ibanez super stl -weird problem

[randomair]

hello all. so i have one of these 80's ibanez super tube pedals, and there is something very odd going with it. first of all, it has bypass output but when switching the effect on, it has a very low intermittent farting output. hardly any signal is being passed. so i looked into it, checked values of caps, resisistors and transistors but everything seems to be reading fine, from what i could tell. so heres the weird part. i was applying pressure to different parts of the circuit board and noticed that if i placed my finger in the center of the circuit board, tada, the pedal worked and sounded really amazing. so my first thought was, well, theres a small crack in the board. i scraped back traces, re-soldered a number of connections and still, farting output and would only work is placed my finger across 4 certain resistors. basically if i short 4 particular resistors together the pedal works. maybe not that weird, but just really difficult to pin down. the resistors are r4,r5,r9,r11...there is a schematic i found below...if anyone has any ideas on where i can go with this, please shout me out, wanna get this pedal in the right, thanks.

[Mark Hammer]

Are any of the chips socketed perchance? I've had pedals in the past that had just the tiiiiiiiiiiiiiiiiiniest gap between IC pins and socket pins.

As well, it can happen sometimes that a component gets wiggled this way and that (e.g., vertically-mounted resistors) and the lead fractures. Of course, when you push on the back and the board buckles a wee bit, that may be enough to push the two fractured ends of the lead into contact with each other.

[randomair]

there are sockets...

funny you say this i just added sockets to the ics. i was going to switch the op amps out and try others because the pedal wasnt working at all (no output). i will check for cracks and see if i can track down this weird little circumstance. thanks for your reply.