Friday, December 21, 2018

More Akai EWI3020m Pictures

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

Sunday, June 10, 2018

Sony PVM 1454QM Disassembly

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 obviously available back then...).

Sunday, January 7, 2018

Akai EWI 3020m Factory Reset | Glitchy Noise Fix

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


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 characters!).

But why are the preset sounds corrupted too? 

It turns out that tuning / calibration data is also stored in user-memory!
Dead EWI3020m "CMOS Battery"; soldered directly to the PCB!

Easy Fix

If you really don't want to try desoldering the battery and installing your own, then you don't have to! Just repeat these steps each time you power on the 3020m:
  1. Factory reset your 3020m
    1. Switch off the power
    2. Press and hold [UP] + [DOWN] + [WRITE]
    3. While still holding the buttons, switch the power on.
    4. The 3020m should boot, and the display should show "ALL DATA CLEAR"
  2. Auto-Tune your 3020m
    1. Wait about 20 seconds after switching the 3020m on
    2. Hit the [AUTO TUNE] button
  3. Enjoy ! :)
    1. If you're playing with an external wind controller over MIDI, remember to set the 3020m up to receive "breath data":
      1. Hit the [MIDI] button
      2. Hit the [VCF] / [2] button to enter the "breath" setting
      3. Press the [VALUE +] button once to set the value to "BREATH"

Permanent Fix

The best approach is to replace the internal battery with some replaceable 3.3v battery. I used a CR2032 coin cell and holder because they're easy to find and easy to replace.

Then, after replacing the battery, follow the steps above to reset your 3020m.

I plan to post a small guide on replacing the battery in the future! Until then, just make sure you get the polarity right! :)

Hope that helps, and all the best of luck!

Akai EWI3020m Disassembly & PCB Pictures

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 the I/O PCB