Boss CE-3 Restoration Part 4 (Final): Troubleshooting and Revival

Welcome to the final entry of the Boss CE-3 restoration project.

After replacing the capacitors and trimmers, I was left with a pedal that passed signal but produced no chorus. The "Last Mile" is often where the most difficult problems hide.

The objectives were:

1. Replace oxidized trimmer (Done)

2. Audio Grade Recapping (Done)

3. ACA to PSA Conversion (Done?)

Part 1 Part 2 Part 3

Part 4: The Diagnosis

I began by tracing the circuit with a multimeter.

This vintage PCB is translucent. By shining a flashlight from the component side, I could easily trace the tracks on the solder side to check for continuity. I discovered that the voltage across the board was generally lower than the schematic specified.

First, I checked the power entry point. I found an intermittent connection at the DC jack soldering points. I reflowed the solder, ensuring a solid connection. This helped, but the chorus was still absent.

To troubleshoot further, I needed to check voltage propagation while the unit was active.

I used a loop pedal to feed a constant guitar signal into the CE-3. This allowed me to work hands-free.

Note: I used a "jumper method" to manually bridge voltage points to test continuity. This was done in a low-voltage (9V-12V) environment. I do not recommend this technique for high-voltage tube amplifiers or AC equipment, where risk of shock is lethal.

Through this process, I discovered the BBD (Bucket Brigade Device) chips were starved of voltage.

The Resolution:

Full article on Patreon @yewplaysmusic