Den Mon, 16 Jul 2018 23:08:14 -0400 skrev "Raj Wurttemberg" <rajaw@c64.us>: > Hi Guys - I just had another 1902 monitor pop (big cap near the > flyback transformer) and I'm getting worried that my CRTs are > reaching their end of life. Have any of you done any work on a > device to convert the output from a C64 to s-video or even better, > HDMI? I can troubleshoot electronics, but I never learned to design > circuits. I did find one schematic on the internet that involves > removing some components from the C64 and putting in an s-video > connector. I'm fine with doing that but I wanted to check with you > all first before starting that process. C64 and C128 already has S-video output, but the name S-video wasn't invented until later so it goes by other names in documentation written back in the days. You need an 8-pin DIN, and it has to be the right kind (there are two kinds, one where 7 of the pins form a perfect circle except a "pin" is missing, and one where pin 6 and 7 "hangs down" like they are tired). Of course use audio out as usual, and signal ground as usual. Luminance is connected to the luma pin of an S-video connector. Chrominance is connected to the chroma pin of an S-video connector. (If you live in Europe you might have a TV with S-video on a Scart connector. Then you connect luma to the video in pin and chroma to the RGB color pin that's physically closest to the video in pin. Of course you also connect the audio signal to the audio in pins). As you seem to be able to do some work on electronics stuff, I suggest that you do a full recap of the monitors you want to keep alive, or at least have a look at the electrolytic capacitors and see if there are any swollen or leaky (physical fluid) capacitors. If any look bad, at least replace all that seems to be from the same batch but preferable replace all. You might skip the small capacitors that sits in places where a short circuit would not damage expensive stuff, like perhaps in the signal path where the signal levels are rather low. But that is imho not worth the temporary saving, the smaller capacitors are also the cheapest to buy new. opt for capacitors with a good reputation and be sure that they are rated for the heat from nearby power semiconductors and resistors, and generally the heat where you live. The only 100% perfect HDMI solution I know of is to emulate the hardware using for example the Turbo Chameleon or the new replacement motherboards. Btw the things that age in CRT monitors seems to be the electrolytic capacitors and the insulation in the high voltage parts. I'm officially denying this, but "I've heard" that you can remove metal parts that are near high voltage parts where the insulation has failed. It might even require cutting a hole in the case, and it will be rather dangerous and something you really don't want to use if there is a risk of animals, childens or uneducated people getting nearby it. Btw if the high voltage insulation has failed in a monitor you usually hear a rather loud sparky sound. Don't hook up such monitor to a computer or anything else you value until you have fixed the insulation. There is another kind of insulation fail that causes a high pitched buzzing sound and a smell of ozone. In those cases it might be sufficent to clean out dirt on the high voltage parts of the monitor. Don't work on the high voltage parts unless you are sure there are no voltage charges still in the CRT. The CRT acts like a capacitor and can hold a dangerous amount of energy. Follow well-known discharge procedures after first letting the monitor rest for a few days. Never ever disconnect the ground shield "nest" from the CRT unless you already have disconnected the high voltage lead an the connector on the neck of the tube. Always keep one of your hands behind you and work with the other hand, and always work in an environment with good insulation (i.e. a dry room with wooden or plastic floor, not concrete or metal on the floor and not in a wet/humid place). Beware that on a broken CRT monitor (and a broken switch mode power supply in general) there might be capacitors charged with rectified mains voltage (about 170V DC in 120V countries, about 325V in 230V countries) that due to the fault won't get discharged. -- (\_/) Copy the bunny to your mails to help (O.o) him achieve world domination. (> <) Come join the dark side. /_|_\ We have cookies.Received on 2018-07-17 22:00:05
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