JUNO-106 TEST PROCEDURE
#ENTERING TEST MODE & INITIAL SETTINGS
-Hold KEY TRANSPOSE, turn on your JUNO-106 and release KEY TRANSPOSE.
*The display should now show '-_'. This means that your JUNO-106 is now in
'test mode'.
-Turn on POLY 1 and POLY 2.
*Your JUNO-106 is now in 'rotary' mode. The display shows which voice is
playing.
-Do following settings:
-RANGE to '8
-PWM: man
-SQR & SAW: off
-VCA switch to ENV
-PORTAMENTO: off
-All sliders to 0 except:
-VCF FREQ: 10
-KYBD: 10
-VCA: +5
-D: 10
-S: 5
-R: 2,5
#NOISE TEST:
-Set NOISE to 10.
-Play a few notes.
*You should hear noise from all voices.
*If you hear constant noise without playing a key, then you have one or more
hanging VCA's.
*If you hear no noise at all, then you have a dead noise generator. There is
only one noise generator.
*If you have one or more voices without noise, then the VCA for that voice is
dead.
-Set NOISE back to 0.
#WAVE FORM TEST:
-Turn on SQUARE.
-Play a few notes while playing with the PWM slider.
*You should hear sound from all voices and pwm should work too.
-Turn off SQUARE and turn on SAW.
-Play a few notes.
*You should hear sound from all voices.
-Turn off SAW and set SUB to 10:
-Play a few notes.
*You should hear sound from all voices.
*If any of the above failed for a voice (except the ones that already failed in
the above noise test), then that voice has a broken wave generator chip.
*If you have a hanging note, then play some different notes with any wave form.
When the pitch of the hanging note changes, then the voice you last played has
a broken VCA.
-Set SUB back to 0.
#FILTER TEST:
-Make sure SQUARE, SAW, SUB and NOISE are off.
-Set FREQ to 5.
-Set RES to 10.
-Play a few notes.
*You should hear sound from all voices.
*When playing 6 times the same note, you should hear 6 time 'almost' the same
note.
*If you hear no sound from a voice or the pitch is 'way' off, then that voice
has a broken VCF. If the pitch is a little off, then your JUNO-106 needs
adjustment.
-Now play a bit with different RES settings. The sound should disappear for all
voices at about the same RES level. If a voice still plays with a RES level far
below the ones where the other voices stop, it means that this voice's feedback
VCA is hanging.
#CONCLUSION:
-WAVE-GENERATOR chips are the MC5534A IC. There are 3 in your JUNO-106. VOICE
1&2, 3&4 and 5&6 each share one. Except for the really old ones: These have 2
chips glued together, but these 2 can also be replace by a MC5534A. They are
still available from ROLAND.
-VCF and VCA are in one combo chip: the A1QH80017A IC or the A1QH800170 IC for
the really old ones. Identified by 80017A or 800170 stamp on the chip. These are
really crap chips and are no longer available. There are 6 of them in your
JUNO-106. One for each voice. Replace them with my D80017 modules. They sound
exactly the same and are a lot more reliable than the original ones.