the pin out with a bent safety pin or something - but I'd recommend clearing the solder out of the hole first, by using a solder sucker, desoldering pump, wick, whatever. Or just heat the connection and quickly whack the board on the table - if you do it right, the solder will come flying out. -Ian

Huh? CRT TV sets _are_ designed to display all colors. That's what they do. Remember, television signal is ANALOG - there is no, nor was there ever, a limit to how many colors a (color) set can display. Televisions are not, however, designed to be computer monitors. The effective resolution you're going to get out of them isn't going to be great, the edges might not be clean sharp lines, and the lack of precise HV regulation means the picture is going to change size slightly as the picture changes from light to dark. But you shouldn't get color bleed. I would fiddle with the controls for the output of your TV card, and the color control on the television. I agree with cwilkson, it sounds like the saturation is up too far. Test other sources on the S-video input, and see if they produce the same problems. Ideally, use a DVD player conneted to the s-video connector, playing a DVD - then put the DVD in the computer, connect the computer to the same s-video connector, and compare the picture. Another thing that can cause picture ghosting is poor quality, overly long, or damaged cables. Try another S-video cable. Just for grins, try composite if your card offers it. -Ian

Use whatever tools are familiar and comfortable to you. I personally prefer to use a standard pencil iron and a seperate desoldering pump, while others like the heated desoldering irons, and others use desoldering wick. For such a simple mod, you really don't need a desoldering iron. You can just clip pin 4 flush with the board and bend it straight out, and solder to the stub of the pin on the chip, and the pad where it used to live. -Ian

It's an RS-232 to USB adapter. It's used to connect older serial devices to newer computers, which are sorely lacking in serial ports. -Ian

Ugh, tell me about it. I have been accumulating for years. Actually, the console gaming stuff takes up the LEAST space of all the things I own. I also collect old computers. And yes, this means large iron. I've got single computers that weigh over 600 pounds. And hard drives that take two people to move. Not to mention arcade machines - those are easy, because they're so light in comparison. You can move those around with a hand truck, no problem. -Ian

Depends on the marquee - some older ones are glass, newer ones are plexiglass, the real cheap conversion kind are just thin plastic of some kind, and some are made of "unobtanium". Making a marquee is actually pretty simple. Just cut a piece of Plexiglass or Lexan (available at the hardware store) to the right size, and have your artwork printed out on something and cut it to the same size. A friend of mine went to Kinko's and had something printed on some sort of plasticy paper - it worked perfectly. Just cut it to the size, put it behind the plexi, and bolt in place. With the light in the cabinet, it looked great, and it only cost him a few bucks. -Ian

Just replace the connector. You can steal one from another 7800, a 2600, or probably a Sega Genesis. Don't have the part number off hand, but Best Electronics should have it too. -Ian

That sounds like the Atari I just modified. I wound up just soldering everything to the TIA, rather than bothering to trace out where everything went on this board. I just bent out pin 6 of the TIA and soldered the brown wire to it instead of removing any resistors. -Ian

*bump*

Well, I finally got around to building the Longhorn mod last night. I had great success with it, the picture looks really good, however the vertical band problem is somewhat noticeable. I'm getting the slightest amount of color bleed as well. This was testing on an old Sony CRT video monitor. These problems could have been created by my minor deviation from the design, however. I should have taken pictures, but it was late by the time I got it working. I built mine from scratch, using a small Radio Shack perf board. I had to make a couple of the odd value resistors as well (9.1k, 2k). I did use the TI 74..CD4050, however. Also, I couldn't find a 47pf cap so I threw a 51pf in there, and I left out the FM6400's filter cap (10uf). I built mine only for composite video, so I didn't put the 75ohm resistors on the chroma or luma lines. I also skipped the stereo sound, coupling the audio output to the TIA pins 12/13 through a .1uf cap. My 4 switch Atari's board is somewhat different than the one that was used in the install guide, however. I ended up just soldering everything directly to the TIA. Soldering that stupid little FM6400 to perf board is a royal pain. I ended up using an 8 pin DIP socket on the board, so it would be easier to hook things up to it, then soldering the tiny surface mount chip to a 4x4 square of perf board with header pins on it, and plugged it into the socket. But, all in all, it works really nicely. Thanks for the great design! -Ian

Hehe! That bag looks exactly like the ones my cat loves to hide in. They're freebies from Sunmark credit union (where a friend works), and I use them to carry things around frequently. I'll put the bag on the floor, and put a few things in it, turn around to get something else, turn back, and there is now a cat in it. He lets you carry him around in the bag too! Very cuddly, and very curious. Sounds like my Sam would get along well with Stanley! -Ian

13v would be about normal. Remember, when you tested it, the power adapter had no load on it. It's a simple unregulated DC supply, so it'll show a higher output voltage unloaded. A 2600 supply can show as much as 16 volts unloaded. The power supply I was referring to was the one _inside_ the console. The power adapter is only part of the equation. It knocks down the wall voltage, rectifies it and filters it, and puts out DC. Inside the console is a 5v regulator IC (7805), with it's own filtering. Either component could be limping along - as there are capacitors in both places. As electrolytic capacitors age, they tend to develop a bit of an internal resistance, and reduce in efficiency. But without testing, it's hard to say blindly what the problem actually is. I could be totally on the wrong track. At the moment, it's only a theory. I've just had similar problems with EPROMs and poorly-powered consoles, specifically, homemade Nintendo cartridges in a cheap Yobo FC clone system. The wimpy little power supply in that critter can't power NMOS EPROM chips in a cartridge. In that case, however, the problem was simply the external power adapter being under-rated (cheap, cheap junk). -Ian

It could have something to do with the console itself. I've found that sometimes EPROMs can be picky about their power source - more so than mask PROMs. Not only that, but NMOS type EPROM chips draw more current than the mask PROMs do - which could make the problem worse. Measure the 5v supply in your 7800 with no cartridge inserted, with a regular cartridge inserted, and with a homebrew cartridge inserted, and see if there is a change. If there is a change, dipping with a homebrew cartridge inserted, then try replacing the filter caps just after the regulator. -Ian

I wouldn't worry about maintaining vacuum tube equipment. Tubes are still readily available, and should be for a long time. Also, vacuum tubes are far more robust than you might think. They do last a very long time. They also have an infinite shelf life. The capacitors in the old tube chassis TV, on the other hand, are going to likely need replacing. In most cases, even a tube that tests "weak" on a tube tester will still work fine in the TV. I've got TV's and radios dating back much further than that little black and white portable in the Computer Space - and all the tubes are still available from various sources. Not only that, I've run across relatively few bad tubes in need of replacement. And, besides, even if you can't fix or somehow can't get the parts to fix the original monitor - a modern set will work just fine. It's just a composite video signal anyway. Just not "original". I don't feel that keeping arcade machines running for a long time will be that big of a problem. ROMs can be replaced - thanks to MAME, just about every game ROM has been dumped and archived. Most logic chips and RAM chips are easily found. True, there are some custom chips - but even then, some of those have been cloned. If there is a big enough problem with failures in a part, people will come up with replacements. And if the failure isn't a big enough problem, then you should be able to find a used part. Most of us arcade hobbyists have piles of game boards laying around - obtained from operators from long-junked machines. There are more game boards out there than there are machines to put them in. Monitors can be kept running for a very long time, especially in light of the availability of aftermarket replacement flybacks. The good ol' G07 chassis is well known, and all the parts are available. Picture tubes last a fairly long time - and in home use, a good tube should last nearly forever. Power supplies are easily replaced with new switchmode units, and are also repairable with common parts. The long and the short of it is, yes, MOST electrical parts are available. Cosmetic parts are readily available for the most common machines in the form of repros. And there are lots of junker machines that get parted out to save other machines. Not to say there aren't parts that are hard to get - but with a little work and a bit of creativity, I'm confident that I can keep the arcade machines I have running for a good long time. -Ian