Hi all, there are three IC on the panel boards (369 and 370) one 4556D which is an oamp as i found out this one is for the volume knob i think...and two 14051. These are multiplexers..so they could be the reason for the strange behavior...I'll check them...as soon as i get the osciloscope..Does anyone know where to get the 14051 chaep in germany ??? See ya all Gregor So long > > The 4xxx IC family tends to go bad when old > > > --- In PolySix@yahoogroups.com, "Gregor Quade" <u3dreal@y...> wrote: > > > > Thanks alot Gil, > > > > I already checked all the traces on the board which might got > > affected by the batteryleak. So far they are all working fine. > > > > The Tip with the logic IC on the frontpanel is very good. > > I'll try that. I also thought of that. but i wasn't sure. > > > > Update to come soon. > > > > Still if anybody has advice i would appreciate. > > > > thanks to all. > > > > Gregor > > > > > > > Hello all; > > > > > > > > I bought a polysix in rather bad condition... > > > > > > > > I did the batteryreplacements and checked to circuits...they > seem to > > > > be OK for both sides of teh PCB > > > > > > Make sure it didn't experienced any battery leakage. You can look > for > > > green rust on the PBCs and the components on both the computer > board > > > and the one that is place above it, attached to the panel. If it > did, > > > you'll have to rewire some traced and replace some parts that may > got > > > defected by the acid... > > > > > > > > > > ...many things were still wrong then I replaced the IC31...and > the > > > octave > > > > knob and the sub osc were working again. > > > > > > > > The Controls are better now but still don't work correctly.. > > > > > > > > the MG....Delay doesn't work at all and Level gets controlled > by the > > > > VCO PW/PWM knob...? the EG doesn't seem to work either.. > > > > only the sustain can be controlled via the LFO resonance knob.. > > > > > > I had similar problem on my Trident, which I solved by replacing > a > > > few logic ICs on the panels, which were directly related with the > > > knobs that didn't work properly. In on case I found that a > technician > > > who tried to fix the machine, has placed on IC one of the ICs in > > > reverse !! > > > > > > > > > > > > > > all the other things like the preset section / loading saving > > > progamms > > > > or even sending and receiving banks form external casset > recorder > > > > works....!!!!! > > > > > > > > > > So the computer board seems to be ok. > > > > > > > when i try to do the testing procedure with the 56k > resistor...the > > > > following happens.....when i turn the trim clockwise there is a > > > point > > > > where is jumps from bankA prog1 to all eight > proglights.....this > > > doesn't > > > > happen > > > > for me the two first ( prog 1+2) don' light...sometimes > > > > its only the first one which doesn't light... > > > > when i remove the resistor it switches back to prog1 bankA > > > > > > > > > > Normal ?.... > > > > > > > I have no idea what could be wrong...could it be IC30 or even > the > > > > processor ?? Did you have something simlar ? > > > > > > > > > > I would check/replace the suspective ICs on the panel board first. > > > > > >
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Re: Polysix wiered behaviour
2005-12-14 by Gregor Quade
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