neilemborgo

i had the same issue, no output on DSP bypass. low volumes bleed on drive effects. good output on true bypass, no sound when effect is on. ended up replacing the U11 IC in the board. its a 2374A PWM DC/DC Converter. it fixed it for me.

i had the same issue, no output on DSP bypass. low volumes bleed on drive effects. good output on true bypass, no sound when effect is on. ended up replacing the U11 IC in the board. its a 2374A PWM DC/DC Converter. it fixed it for me.

i had the same issue, no output on DSP bypass. low volumes bleed on drive effects. good output on true bypass, no sound when effect is on. ended up replacing the U11 IC in the board. its a 2374A PWM DC/DC Converter. it fixed it for me.

Hello guys! I’m looking for help diagnosing my Line 6 M5 that currently has no DSP audio output. Current symptoms: * Pedal powers on normally * LCD/display works * Presets change normally * True bypass works perfectly * DSP bypass has NO output * Most effects have no sound at all * Some distortion/OD/filter effects produce very weak low-volume output * Delay/reverb/modulation effects are completely silent Additional important detail: Originally, the pedal would randomly RESET/reboot whenever changing presets. After opening the backplate and pressing/reseating some ribbon cables/connectors, the reset issue disappeared completely. So now: * preset changing is stable * but DSP audio is still basically dead Things I already tried: * different known-good 9V center-negative adapters * Zoom G3Xn adapter * factory reset * cleaned ribbon cable contacts/connectors with isopropyl alcohol * reseated internal ribbon cables multiple times * tested left mono input/output only What still works: * true bypass path * pedal boots normally * UI/display/controls all work What does NOT work: * DSP processed signal path Questions for experienced M5 repairers: 1. Are there known common failure points on the M5 that match these symptoms? 2. Which voltage rails should I check first? 3. Any known bad capacitors or regulators on the M5? 4. Has anyone seen “true bypass works but DSP path silent” before? 5. Could a ribbon/header issue still cause this even after reseating? 6. Is there a service manual or board schematic available anywhere? Any advice would really help be fore I start deeper component-level troubleshooting. Thanks!