Mega CD 2 repair question...

Discussion in 'Repair, Restoration, Conservation and Preservation' started by Lostdotfish, Nov 16, 2018.

  1. Lostdotfish

    Lostdotfish Active Member

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    I've just picked up a seemingly dead mega CD 2. The fuse checks out but I'm getting no power, no drive movement, no power led etc.

    Before i start fault finding, if I disconnet the optical drive completely, will the mega CD still make it to the start up screen or will it being unplugged stop it starting?
     
    Last edited: Nov 16, 2018
  2. Lostdotfish

    Lostdotfish Active Member

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    Further to this;

    Setup - PAL Mega Drive 1 - PAL Mega CD 2

    Mega CD 2 is generally in good clean condition internally and I've given the slot a good clean with IPA.

    Current symptoms - Mega CD does not power up - no LED no disc spin

    So I've done the initial tests.

    PSU is fine
    Fuse is fine
    V Reg is spitting out 5v on pin 3 as expected

    When I power cycle the Mega Drive my TV does detect a signal (576p) and I see some slight ripples in an otherwise totally black screen.

    Just wondering what my next steps should be?
     
  3. Oakleaf

    Oakleaf Spirited Member

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    it will boot without the cdmech. there are several fuses. check them all. also if u fix the power issue. make sure to clean the blade switches so to not blow the fuse again.
     
  4. Lostdotfish

    Lostdotfish Active Member

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    Are you sure? I only see F301 on the schematic and BoM for the Model 2 Funai Mega CD I'm working on.
     
  5. Oakleaf

    Oakleaf Spirited Member

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    there are at least 2. one on the top side of the board and one on the bottom. I remember cause i got a broken one a couple of years ago. It wouldnt power on. I turned to google saw it was a common problem. However the fuse listed in most places was working.
    It turned out to be another fuse that was blown.
     
  6. Lostdotfish

    Lostdotfish Active Member

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    There's definitely only the one fuse on my board revision.

    https://console5.com/wiki/File:Sega_CD_2_-_Mega_CD_2_-_Service_Manual,_Number_002,_August,_1993.pdf
     
  7. Oakleaf

    Oakleaf Spirited Member

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    this vid describes the two fuse variations. The one that mine had was the surfacemount type.

    I se you might have the other kind.
     
  8. bart_simpson

    bart_simpson Dauntless Member

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    If not the fuse is bad check the nec power reg.
     
  9. Lostdotfish

    Lostdotfish Active Member

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    just updating this for prosperity. I received my Mega Sg a few days ago and decided to let it have a go with this Mega CD. I finally got the Mega CD to boot to a BIOS screen and subsequently loading games. I'd previously tested it with 3 original Mega Drives (2 MK1s and a MK2). It has to be an issue with the edge connectors on the expansion ports on those consoles as the shiny new Mega Sg just works.
     
  10. segasonicfan

    segasonicfan Robust Member

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    That's strange. I doubt your system is fixed, but you probably have an issue with the VREF, or similar signal that the new system doesn't use.
     

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