Hi, I discovered that the attachment did not go through with the email. So I uploaded the wiring diagram to the files section of the list. http://launch.groups.yahoo.com/group/PolySix/files/PS6_KEY.PDF Johannes On 30.07.12 20:56, Johannes Hausensteiner wrote: > Hi, > > The Polysix scans 8x8. So 9 keys failing would be rather odd. > But from G1 downwards it's only 8 keys... So we're back in the game. > The low eight keys are read through D0 (see attachment). > Check for continuity from the Kyboard PCB to MIDI Module/IC5/pin4. > > Good luck, > > Johannes > > > On 29.07.12 00:27, Peter M\ufffdrck wrote: >> Hi, >> >> Speculations ahead. Skip to next part if not interested :) >> There are 16 wires going to the keyboard. >> I can't from the schematics tell if the keyboard is scanned as 8x8 or 7x9. >> 8x8 would probably be more "natural" as it allows the P-pins to set "row" and the DB-pins to read column, so to speak. >> It requires 8 partial scans, scanning 8 keys at a time. Maximum number of keys 64. >> On the other hand, 7x9 might be faster since it only requires 7 scans, scanning 9 keys at a time while still allowing a maximum of 63 keys. >> Since we only have 61 keys, and you say 9 keys are dead, I would guess it scans as 7x9. >> >> Next part: >> I suspect one wire to the keyboard is open circuit somewhere, or perhaps one of the diodes on the keyboard board? >> I don't remember how the diodes are connected on the keyboard and I'm too tired to figure it out :) >> Do continuity testing from the solder side of the keyboard connector to where the cable is soldered onto the keyboard board. >> But first, wiggle the keyboard connector a bit and then press it down firmly and see if that helps. >> It's probably attached with some glue but .. well.. heh.. >> There are no components between the keyboard and the keyboard scanner controller, though there are other things on those lines as well that might interfere if fried, though I still suspect it's just a mechanical problem with the connector or some solder joint. >> >> BR, >> Peter >> >> >> >> ----- Original Message ----- >> From: feline1973 >> To: PolySix@yahoogroups.com >> Sent: Saturday, July 28, 2012 11:33 PM >> Subject: [PolySix] dead keys :( >> >> >> >> My Polysix has developed a fault with its bottom 9 keys (G downwards) - >> first they started intermittantly failing to trigger when pressed, >> then they started doing odd things like being silent when held down together...... and now they're all just dead. >> >> I dismanted the keyboard assembly and cleaned the conductive studs and contacts on the circuit board - didn't help. I doubt very much they're the problem, as swapping different rubber stud-holders around doesn't change things. >> I'm wondering if the multiway cable between the keyboard and voice board could be the culprit? Maybe just one of those yellow wires is dud? >> I can't even get it out to swap it, the keyboard end is stuck in its socket. >> >> Any suggestions? >> >> (Oh, and it all plays perfectly if trigger exterenally via MIDI - I have Johannes Hausensteiner's retrofit) >> >> David >> >> >> >> >> >> [Non-text portions of this message have been removed] >> >> >> >> ------------------------------------ >> >> Yahoo! Groups Links >> >> >> >> > > > [Non-text portions of this message have been removed] > > > > ------------------------------------ > > Yahoo! Groups Links > > > >
Message
Re: [PolySix] dead keys :(
2012-07-30 by Johannes Hausensteiner