Yamaha electone mc-600 indication problems

[shiny6905]

Hi. can someone please help. my yamaha has got a problem with the indications. none of the LED's light up. i have had the thing open and checked everything i can think of but cant find anything wrong. does anyone have any idea how this can be fixed?

[JanneK_69]

Just fixed similar problem in my organ: lift keyboard and check 4700 uF capacitor + 3.3 ohm resistor down at left side where colorful wires go. Mine had capacitor shorted and resistor broken.

[[email protected]]

HI,HAVE A SIMILAR PROBLEM,
HALF THE LIGHTS ARE FLASHING,ON SWITCH ON,
STARTED SUDDENLY
SUSPECT POWER SUPPLY TRIPP ON OVERLOAD ?
ANY HELP ?

[horst1ish]

while checking voltages-found DM-1 board and MA board supply b+ was at 3.5 v and
oscillating,while the voltage for bu-c board was 4.5 steady.
SECTION LOCATED LEFT UNDER THE KEYBOARD PANEL.
the 2500mfd-35v and the diode where ok.(WAS REPORTED TO BE THE PROBLEM)
still working on it.
[email protected]
horst

[Guest]

TRACED THE OSCILLATING PROBLEM TO THE POWER SUPPLY.
CIRCUIT 5 VOLT IC IC 3052 SUSPECT.BUT IT IS ALMOST IMPOSSIBLE TO GET THE
POWER SUPPLY BOX OUT OF THE ORGAN,DUE TO THE WHITE WIREING CONNECTION
ON TOP OF THE CICUIT BOARD.
THIS REALLI IS A DESIGN PROBLEM.
HORST IN OAK FLATS NSW 2529
[email protected]

[Guest]

NO LUCK-remuved the power supply,but found no problems,on resistors,diodes,transistors,all are operatind within speck.
voltages are as per diaghram.
it looks like the problem is between DM1 and MA board.
bummer,more time of checking involved.
horst

[horst strecker]

NEED HELP,NO ONE ON THIS SIDE HAS ANY SUGGESTIONS ?
FOUND A SECOND HAND MC-600 FOR $450 IN SOUTH AUSTRALIA.
BUT THE TRANSPORT COAST ARE A KILLER.

HORST IN AUSTRALIA

[horst]

IT MORE AND MORE LOOKS ,THAT THE POWER SUPPLY IS THE PROBLEM
IC 501 NEGATIVE VOLTAGE IS DOWN TO 0.13 VOLT,
IT SCHOULD BE -5.0 VOLT.
APPIERS T O UPSET IC 503, +14.8/-15.11 VOLT.
WILL REPLACE THE IC ,THE CAPCITORS AND DIODES.
IC SI 3052V - +5VOLT 2A 50W
[email protected]
HAD ADVICE FROM [email protected]

[horst]

REPAIRED THE ORGAN ,FOUND THE PROBLEM,READ THE THE LAST PAGE OF THE SERVICE MANUAL, THE PROBLEM WAS THE RESET SWITCH ON THE TOP RIGHT HAND SIDE OF THE KEYBOARD PANEL.THE FIRST SWITCH BUTTON ACTS AS A RESET IN CASE YOU CONNECT A NEW SOURCE TO THE LOWER RIGHT HAND ORGAN INPUTS.IT IS BETTER TO SWITCH THE ORGAN
OF FIRST.THAN PLUG EXTERNAL ITEMS IN.
THAT TOOK ME 2 WEEKS TO WORK OUT.I HAD NO HELP HER IN AUSTRALIA,NOBODY WANTS TO
REPAIR ORGANS,THIS IS WAY YOU CAN BUY SECOND HAND ELECTRONIC ORGANS ON E BAY
FOR LESS THAN $250.
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