My customer Aaron, was fed up with the poorly back-lit display on his black re-release SP-1200, and wanted to have the Noritake CU16025-UW6J display from Digi-Key fitted. They are expensive, and being glass, fragile; but they are bright and clear so a good upgrade.
Unfortunately the display is smaller than the aperture in the circuit board, and an attempt at notching out mountings was made to no avail. The display is also thicker than the original and spacers are needed to move it down. After several attempts I decided to make 3mm deep adapters on the 3D printer, and this gave me a stable mounting that I could squarely align the display on. You also have to make an adapter cable as the pins are reversed.
The next issue was that the display character area was smaller than the original, and it did not have a bezel. This looked bad, and the glass was exposed. Thankfully I had an 80×2 line lcd filter lens in my parts bin and could cut that to size. It covered the ugliness nicely, and protected the display. Aaron was happy! Final job was to open all switches and drum pads to clean them and restore playability.
Emu Emulator II
This one had a bad power supply, and the customer had been trying to fit more modern replacements. Re-soldering cold solder joints bought the base power supply back to life on the bench, and when fitted to the Emulator the root issue was shown to be a shorted tantalum capacitor on the input to the -15v regulator. The harness was in a sorry state where it connected to the power supply, and a new connector was fitted. Continue reading
This was purchased by the customer some time ago, and he had stopped using it due to boot problems. It had sat in storage for some time and gradually degraded. It was a missing large touch-pad button, plus the boot diskette had been lost. Without the diskette there was no way of finding out what else is required, and the customer went off to find one.
A boot diskette was finally sourced, and after many attempts it finally booted. The boot issue needed to be addressed, and it showed a need for pad button switch cleaning. The LCD back-light was also out. Continue reading
This E-Mu Drumulator was blowing fuses due to a shorted tantalum capacitor in the power supply. The power supply held the CPU in reset following this, and a CA3086 transistor array was replaced to resolve this, along with the related FCO from EMU. One switch was missing and replaced, the switches were cleaned, OS 3.0 was installed.
via This Old Synth – Vintage Analog Synthesizer Repair Portfolio Page.