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Hello..! My second synth, a roland jx-305 crashed and after restart it only shows black blocks in the upper line and the beat les is on lighting orange color... It wont work after a lot of restarts and i have changed the 9volt power supply... Does anybody know how to solve this problem or have a service manual of this synth because i cant find it on the net...

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Try a "factory reset" on the unit. Make sure you hold the buttons till unit confirms the reset.

Posted on Oct 04, 2010

  • 6 more comments 
  • Theo Ntizas Oct 04, 2010

    I mean total crash.The synth dont boot up or play anything...

  • Fred Yearian Oct 04, 2010

    I assume you replaced the adapter with an EXACT replacement unit. I have heard of some having problems trying to use substitute adapters on some of these. You need a 9 Volt DC with 450Ma or more rating of the PROPER polarity (shell and pin)

    I have service manual and it is 3.7 Mb which may be too big for emailing, but send me you email and I will try. Unless you have an equiped electronics shop you will probably not be able to make any progress.

  • Theo Ntizas Oct 05, 2010

    my email is
    hotmail gets 10 mb of files..!
    If you cant send it can you plz upload it to rs or hotfile and send me the link?!

  • zhao_rule Oct 20, 2010

    hello guys, i have a jx-305 as well. i lost my adapter when i moved and i bought an aftermarket one from 'the source'. its 9v but 800mA. when i plugged the synthesizer, it went on with some displays on the screen then suddenly some zeros( 0000000) appeared and all i have is an ORANGE light on the "BEAT".

    i hope you guys can help. if you guys can help me with the manuals/instructions youy can send it to

    thank you kindly

  • shane
    shane Oct 19, 2013

    Hi there i have the same problem. Did u get your JX305 fixed?

  • Theo Ntizas Oct 20, 2013

    I haven't fixed mine, tis most probably the cpu... :/

  • shane
    shane Oct 20, 2013

    HMmmm it only just happend to me recently...Did u try to factory reset the unit? i found this online

  • shane
    shane Oct 20, 2013



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