Deinyon's Blog Place

Just popped the lid on my EWI3020m again as part of a tidy-up and took some pictures. Enjoy! EWI3020m without its lid EWI3020m without its lid

Just popped the cover off my Sony PVM 1454QM RGB video monitor. Have had it for a few years, and it's always worked perfectly well - just took it apart for a second time to check more carefully for any obviously bulgy caps. It seems that these monitors (or at least their picture tubes) were manufactured in Ichinomiya in Aichi Prefecture, Japan . Apparently mine was manufactured in 1996. Mine had a few defects when I got it (missing Sony logo, kind of grubby, dumb calibration settings, base has been hacked apart for some reason - perhaps to fit into some rack mount?), but was overall a pretty good deal at $50, free delivery! Back of the Power Supply PCB The Picture Tube in the Sony PVM 1454QM Flyback Transformer in the PVM 1454QM Deflection Yoke in the PVM 1454QM Anode Cap So all in all, it's a little dusty - but I really love the no-expense-spared modular design! Not entirely sure what's the deal with the paper phenolic board though (FR4 was o...

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...