Access Virus Indigo
This time, a rather unusual guest arrived at my workshop — the Access Virus Indigo. According to the owner, the instrument was completely dead and wouldn’t power on at all — basically a brick. During the initial inspection, it turned out that the synth was actually starting the bootloader, but getting stuck in an endless reset loop without even turning on the LCD backlight, which made it seem completely unresponsive to the power switch (it was extremely difficult to notice that anything was appearing on the display at all). Either way, the synthesizer would briefly show the operating system version, reset itself, and repeat the cycle endlessly.
It quickly became clear that the cause of this behavior was the rather complex power supply section built around a DC/DC converter and several voltage regulators. Every power rail showed significant voltage fluctuations and spikes reaching up to 800mV.
The repair included replacing all electrolytic and tantalum capacitors (33 pieces in total), fixing the LCD backlight switching circuit by installing two resistors, replacing the faulty Master Volume potentiometer, reflowing several integrated circuits, and thoroughly cleaning all knobs as well as the device’s front panel. After these procedures, the instrument returned to full working condition.
That said, looking at the original power supply design, I can’t say I’m particularly impressed by the engineering craftsmanship. They used an off-the-shelf 12V/1.25A power supply module and rather shamelessly mounted it inside the unit without even attempting a professional integration — relying instead on a basic coaxial power connector. Considering the musical value of the instrument, its price, and the reputation of the brand, this is hardly something the manufacturer should be proud of.
The same goes for the keyboard assembly — it feels like the cheapest and flimsiest module possible, probably weighing no more than 200 grams. On the positive side, however, I have to give credit for the excellent serviceability of the instrument and the multilayer PCB design, which likely contributes to better audio quality.
