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Sega/Gremlin Depthcharge
28 Aug | 05Finally moved and in our new place and getting back to work. Got in a Depthcharge that was supposed to be working and only have power supply issues. Hooked up the game board on the bench and guess what? It doesn't work, it's got a short from +5 to GND. Nice! Started looking all over to see if something got bent or there's a lump of something where there shouldn't be. Looking at the back I see someone had to make a huge modification to the original design. The ground trace...
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Captain Fantastic (home version)
10 Apr | 05I ordered the test procedures from Marco. I got a cheaply assembled photocopy manual. The schematics in it are incomplete and have been copied so many times that they are close to impossible to read. First thing I did was check out the power board. Opening it up I found a board that looks very similar to a Midway 8080 style power board. I found the input voltages were fine, but the 5V and 18V out were very low. After checking voltages around the board I found that nothing was getting across the...
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Big Event Golf
25 Mar | 05 -
Strange color to alphanumerics, part II
13 Mar | 05Found it! It was the RAM chip at 10M. The chip itself was fine, but the trace to pin 16 was intermittent. I got the board with a socket already at that location, and I'm guessing that when the chip was pulled out the board got damaged. I also found that flexing the board would get it to work briefly.
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EPROM Problem
11 Mar | 05Got a board in that when it booted up the attract screen was messed up. Colors of characters aren't quite right Flexing the board around the area of 1A cleared up the problem. Looking at the back of the board I see someone tried to reflow the solder around a bunch of the sockets. I'm going to start ripping them up one at a time and replacing them with new clean ones. Update: Replacing the socket at 2A fixed it.
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