New to MSX world (Casio MX-15) | MSX Resource Center (Page 4/4)

By Jipe

Paragon (1551)

22-05-2009, 17:53

are you sure the power supply is for the MX-15

if the MX-15 is making with 74HCxx or 74HCTxx chip the power is done

but if exist one or more 74LSxx chip the mini of power is 4,75v

By Desperado

Rookie (22)

22-05-2009, 18:07

The transformer has the Casio logo on it, but it looks like it had been fixed a number of times. Have to recheck once I'm back home.

By Jipe

Paragon (1551)

22-05-2009, 18:13

considering the ferrite coil it is possible the power is "decoupage" model and increases the power voltage
at this time that would like to say which does not function any more

By dhau

Paragon (1570)

22-05-2009, 18:59

My quick test for MSX is to power it from PC AT power supply (+5V and GND is enough for test, no need for +/-12V). I just solder a molex connector for VCC and GND points somewhere on PCB (after all the native power supply cirquit). Usually stuff works fine, and I just have to find a defective power regulator, dry capacitor or dead transformer.

By Desperado

Rookie (22)

23-05-2009, 14:55

I attached a 5V universal plug to it. The result is still the same: The screen flashes for a second, no beep whatsoever. I can now measure 5V on all of the ICs.