#1
I have a Boss DS-1 that has no power. I am decently familiar with circuits (new, but learning quickly). I will start with the current condition of the pedal.

Right now the pedal produces no sound on or off whatsoever and no LED. I haven't been able to locate a bad diode, resistor, capacitor, or anything.

Now, what happened. A couple years ago, I was playing it and it popped, when engaged it would make some real bad screeches and that was it. I tried to use the warranty but it was expired, so I opened it up with almost no knowledge, but quickly found that the D1 diode was in half, easy right? Well I went to radio shack and got what I thought was the right one and put it in, still didn't work. I gave up for a couple years.

I decided to try again on it. Got a 1N4005 Diode to replace the D1 again and realized I had previously used a 50v diode when it needed a 400v, I got a 600v 1N4005 and installed it. And now it won't turn on at all. I was assured online that the 1N4005 would work just fine in place of a 1N4004.

I went ahead and replaced the D6, D7, and D8 diodes to no avail.

What I'm trying to figure out is where to start now, it's clearly a power issue. I get nothing whether using the power supply or battery. I ordered a Monte Allums rectifier mod for it, hoping that one of the components in the kit will be the solution.


Short story: Replaced D1, D6, D7, and D8 diodes and no power or sound whatsoever.
#2
Just buy a new pedal. They are $50 brand new.
Last edited by bobathin at Oct 16, 2015,
#3
I know they're cheap, I am trying to understand the problem so I could save myself $50. I know it's not much but I like to fix what I can.
#4
Quote by Fireproof13
..... but quickly found that the D1 diode was in half, easy right? Well I went to radio shack and got what I thought was the right one and put it in, still didn't work. I gave up for a couple years.....

...I decided to try again on it. Got a 1N4005 Diode to replace the D1 again and realized I had previously used a 50v diode when it needed a 400v, I got a 600v 1N4005 and installed it. And now it won't turn on at all. I was assured online that the 1N4005 would work just fine in place of a 1N4004......

....I went ahead and replaced the D6, D7, and D8 diodes to no avail......
.


You're just random guessing. Replacing all the diodes and hoping for something to happen?

The D1 diode is the pedals reverse polarity protection diode. It was broken in half because it overheated and cracked in two. Why? Because the pedal was drawing LOTS of current that was passing through that diode at some point in its life. Most likely because the input power supply voltage into the pedal had been reversed at some point. IN400x series are rated for 1Amp only, after which they can go pop.

For D1 the pedal doesn't need a 400v, 600v or anything higher than the 50 volt diode. Why? Because the most the pedal should ever see in terms of volts is the 9 volt battery, or a 10 volt power supply. Even the 50v diode is overkill, but its the smallest volt rating you can get in the IN400x series.

So, I hope you put the new D1 diode in the exact same orientation as the original. The pedal itself will NEVER work if you put it in backwards and you risk blowing D1 again if you have. Diodes only work one way. That goes for ALL the diodes you swapped.

After this, use a 9v battery to test it (important). If you have a power supply check it is the correct voltage AND polarity for the pedal before trying it again.
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Last edited by Phoenix V at Oct 17, 2015,
#5
Yeah I know the correct orientation of the diodes. I now did the Monte Allums Rectifier mod and I get power now, but just a hum when it turns on. So one step closer I guess.
#6
After ensuring that no diodes or electrolytic capacitors are installed backwards or damaged, if you have a multimeter to measure the voltages look up the pin assignments for any active parts (I do not have the schematic, but I assume it has at least some chips and not just discrete transistors) and ensure that they are getting their correct voltages on their power pins. Most devices experience problems or failures in their power circuitry or power supplies and that is the first place to look.

Besides solder joints breaking it is less likely that the signal path has experienced a failure. If it has, use of an oscilloscope to trace the signal from input to output is a great asset if you have one.

Just my $0.02 worth from my *extensive* experience debugging electronic circuitry.
#7
I did figure this out, it was the op amp. I replaced it with the double op amp adapter from Monte Allums and it fixed the problem right up. The pedal sounds great now!