Results 1 to 11 of 11

Thread: Sega Mega Drive / Genesis OEM PSUs - capacitor failures

  1. #1
    Mickey's Coach

    Join Date
    Apr 2013
    Location
    PL

    Posts
    749

    Sega Mega Drive / Genesis OEM PSUs - capacitor failures

    TL;DR - check the capacitor in your Sega Mega Drive / Genesis OEM PSU - most likely its failed and leaking electrolytic fluid.

    I was having a bit of a problem with my Mega Drive 2 + Mega CD 2 combo unit - was getting quite a bit of interference / ripple in the picture - looked like AC ripple was leaking in to the DC voltage. The caps were fine in both systems so had a look at the PSUs - they have some sort of security screw but a SNES gamebit screwdriver works fine to open them up.

    PSU 1

    1.jpg2.jpg

    PSU 2

    3.jpg4.jpg5.jpg

    PSU 3 - this one is from my other MD - a HDG Model 1 - seeing the pattern decided to pop this one open as well

    6.jpg7.jpg

    Some observations:
    - failed caps on all three PSUs (no sh*t ), tops still flat but leaking fluid from the bottom
    - crappy 'no real brand' caps used in all PSUs vs Rubycon caps used on the hardware
    - 85C rated caps used

    Just ordered some Panasonic low ESR 3300uF 16V 105C rated caps to replace.
    Last edited by MtothaJ; 05-26-2019 at 12:41 PM.
    Regards, MtothaJ

  2. #2
    Yuri's Aerobics Instructor
    greedostick's Avatar
    Join Date
    Aug 2003
    Location
    You have to break an egg, if you are to know what is inside.

    Posts
    4,121
    screw all that. Just buy a Sega Trio PSU from www.Retrogamecave.com

  3. #3
    Mickey's Coach

    Join Date
    Apr 2013
    Location
    PL

    Posts
    749
    The're pretty expensive and from what I can see shipping is US + Canada only at this time.
    Do you have any pics of the Trio internals?
    Regards, MtothaJ

  4. #4
    Formerly Raz_Hoe.
    RAZO's Avatar
    Join Date
    Dec 2006
    Location
    New Jersey

    Posts
    6,707
    I still love my original Genny psu's. Use them for my Super Sd, Genny, Famicom, SFC, even some newer Neo Aes consoles I have. Just dont care for these flimsy over priced after market psus.

  5. #5
    We have purposely
    trained him wrong
    ...as a joke.
    ChuChu Flamingo's Avatar
    Join Date
    Nov 2010
    Location
    US

    Posts
    2,104
    The trio is good but if you have og power supplies not much merit to upgrade. These bricks barely use any watts. Replacing the one capacitor if leaking or blown is super easy and cheap.

    Only reason to upgrade to a trio is if you don't have any psu at all or to maybe feel slightly safer about your giant daisy electrical fire death trap psus.

    Edit: opened mine up and it has stuff on the bottom of the capacitor. Might be glue but I doubt it. The black capacitor appearance is a little iffy too. I will order some capacitors.
    Last edited by ChuChu Flamingo; 05-28-2019 at 02:41 AM.


    he spends hundreds on scarves, of course he's a fag and then ChuChu Flamingo preserved the aftermath in a plastic case making sure it wasn't exposed to unstable air
    You're just upset that you're too goddam stupid to understand the games and whiff infinites.
    Nintendo 64 Pikachu Edition Serial #NS294668665 Nintendo 64 "Funtastic Series" Jungle Green Serial #NS28721865

  6. #6
    SouthTown StreetSweeper
    sparksterz's Avatar
    Join Date
    May 2013
    Location
    Rochester, NY

    Posts
    562
    Thanks for the PSA. I have a few sitting around and just pulled them after setting up my Mega SG

  7. #7
    Mickey's Coach

    Join Date
    Apr 2013
    Location
    PL

    Posts
    749
    Caps arrived today so replaced the caps in the 3 PSUs:

    20190528_175247.jpg

    Happy to report that the ripple / interference is now gone.

    As for the Trio I see little point now that the caps have been replaced. That and its a switching PSU while the OG ones are linear / coil ones.

    As for the caps - the stock garbage ones are 2.5cm in height. The replacement Panasonic ones I ordered are 3.5cm - that height is still entirely fine - PSU cover closes fine on all 3 PSU's without the top making any contact with the shell - but that is as high as you can go, if e.g. you want to upgrade the caps to 25V ones instead of the standard 16V choose ones which are bigger in diameter rather than higher as you will have clearance issues.
    Regards, MtothaJ

  8. #8
    Mickey's Coach

    Join Date
    Apr 2013
    Location
    PL

    Posts
    749
    Quote Originally Posted by ChuChu Flamingo View Post
    Edit: opened mine up and it has stuff on the bottom of the capacitor. Might be glue but I doubt it. The black capacitor appearance is a little iffy too. I will order some capacitors.
    Its definitely the electrolytic fluid leaking. Its kind of weird that these caps vent from the bottom and not from the top but whatever - at least the soldering / desoldering and replacement is extremely easy to do so at least that's a plus.
    Regards, MtothaJ

  9. #9
    . wuemura's Avatar
    Join Date
    Jun 2019
    Location
    Brazil

    Posts
    7
    Electrolytic capacitors has a short life span, around 2 years if you don't use them (including shelf life) or 10 years (15 years max) in use, to avoid further problems they all must be replaced, the sooner the better. If you are gonna do a recap, it is better to use solid polymer types instead, I've posted some details here.

    If you don't want to have any problems with your old consoles avoid the use of any modern switching power supply on them. SPS's uses a "special" type of electrolytic capacitors with low internal resistance or low ESR.

    Old electronic consoles uses standard type capacitors, the switching from the SPS plus the medium/high ESR causes the capacitors to heat up (ohms law), to build up a pressure inside and they will fail or leak eventually.

    To use a SPS on a old console all people has to do is to recap the board with low ESR caps or replace them with dry polymer type capacitors.
    Friends don't let friends play MAME

  10. #10
    Haomaru's Blade Shiner
    dragonpt's Avatar
    Join Date
    Oct 2008
    Location
    ネオジオCO、ポルトガル

    Posts
    839
    Thanks for the hint...

    I guess I must check my MD1/MD2/nomad PSU's...
    ...
    Hyper Neo Geo 64 / Neo Geo CD - Top Loader / Neo Geo Poket Color/ Neo MVS - MV1FZ / 1B / 4F

  11. #11
    Chang's Combo Meal #4
    MKL's Avatar
    Join Date
    Mar 2002
    Location
    -

    Posts
    3,679
    That's just glue to hold the cap in place.
    Last edited by MKL; 06-14-2019 at 05:29 AM.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •