boss RV-3 repair attempt

[choklitlove]

i found a RV-3 digital reverb/ delay pedal for $25.  it looked to be in great condition, but it doesn't work.  too good to be true...

anyway, here's what happens: when connected to wall wart or a battery or both, the light is always on even when "switched" via stomp.  although the light is on, there is no effect, but the "balance" knob affects the sound ever-so-slightly.  but no effect.  i thought this might be a switch problem, so i disconnected the two wires from the switch, and touched them together, but this made no difference.  i looked at the main board a little, but being that it's almost all smd and ic's, i hope that's not where the problem is.

GGG has a schematic, so it might help: http://www.generalguitargadgets.com/boss/BossRV-3Combined.gif

anyone have any ideas?  thanks!



oh yeah, aaron: i think a repair (of manufactured stomps) forum would be cool...

[nag hammadi]

i have one of those that is broken as well.  what SUCKS is that my bride saved up for a while and bought it for me out of the blue, brand new. 

it lasted a month.  that is pretty much what made me swear off mass produced pedals (and later on, amps) until today. 

i second the notion for the commercial pedal repair form.

[cd]

Looking at that schematic, the footswitch tells the computer (the M37470 chip) to do something, which it then passes on to the FET switching.   I would start by checking the voltage on the gate of the each FET - it should change when the switch is depressed.  Going by the schem, they should be alternating - one will be high while the other is low, etc.