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Thread: 53.693175MHz oscillators?

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    ToeJam is a wiener Hero of Algol Guntz's Avatar
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    Default 53.693175MHz oscillators?

    Anyone know where I can buy some of these? I've got a dead Model 2 VA3 (powers on, cart slot is clean, Genesis and SMS games don't work, TMSS doesn't appear) that might have a dead master oscillator... It's worth a try, I've fixed other dead systems with a new oscillator.

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    Out of curiosity, where'd you get replacement oscillators for your other dead machines? Or were they different speeds?

    Quote Originally Posted by Guntz View Post
    Anyone know where I can buy some of these? I've got a dead Model 2 VA3 (powers on, cart slot is clean, Genesis and SMS games don't work, TMSS doesn't appear) that might have a dead master oscillator... It's worth a try, I've fixed other dead systems with a new oscillator.

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    Co-Creator of the MegaAmp Raging in the Streets villahed94's Avatar
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    You can get the same speed by multiplying by 15 the frequency of an NTSC oscillator.


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    Quote Originally Posted by Drakon View Post
    Out of curiosity, where'd you get replacement oscillators for your other dead machines? Or were they different speeds?
    They were different speeds. For instance, I fixed an original Game Boy with a bad oscillator. It wouldn't display the Nintendo logo, which appears even without a cartridge, so I knew something was broken inside. The Game Boy uses a pretty standard speed. I can't remember it off-hand... I also replaced a 24MHz crystal on an MVS board. Replacing oscillators is always worth a try.

    Quote Originally Posted by villahed94 View Post
    You can get the same speed by multiplying by 15 the frequency of an NTSC oscillator.
    And how might I go about doing that?

    Actually, you've still got a few dead Model 1s, could you send me a 53MHz oscillator?

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    There's gotta be a frequency multiplying circuit out there on google somewhere. With the help of tiido I built a frequency division circuit so you can drive a video encoder using the nes clock signal (provides a more on sync colour subcarrier giving you better s-video). I had to divide the nes clock signal down to 1/6 the speed to drive a ntsc video encoder with it.

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    For simplicity's sake, I think I'd rather take a 53.6MHz oscillator out of a wrecked Genesis. That way, the oscillator can be soldered right into the main board, no fumbling around with a daughterboard.

    Right now though, I'm gonna desolder the master oscillator out of this faulty VA6 I have and fit it into the Model 2, to see if that's the problem. I don't have an oscilloscope, just a logic probe, which I don't think works the same way.

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    I opened up that Model 2 VA3 and I didn't actually find a 4 pin oscillator inside... Not really sure where that signal is generated now.

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    Mastering your Systems Shining Hero TmEE's Avatar
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    You will not find anf replacements. Only bet is a PLL
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    Sorry to bump such an old thread, but did anyone ever find a source for these or does anyone have a broken genesis they could salvage the crystal from for me? I have a switch modded Model 1 megadrive and an OSSC on order and i'm concerned my Sony TV isn't going to like the slightly lower refresh rate.

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    Hedgehog-in-Training Hedgehog-in-Training
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    Thanks good spot, i've ordered some - gonna take 20 to 40 days though!

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    Just to feed back, the crystals from Aliexpress came quite quickly and i've fitted two so far and no problems!

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    Did a bit of reading last night, and realised these Crystals (the Hosonic HO-12C) are pretty low accuracy - +-100ppm, seem to work fine. If any more accurate crystals come up in the future (ie +-25ppm or under) i might upgrade. I guess the crystal in my VA0 MD1 may well be that far out anyway though after 19 years!

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    Hedgehog-in-Training Hedgehog-in-Training JamesF's Avatar
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    I have a question.
    What would be the difference in refresh rate when using a stock crystal NTSC genesis and switching to PAL region, versus using a stock PAL mega drive?
    Sega Genesis Model1 VA6 & Model2 VA4 + Mega Everdrive X5

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    Mastering your Systems Shining Hero TmEE's Avatar
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    Yes.

    53203424 Hz - 50Hz is 49.70146Hz and 60Hz is 59.37617Hz
    53693175 Hz - 50Hz is 50.15897Hz and 60Hz is 59.92274Hz
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