Roland JV-90 Repair

Customer states patch data corruption while in use which lead to weird sound all over the place.

Roland SR-JV80 Re-writable ROM Card with ESP32

For user manual and purchasing please visit: https://www.ddzheng.cc/?page_id=666 Final Update Open-source Hardware Hardware Repo: https://github.com/connorzheng97/srjv Firmware Repo: https://github.com/connorzheng97/srjv-fw Production Test For production test I have a contractor made a test fixture which probe the production header footprint from top side. The card is placed upside down in the fixture, a small board with mating expansion ... Read More

Roland XP-80 LCD Replacement

Final modification for my XP-80, and you can do this as well. Should apply to JV-2080 and XV-5080 as well.

Tektronix DPO71254B Repair

There is a DPO71254B at my workplace that has been abandoned for quite a while. I repaired it so that we can use it to debug (no cal though)

Oscilloscope Measurement Artifacts 1

In this article I present some aspects that distort electrical signal measurement result, with focus on what happens in the scope itself after the signal has entered an oscilloscope.

Repair SONY DSC-P93

Repair a SONY DSC-P93 that has stuttering OVF zoom and an error message