Maxon 808 Repair issues

[Murphy1505]

Hey everyone,

brand new to the forum and to pedal building and repair in general, recently picked up a Maxon 808 on the cheap because the guy had messed up the power supply and fried D5,  that was easy to fix and it now powers up

my issue is that when I plug the pedal in and the switch is off I get signal through to the amp (AC15) but when I engage the pedal I get nothing

apologies if this has been asked and answered but I did some looking and couldn't find my answer

nothing appears to be blown or broken and ive attached a picture

any help would be appreciated


VOX AC15
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PHase 90
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Eventide H9 MAX

[PRR]

Welcome.

https://www.diystompboxes.com/smfforum/index.php?topic=29816.0

[antonis]

Hi & Welcome..

Can't see any D5 either on your PCB or any schematic available..



When footswitch is ON does indicator LED lights..??
If yes, measure for +9V on both ICs pin 8..
If it's OK, measure for +4.5V at both ICs pin 3..
If the above are OK, come back and report it..
(we will definately tell you to replace op-amps but wait till we'll indeed tell you that..)

[willienillie]

Can't see any D5 either on your PCB or any schematic available..

Right next to the power jack.

Just labeled 1N4001 on the schematic you posted*.

*Edit:  Weird that schematic has opamp in/out buffers.

[antonis]

Ahaaa..!!

It counts LED also for a total of 5 diodes..