i just had to fix a trinity with the same problem
if you just plugged in the left/mono output to a mixer it worked fine
if you just plugged the right output to a mixer the right channel would work
but if you plugged both outputs the right output was lost
i did some continuity tests i tested pin 1 rin and tested the rout with the dual log pot at max and i had no continuity
did the same for the lin and l out and had continuity so the dual log pot was shot and i had no continuity at all on the right channel
i tested a spare pot and when testing the legs with the pot at full i got continuity like you should
i desoldered the part and tested again was no continuity at all on the right channel
i replaced the pot and it worked correctly as it should
how to solve right output issue on Trinity
Moderators: Sharp, X-Trade, Pepperpotty, karmathanever
also when doing the repair work check the solder pads for the cracks
i have had to re-solder several output pads for the phono sockets and also on the headphone this is because they rely on the solder connection as the mechanical connection which can crack due to excessive pressure and wait by plugging in and out of the sockets
this is a design flaw as other manufacturers also add fixing nuts to the metal brackets so the mechanical stress is taken by the bracket and not the solder connections
and if you are going to do a job properly do it rite using superglue or rubber or duct tape to fix things is stupid and if you don't know what your doing don't touch it
for fixing use tie raps
for replacement felt korg has replacements all that is needed is double sided sticky tape and tape it on top of old felt as this is so compressed any way
this is the same for all yams and korgs key-beds that use Yamaha key-beds
later keyboards like the m50 m3 kronos use fatar key-beds
so the proper fix for the output problem is
1 test socket solder pads of the phono sockets on both the outputs on the back and the head phone socket at the front
2 if cracked re-solder but i would re-flow as matter of course as a visual inspection you might not see it and continuity test will ring as there is contact but bad contact
3 use DE-oxite to clean the pins of the connectors on both the plugs and sockets this will give you a clean connection no extra resistance due to corrosion
4 test the socket for the volume fader control there is a r-in and a r-out
and a l-in and l-out these go to the volume dual audio taper pot move the slider to full volume position now get your continuity tester and place the +/- probes on r-in and r-out you should get continuity if not then the fader is bust
do the same for l-in and l-out if your getting continuity there what seems to be happening is the dual log pot is braking down and is cross talking on the channels so that when you put a plug in the left channel it out puts audio and if you swap it to the right channel you also get audio out the right channel
but when you plug both in the right channel audio is taken to earth and all you are getting is left audio
this is what has been stumping people because when only a mono plug is plugged in either left or right there is audio so you think that the machine is outputting properly when its not
you need to de-solder old pot and replace once replaced do the continuity checks again at full volume and you will get continuity from l-in and l-out and r-in and r-out
the pot replacement korg uk does not do them any more as its a stopped product
but original is an alps and alps make the same item but a new part number
you need a dual pot slider 603k-10kx2 alps they sell these at rs components
i have been a keyboard synth tech for 25 years and have been working on many synths and samplers
i do upgrades and design circuits and i run a synth repair shop in uk
my specialty is korgs and Ensoniqs and Yamaha and Roland,Emu
do lots of replacement vfd and oled and led displays
as well as doing the korg dss1 upgrade and upgrades for the emax1 samplers
and designing new pcm cards for wavestation and m1/t1 series which will have new pcm data for those that don't own a t1 series synth
i have had to re-solder several output pads for the phono sockets and also on the headphone this is because they rely on the solder connection as the mechanical connection which can crack due to excessive pressure and wait by plugging in and out of the sockets
this is a design flaw as other manufacturers also add fixing nuts to the metal brackets so the mechanical stress is taken by the bracket and not the solder connections
and if you are going to do a job properly do it rite using superglue or rubber or duct tape to fix things is stupid and if you don't know what your doing don't touch it
for fixing use tie raps
for replacement felt korg has replacements all that is needed is double sided sticky tape and tape it on top of old felt as this is so compressed any way
this is the same for all yams and korgs key-beds that use Yamaha key-beds
later keyboards like the m50 m3 kronos use fatar key-beds
so the proper fix for the output problem is
1 test socket solder pads of the phono sockets on both the outputs on the back and the head phone socket at the front
2 if cracked re-solder but i would re-flow as matter of course as a visual inspection you might not see it and continuity test will ring as there is contact but bad contact
3 use DE-oxite to clean the pins of the connectors on both the plugs and sockets this will give you a clean connection no extra resistance due to corrosion
4 test the socket for the volume fader control there is a r-in and a r-out
and a l-in and l-out these go to the volume dual audio taper pot move the slider to full volume position now get your continuity tester and place the +/- probes on r-in and r-out you should get continuity if not then the fader is bust
do the same for l-in and l-out if your getting continuity there what seems to be happening is the dual log pot is braking down and is cross talking on the channels so that when you put a plug in the left channel it out puts audio and if you swap it to the right channel you also get audio out the right channel
but when you plug both in the right channel audio is taken to earth and all you are getting is left audio
this is what has been stumping people because when only a mono plug is plugged in either left or right there is audio so you think that the machine is outputting properly when its not
you need to de-solder old pot and replace once replaced do the continuity checks again at full volume and you will get continuity from l-in and l-out and r-in and r-out
the pot replacement korg uk does not do them any more as its a stopped product
but original is an alps and alps make the same item but a new part number
you need a dual pot slider 603k-10kx2 alps they sell these at rs components
i have been a keyboard synth tech for 25 years and have been working on many synths and samplers
i do upgrades and design circuits and i run a synth repair shop in uk
my specialty is korgs and Ensoniqs and Yamaha and Roland,Emu
do lots of replacement vfd and oled and led displays
as well as doing the korg dss1 upgrade and upgrades for the emax1 samplers
and designing new pcm cards for wavestation and m1/t1 series which will have new pcm data for those that don't own a t1 series synth