Any ideas please?

Thanks Steven,great to hear it cán be fixed, let me know when that gray matter came up with the solution!

Bumping this thread. Got similar problem! Setting TP1 does not change the behavior of the depth knob. After measuring I got fed up, and I baldly replaced Q2, U4, U5, U6 and even U8. Shotgun approach.... But the issue remains the same! This circuit has got me baffled; not understanding why the intens...

Usually the red battery wire goes to one of the poles (I think its the middle one) of the 9 volt jack. The 9 volt jack is tip-positive, so the barrel is the ground, that connection seems to be missing. Then, you seem to be missing a connection from the 9 volt jack (the lug that connects to the tip) ...

Yes. 4069 was defective: Replaced and its sounding great again!

Excellent reply; thanks G! I've read up on the links carefully. I believe the circuit is this complicated due to the remote pedal function which allows to toggle between speed and effect on/off via an external footswitch. I measured a couple of voltages: 4013: 1: 12 (I-II/Vib LED on) // 0 (LED off) ...

Thanks for tracing the schematic Bernardduur, very helpful!! Got a defective unit on the bench: voltage regulator fried and leaking capacitors (10uF were all gone, rest looked OK, interesting detail.. bad batch?). After fixing these issues, the sound remains dry, and the switch for "Effect on/o...

Sourced quite a few locally which I bought all. I send you a PM...

Suspicion confirmed! I sourced a couple of vintage SAD512 chips and yes, the pedal works again as it should! The "Hong-Kong" SAD512d is definitely a bogus chip.

Are these Hong Kong SAD512D bogus? Or are there things in the circuit that could be the problem? Also replying to an older thread, but I'd just like to confirm kdude's story. I have the exact same problem; dead SAD512 and ordered a "hong-kong" one. Very faintly the BBD's output is audible...

Turn it back to stock until it works... Then mod it again, lol.

Sounds like you're right. These are the first to go. Also check the max660 as they tend to go afterwards, and replace the caps around the max887 as a precaution while you're at it!

Nice, good find. Well those SMD chips are pesky. If you don't have a hot air soldering station, you could try to use lots of solder and connect all 7 pins on one side, and heat it up. Same on the other side. Alternate between either side until the chip is so warm you it allows you to have both sides...

You sir, are a genius. It indeed did no longer short and that of course let to the C8 capacitor which was shorted out (somehow!). It worked back in the day... Ah well, all is good, totally rocked some Jimi tunes on the work bench. Learned I should always check the input capacitors as well now! THX! ...

Thanks for the messages! Continuity on TP4 is OK. Voltages rounded to first decimal without input-cable connected to guitar. With pots maxed out there is a huge feedback squeal as one might expect. IC1 TL2022 1: 4.5 2: 4.5 3: 2.9 4: 0.0 5: 3.1 6: 4.5 7: 4.5 8: 8.9 Q1 NTK275 8.9 8.8 8.5 Q2 NTK275 8.6...

Anyone a clue?

Help....! I am pulling my hair out over a Dunlop JH-2s Classic Fuzz. This unit has a very weak sound, can barely hear it if both the gain and volume are cranked to 100%. However, if I unplug the input, I can hear a horrible noise which responds well to the gain / volume, and I can definitely hear it...

You should probably have opened a new thread, but anyways, I'll try to help. Check the usual suspects. Get an audioprobe, listen where the signal comes in and where it goes away. Could be a hardware fault such as a faulty switch or jack plug. Measure with DMM if you get 9V or not. Just go over the b...

My trusted Boss DM-3 died on me. No more echo audible. I audioprobed the unit, but I cannot any affected (wet) signal appearing from the BBD stage. It has the MN3102 and MN3205. When I audioprobe the lugs, I cannot hear any ticking sound; it should, right? Did hear a squeal, on a lug, I guess that's...

I think I have one laying around somewhere. Still interesed?