Kelpi Posted September 14, 2012 Share Posted September 14, 2012 My faithful childhood Vectrex has started to give me display trouble. Nothing as serious as the dreaded white dot but still very annoying and distracting. I bet you Vectrex experts would know in a heartbeat what the problem is. Here is a short 2 minute video which shows exactly whats going on: http://www.youtube.com/watch?v=cz4AqY6lCFE&feature=youtu.be Im not an electronics man myself but I do have a couple on hand and would love to get this Vectrex running at 100% again. Thank you to anyone that can help. Quote Link to comment Share on other sites More sharing options...
VectrexMad! Posted September 16, 2012 Share Posted September 16, 2012 Its hard to diagnose from just looking at the video. It might be that you need to replace the SY6522 chip (on the logic board) or the LF353 and LF379 chips (on the analogue board). These are connected with screen output. But you should get an electronics person to work with the vectrex service manual and measure with an oscilliscope to verify the expected signals from the components and thus identify the correct operation of the particular circuit. Quote Link to comment Share on other sites More sharing options...
Kelpi Posted September 17, 2012 Author Share Posted September 17, 2012 Thanks! Im trying to compile as much info together as I can before I take it to my electronics man! I was hoping for a easy "ahh see that a million times you just need replace X" but anything is appreciated. At first I was thinking it might be the caps but that doesnt seem to match my research. Quote Link to comment Share on other sites More sharing options...
thevnaguy Posted September 26, 2012 Share Posted September 26, 2012 looks like one of the IC's is going bad. especially when you said it sometimes fires up fine then gets worse as it runs. Sounds like a IC is having thermal issues. or a transistor is breaking down. you may be able to find it by getting some component chill spray and spraying each IC and transistor to see if the display comes back. when it does, you found the component causing you the trouble. Quote Link to comment Share on other sites More sharing options...
Kelpi Posted September 26, 2012 Author Share Posted September 26, 2012 That makes sense and reminded me of something I had previously forgotten. A couple years back when this first started happening I remember at one point taking off the back and directing a large fan onto everything. It fixed the problem but only for a short while. It gives me a good lead though, thanks! Quote Link to comment Share on other sites More sharing options...
Andromeda Stardust Posted September 26, 2012 Share Posted September 26, 2012 (edited) looks like one of the IC's is going bad. especially when you said it sometimes fires up fine then gets worse as it runs. Sounds like a IC is having thermal issues. or a transistor is breaking down. you may be able to find it by getting some component chill spray and spraying each IC and transistor to see if the display comes back. when it does, you found the component causing you the trouble. One time, I had my laptop overclocked, and was running some stress-test software. I opened the back of the laptop and the CPU was 80 degrees C in Speedfan. I turned one of those "duster" bottles upside down and sprayed the CPU heatsink until there was frost on it, then the fan stopped blowing. I was so afraid I'd broke something, until a few seconds later, the frost melted away and the fan slowly kicked back in as the CPU heated up to semi-normal operating temps. My CPU was running sub-zero (below freezing or 0 C) temps for about 15-20 seconds, and it didn't crash my laptop either. LOL, that was probably a dumb thing to do with my laptop as frost could easily short out the components as it melts. I eventually quit trying to overclock it after it crashed three times in a single day. My laptop obviously survived the ordeal as I'm typing on it right now. But please beware of frost/condensation if you're thinking of using an inverted CPU duster to chill components, especially if you live in a humid region like Louisiana. Also those CRTs are built of tough stuff, but beware if your duster can shoots frozen splooge onto the CRT, the thermal shock might crack the tube and you'll be saying goodbye to your Vectrex. Edited September 26, 2012 by stardust4ever Quote Link to comment Share on other sites More sharing options...
Kelpi Posted September 26, 2012 Author Share Posted September 26, 2012 Good point. At first I will focus on the 3 chips mentioned by VectrexMad! See if that gives any joy. Quote Link to comment Share on other sites More sharing options...
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