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By 5_speed_shifter
I have a cheap-o chinese MP3 trigger setup for a couple of years now as an alarm clock and works flawless.

I bought a sparkfun MP3 trigger and I cannot get any audio out of it.

1 - using 5V DC power. Supply is capable up to 1 amp. I soldered to the 3.3-12V pins under the DC jack.
2- the board powers up. I get a solid red LED.
3 - upon powerup, I get 3 flashes from the GREEN LED indicating that the micro card is loaded with a file OK.
4- I loaded the test file from your troubleshooting web page. It only has the 1 test file on it and I can play that file OK on my PC.
5 - The firmware test is OK. With no file it flashes the sequence that it should.
6- I used the default setting of active speaker. I ran the L,R, and gnd (tip, ring, sleeve) to a small 20W amp connected to a speaker. This amp works OK with my phone. No sound from the trigger.
7- when I play the MP3 via the rocker switch, the LED turns green and there is no audio. It will stay green.
8- I changed the solder bridges to "headphone" and I can hear "hiss " in the headphones from the op amp. Still no audio. These are earbuds that test out ok with my phone. (TRS 3.5mm) Again, green LED stays on, no audio.

Any ideas? I exchanged this unit for a previous one that had the same problem. the plastic bag it arrived in is stamped batch # 114817

please advise. I am out of ideas on what is wrong, or what I can try next. The card works OK in the other MP3 trigger I have.

thank you
User avatar
By robertsonics
If the LED turns green, then the MP3 Trigger is playing a file. I suspect something is wrong in your audio output circuit. Have you tried plugging headphones into the audio output jack?