Mojo Vibe

[lowell]

Working on broken Mojo Vibe. The wrong power supply was plugged into this pedal and now it does not work. I believe there are some protection diodes in there and they are 1N5817 schottky diodes. These diodes are rated at forward voltage drop of .45-.75 depending on current. Could I replace these w/ a 1N400x type? I'm thinking this will work but what might the 1N400x type not do that the 1N5817 would do better?

[lowell]

anyone have a schem for this pedal? There is signal but no effect.

[lowell]

If no schem... anyone able to explain how the voltage converter op-amp works? (MAX1044 ). Or if these pin voltages seem good or bad?

All are DC volts:

1 9.56
2 7.29
3 0
4 .28
5 9.56
6 6.8-7.26
7 7.2
8 .28

[cjlectronics]

I fixed one a while back. The problem was the MAX1044 was not driving the lamp. The Max1044 is configured as a voltage doubler, so the lamp voltage should be 15v or higher. I never could find a schematic.

The 1N5817 schottky diodes turn on faster than the 1N400X series. I believe the purpose for using these is two fold. One, to protect against a reverse polarity power voltage and two, to suppress transient voltage spikes. They kill two birds with one stone where the 1N400X just protect against a reverse power source.

CJL

[lowell]

thanks for you help!

[blubp]

Moo Vibe

I seem to have the same problem with my Mojo Vibe. It seems to work fine most of the time, but sometimes gives off a squeaking noise ( varies with effect rate ). High rates also causes the lamp to get "stuck" at full effect, resulting in no modulation. Iīve found various models of the max1044 - do you know the exact part number of the component used?

I bought the Mojo second hand - I love it, but because I donīt live in the US, it would probably be cumbersome and expensive to send the effect back for repair.

Thanks!

[cjlectronics]

MAX1044CPA, the 8 pin DIP I think. Its been a while??

CJ

[blubp]

Thanks! That saved my day

[blubp]

Max1044cpa

Just wanted you to know that i ordered a replacement for the MAX1044CPA, fitted it, and sure enough - it took care of the problem. Mine was only partially broken - it would't drive the lamp at high rates.