Digitech - PDS 1002 Delay [schematic]

[CheapPedalCollector]

I just got a PDS-1002 in the box, this thread is wicked helpful, thank you all.

I have delay but it's very distorted, so I bet it's an opamp, the ne570 or busted fet. Maybe it's also 4007 since the hold doesn't work but could be the footswitch I guess. Will post results to help anyone else later.

[CheapPedalCollector]

Been ages since I worked on DOD/Digitech stuff in any capacity, I remember why I hate them now. Awful mechanical designs, the way they put the molex connectors is beyond stupid and it bends the input pot. Wasted 10 hours on it, can't find anything wrong. I suspect one of the FETS is bad but I don't have or can find any P100 or P200 ones. Just gonna sell it for parts.

[CheapPedalCollector]

Dug this thing out again as I didn't want to be defeated.

In my unit I was having the same issue with the mute circuit being always engaged. C35, C36 and C37 were all bad (between 2.7 and 3.3uf). Q8 was also bad. Replaced and the unit is working as it should again.

Including pic with their location on the circuit board.

Subs for PN100A and PN200A are 2N4124 and 2N4125 if needed.

[zwkelly]

I'd like to revisit this thread - it has been so useful.

Same story - PDS1002, won't do all the things, but kept it powered yesterday and now it works. I can use the first mode - 125ms - and all is good. However, I can't use 500ms or 2s. Any advice on getting all the modes to work? Everything else is there at this point.

I have two of these, which has been useful for comparison. One works just fine, and now I'd like to get this one back up to par.

Thanks,
Zach

[CheapPedalCollector]

The connectors get dirty too check those and make sure they also have enough tension. Clean the switch. If it's not that maybe you have some bad ram or the selector has issues. Those caps I highlighted have something to do with all the delay modes and the middle one is often inserted backwards on the board.