Need help to diagnose a sick Yamaha AG Stomp

[MyloGuitars]

I am helping a friend find new homes for some acoustic guitar gear, including a Yamaha AG Stomp, which I can't get to work.

The unit powers on and I can navigate among the user and preset patches, but I cannot get a signal through the unit to an amp. I triple-checked the cables (mono TS instrument cables) and the connections (Input: Mono and Output: L/Mono) and tried several different preset patches, as well as Manual mode.

I get an ominous rhythmic pulsing sound that varies in loudness with the Volume knob but is fairly low level. No signs of any guitar signal from several different guitars and a mandolin - all which produce a normal signal when plugged directly into the amp.

I also performed a factory reset, with no discernible change.

Any suggestions how to further diagnose? Is it dead?

[shufflebeat]

First thoughts are a power supply problem which might be an internal component misbehaving. Are you 100% using the right DC supply? If so a trip to the menders might be worthwhile, it's a great box.

[MyloGuitars]

You nailed it, @shufflebeat - there were 2 power adapters in the bag with the pedal and I grabbed the wrong one. Works like a charm with the correct power!!

[shufflebeat]

Excellent.

The AG is definitely worth getting to know. Really musical compressor if used sparingly, lovely chorus and the best notch filter system I've ever used.

Best of all, the mic modelling and the ability to save different presets for different instruments.

Check out what the shift button does for the EQ section.

One more point - there are 2 outputs (L/R) both are balanced on TRS sockets so no need for a DI box, just TRS/XLR adaptors or leads and straight into a mixer.

[shufflebeat]

Just nipping back to this thread from the future to point out that the "DC supply" I refer to in an earlier post should actually be AC (12vAC). This came back to my attention recently so I thought I'd correct the info just in case someone does a search.

[MarkF_48]

A bunch of years ago I bought a Brother label maker off Amazon to label 3-ring binders, electrical switches, and other things. When I tried to figure out what wall wart adapter went with a a piece gear that was in a box with about 10 others one day, I set about labeling all the adapters with the name of what they went with.

I have a DG-Stomp I got years ago and it has about the best variety of patches compared to a couple other multi-fx boxes I've got. I did have to change the memory coin battery once when patches weren't loading correctly. I don't think the AG-Stomp uses a battery for memory retention.

[grandstick]

I found a “broken” DG-Stomp for sale on Craigslist several years ago. After a few minutes research, I determined that it was the same issue - I dug out a 12 volt AC power supply from my seemingly endless bag of them and it worked just fine. The only thing I needed to do was replace the internal backup battery.