1979 Boss DS-1 stopped working - no sound at all

[pete_g]

Out of the blue it stopped working. No sound at all. Tried different power and battery, neither work. The momentary LED on this model doesn't come on at all either. Where is the best place to start? I've looked up different webpages on this question but haven't found an answer to lead me in the right direction. Could it be a diode issue? The foot switch seems to function momentarily - there's continuity. No caps resistors or diodes look burnt or blown.

[GGBB]

Is power getting to the pcb and components? Check the input jack to make sure ring is making contact and grounding the battery/power connection.

[pete_g]

Yes, power is getting to the pcb

[GGBB]

Follow the troubelshooting guidelines in the DEBUGGING sticky post in the main Building your own stompbox board - specifically, post voltages. Also look into using an audio probe.

Also - you should re-post in Building your own stompbox - far more people watch that board than this one.

[m_charles]

not really giving much info here to work with. first step would be to simply remove the pedal from the housing (or partially remove) and look for super obvious things. A wire that broke loose, a loose nut on a jack or pot, those kinds of things. Very often its as simple as that.
that said, the first thing that came to my mind was that you or someone else plugged in the wrong power supply and cooked it without realizing (total speculation on my part). This can result in a dead pedal that will still get power to the PCB when testing...

[pete_g]

I've built over 150 pedals so I understand the basics of looking at jacks, power wires etc. But the pedal has not moved or changed power supply. It just stopped working. There are so many wires coming off the board, tracing the circuit is different than building your own. If there's no obvious thing to look for then I'll just keep looking until I've worked it out. Thought there may have been similar issues someone may have had that could narrow it down.

[Phend]

My bet is the switch has gone bad, 2 many stomps

[ElectricDruid]

While I generally agree that "mechanical" is a far more likely failure than "electrical", if it's a 1979 pedal, I think probably all bets are off. It's not unlikely that *any* part might have died after 40+ years.

Definitely start with the easy and obvious stuff: broken wires, cracked joints, power, wrong-power-applied, bad pots, bad jacks, etc.

After that, pretty much the only option is to start at the beginning and work your way through. After 150 pedals you clearly know what you're doing debugging a pedal, so you know the drill. However, if you get stuck or short of ideas, I'm sure we can provide some!

Good luck!

[antonis]

Check all red circled points for +9V ..



P.S.
Not sure for R30 & R31 correct orientation but they should have +9V on one of their legs..

[Rob Strand]

I'm with antonis on this one.  Because of this,

The momentary LED on this model doesn't come on at all either.

Could also be the footswitch, which can be easily confirmed buy flicking a wire across switch contacts.

IIRC, there's quite a few variants of the PCB for the DS-1.  The 1979 model might not match antonis's pic 100% (which has flat ribbon cables.)

[pete_g]

Thanks for that info. I'll try it. I tried the foot switch and it works fine

[antonis]

IIRC, there's quite a few variants of the PCB for the DS-1.  The 1979 model might not match antonis's pic 100% (which has flat ribbon cables.)

Yeaaapp..

https://www.hobby-hour.com/electronics/s/sd1-super-overdrive.php

[ElectricDruid]

https://www.hobby-hour.com/electronics/s/sd1-super-overdrive.php

Ummm, remind you of anything?!?

[antonis]

https://www.hobby-hour.com/electronics/s/sd1-super-overdrive.php

Ummm, remind you of anything?!?

Could you plz helr me, my beloved boyo..??
(advanced age poor memory..)

[ElectricDruid]

https://www.hobby-hour.com/electronics/s/sd1-super-overdrive.php

Ummm, remind you of anything?!?

Could you plz helr me, my beloved boyo..??
(advanced age poor memory..)

I only meant that it looks a lot like a Tube Screamer to me. Not that I'm implying that Boss might have received "inspiration" from anywhere else, of course - heaven forbid!

For the record, the first TS-808 Tube Screamer came out in 1979, and the SD-1 Super Overdrive came out in 1981, so a couple of years later.

However, this Premier Guitar article suggests that Boss had a patent on asymmetric clipping with the earlier OD-1 (which we were talking about here) which is supposed to explain the use of symmetric clipping in the TS-808:

https://www.premierguitar.com/gear/tube-screamer-history

So did Boss get there first with the OD-1, and then Ibanez have all the success with the TS-808? Maybe. Either way, the SD-1 is a derivative of one or both of those pedals. The only question is "which?"!!

[Rob Strand]

SD-1 isn't the same as DS-1

[ElectricDruid]

SD-1 isn't the same as DS-1

No, sorry, I was going off on a side-track there.

Do carry on...

[pete_g]

Sorry to return to this, but I've checked the power rail and ground points, loose or broken wires, I be tried a few times, going over it, but can't work out why it doesn't turn on. I'll come back and see if there's any suggestions. I'm just not sure where I may be getting stuck. The switch is working. The + side rail has power, the jacks are connnected, (the LED should turn on anyway) so the issue is no power even to light the LED. I'll keep trying, but wires keep breaking off and I have re solder then after lifting the hood and checking both sides. I might have to in solder diodes, one by one, I think...

[Fancy Lime]

SD-1 isn't the same as DS-1

Names from an innocent time, when no one could imagine that one day "helpful" autocorrect and "smarter than though" search engines would make it so much harder to distinguish between DS-1 and SD-1 when searching information on the interwebs.

[Ripthorn]

If the LED isn't lighting up and you get no signal, my guess is the flip flop switching. Possibly a dead transistor or something similar. Try injecting signal into the beginning of the audio path and probe the output of the audio path, eliminating the bypass switching and see if you still have an issue. As I recall, the LED ground is all tied in to the bypass switching mechanism, so it fits.