ME-8 drive module problem

[fretzburner]

Hi,my me-8 drive module sound is very low.i could change it's parameters like tone,level,gain but i cant hear sound variation with gain parameter even from zero to 100.all the rest are ok regarding changing parameter values.the fx send dont have output too but if external drive selected the overall output will normalize but no effect heard from pedal connected to fx send/return.here is schematic of the gain section.
Any tips where to start?by the way what components IC6,IC7,and IC8 are?some kind of digital pot?

[fretzburner]

Anybody here can at least give me some ideas where is od in this circuit and where the distortion because i could here small volume out in od settings and not in distotion settings.And also the name or type of ic which look like two reversed triangles.
thanks

[teemuk]

The ICs are, like indictaed by the parts list of the service manual, TC4066BF quad bilateral switches.

The OD and the Distortion circuit are both right there in the posted schematic. Logic driving that nice collection of switches reconfigures that circuit to several different variations. The service manual doesn't go into greater details of explaining which of the switches are on or off in the different variations of OD/DIST. Experimenting and measuring should reveal it, though.

[fretzburner]

Yes those are switches and already did measure control voltages and these are the results.
Drive set to BD:IC6 pin13-0v,pin5-0v,pin6-0v,pin12-4.84v
                      IC7 pin13-4.84v,pin5-0v,pin6-0v,pin12-4.84v
                      IC8 all control pins 0v
then i  shorted the 3 in to out pairs which have 4.84v in the control and i get the output sound.i tried to change the drive modes and all have output now and the sound changed according to mode or drive type selected.My biggest problem now is the replacement TC4066BF not available here in the Philippines.I can't experiment by replacing those 3 quad switches.

[anchovie]

My biggest problem now is the replacement TC4066BF not available here in the Philippines.

Don't worry too much about the letters before and after the 4066 - the TC prefix is specific to Toshiba. CD4066, HCF4066, HEF4066, MC14066 and 74HC4066 would all work as long as the package type is the same.

[fretzburner]

Thanks anchovie for these valuable information but unluckily nobody carries SMD parts here.Have  to find somewhere else.

[fretzburner]

Sorry for bringing this up again.I already fixed this and what i have in mind now is maybe i could modify the drive section.As per schematic on first post the best thing to start is maybe the feedback diodes and diodes to ground.What's your opinions?