Deinyon's Blog Place

If you've just got your hands on a pre-owned EWI3020m, perhaps from a junk auction, and you switch it on for the first time to hear either nothing at all or perhaps weird bleeps, bloops and funky Atari 2600 special effects in the best of cases, then your problem is likely a dead non-volatile-memory battery . De-Lidded EWI 3020m with Battery Mod Why? When the battery-backed memory loses its power completely, it loses its ability to retain information once system power is switched off. When the power is switched back on, the values of each bit in memory are amplified to restore them to normal logic levels. Having been unpowered for some time, the memory is storing only random noise, so all user data is now corrupted, nonsensical, and out of the typical ranges (hit the MIDI  button on the front panel and check out the RX and TX channel settings - nominal values are numbers 1-16, but corrupted values will exceed far beyond that range and even roll over into special charact...

The EWI3020m's "non-volatile" memory battery is soldered directly to the main PCB, which means you have to take the whole PCB out in order to desolder and replace it. I took my newly acquired EWI3020m apart a few days ago to replace the hardwired battery with a coin-cell battery holder. Every one of the boards are single-sided Phenolic Paper PCBs populated solely with through-hole components and even jumper wires. You can see in the pictures that even some of the ICs (the CEM3374 VCO and EPROM for example) are socketed! Certainly makes repairs a happier experience. Here are a few pictures of the disassembly and the main PCB itself; apologies for not having a suitable scanner! Main PCB Images EWI3020m Main PCB EWI3020m Main PCB (traces) Composited view of the component-side and trace side Re-Assembled with Battery Holder Installed Coloured wires are the "instrument in" cable "Instrument In" connection to t...