Very grubby Roland D-70 with many keys electrically not working and a couple mechanically "stuck" as the adhesive holding the weights into the keys appears to have melted. Kudos to The Music Tech Guy (Jon) for coming to the rescue with factory restore card as memory reload over MIDI was not playing ball...
Hummm. Roland JX-3P with some issues, most worrying but not at all serious was a VERY noisy transformer, gave you a strong sense you might be electrocuted if you turned it on. Not the case, transformer is a stack of thin metal plates glued together and wrapped with copper wire, over time the glue can dry and the plates can move, at 50Hz. ... No multi-tap available so one big replaced with two small, just the right volts and amps and blissful silence!
St James Church, Itchenor - large but not happy, with just one key making no sound. Screwdriver and a good clean, sorted!
Woodwork?! A pair of Sequential Pro-One's that now look like Prophet One's! I was banished from woodwork at School.. Long time ago...
Roland Jupiter 6 - wonderful with 12 VCOS based on legendary CEM3340 capable of producing three waveforms simultaneously. This one has been gigged and I suspect died and was left to rot in a damp cellar, multiple problems - all 3 CPU chips, multiplexers, one of the VCOs and lots of new sliders. Always a battery...
Roland JX-8P again, this one very sick... Kinda worked, only one DCO so half the sounds didn't work, most of the pushbuttons and sliders and the usual flat battery. Unusually, the problem (apart from worn switches was a microprocessor concerned with RAM and I/O (IC 34). One of the last of the old semi-analogues.
Very Cool Oberheim Matrix 1000 rack mount is a Matrix 6 with 1000 patches stored in an EPROM, at the heart, the world infamous CEM 3396. Each of its 6 voices have two DCO's (digitally controlled analog oscillator), a low pass filter, 2 VCA's, 3 envelope gens, 2 LFO's, and 2 ramp gens. This one arrived with 1.1.1 showing in the display (dead battery) but after upgrade to latest firmware (1.2) and the addition of a new patch EPROM (to deal with corruption in the old AND broken wires linking control panel and main board, still no sound. Further investigation revealed a digitally controlled analogue switch fault (multiplexer). Sounding as good as new!
Break from the norm - MASSIVE Panasonic Ramsa WR-DA7 Digital Mixer with poorly power supply, overload had blow soldered in fuses, rare to see hard wired fuses which I can only assume exist as a last resort to stop the device catching fire. They worked and so did the desk once all it's issues were solved.
Surprisingly valuable and well loved Viscount Cantorum II organ, amplifier problem, no circuit diagrams available, back to basics...
Super interesting to be asked to repair a Gulbransen 650L organ - 1970's massive beastie with much to sort out. I can imagine one rising from the middle of a stage in a cloud of dry ice! Love the Leslie Tremlo (https://en.wikipedia.org/wiki/Leslie_speaker) This made in the USA and weighing in at what must be getting on for 100kgs! Fixed!
Lexicon MPX-1 "Multi-Effects" processor, DOA and quickly brought back to life with a new power supply. The old (burnt out) one was apparently not well designed and this is a common problem.
Armon Selmer Electric Portable Piano c. 1975. Loud Humm and only one tone, c4#... Combined power supply and amplifier transistor faults, dirty key contacts and switches. Solved!
Cheetah MS-6 6 note poly, true analogue using CEM 3396 to generate tones, also used by Oberheim's Matrix 6 and Matrix 1000. This one prone to that old favourite, the acid leak onto the mother board. Also a trimmer pot broken off.. All repaired, good as new!
Dirty old man! Well this ARP Axxe looked like it had come from the scrap yard - filthy mechanically and electronically. Also making no sound other than a anguished howl of pain. Stripped down, soapy water for the case, keys and mechanicals, electronics chemically cleaned. Reassembled good as new! (Well, apart from all the slider caps missing)!
~1986 vintage Yamaha V50 Sythesizer / Sequencer with hot chocolate I think spilt on the keyboard. Cleaned, tested and re-set - all working again!
First time to see a German made Virus access "Simulated Analogue Synthesizer". This one with display showing nothing helpful, turned out to simply need a new backup battery and unusually, no soldering iron necessary!
Well loved and used Kurzweil Midi Controller full size weighted keyboard with velocity sense and aftertouch. Following accidental water spill, velocity sense problem on a few keys. Solved by stripping the unit, cleaning key contacts and reassembling.
Super FAT sounding Sequential Pro-One in for tune up and clean. Screws missing, wobbly mod wheel, no power... Cleaned, repaired and tuned up - sounds great!
Wow what an amazing keyboard! Roland A-90 power supply problem solved (dry joints on voltage regulators which get hot!), VE-JV1E expansion board added providing massive range of sounds with dynamic control of 4 internal and 4 midi devices!
Thanks to Andertons Music in Guildford for your recommendation to John who needed a new display in his Korg 01/W FD @andertonsmusic / andertons.co.uk
Very dusty KorgPoly-800 arrives for battery upgrade (to non-solder version) plus circuitbenders polybeast upgrade (find here)
Roland SH-2 110 volt Japanese import, power supply transformer replaced to suit 240 volt UK mains
(No job too small!) Casio VL-Tone power supply problem quickly diagnosed and repaired, noisy sliders cleaned up!
Roland Juno 6 for Kenton MIDI upgrade. Internal before & back panel after:
Roland TR-606 Cymbal and Hi-Hat intermittent fault - interior and exterior:
Roland Jupiter 8 keyboard repair and service. Sliders and pots cleaned to stop them being noisy, broken key replaced:
RMI 8 Channel A/D Converter intermittent power supply fault - MOSFET internal breakdown, heatsink has got so hot it has distorted the circuit shield. Replaced MOSFET, power on self test good (below):
Korg Poly-61 ROM Batter Replacement and MIDI kit installation:
Three rubber key switches not working, all cleaned up and now good as new.
Roland JP-8080 - request from client to replace all value selection potentiometers (knobs), this would be very time consuming. Turns out all that was needed was cleaning, solved for less than a fraction of what was expected! Backup battery also replaced.