# Ensoniq SQ1 - No sound but loud hum

**URL:** <https://forums.syntaur.com/t/ensoniq-sq1-no-sound-but-loud-hum/7870>\
**Category:** Synth Repair\
**Created:** [September 11, 2024, 8:18pm UTC](https://forums.syntaur.com/t/ensoniq-sq1-no-sound-but-loud-hum/7870 "2024-09-11T20:18:02Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Fishsqueezer1](https://forums.syntaur.com/letter_avatar_proxy/v4/letter/f/cab0a1/32.png) [@Fishsqueezer1](https://forums.syntaur.com/u/Fishsqueezer1)\
**Post date:** [September 11, 2024, 8:18pm UTC](https://forums.syntaur.com/t/ensoniq-sq1-no-sound-but-loud-hum/7870/1 "2024-09-11T20:18:02Z")

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I just picked up an Ensoniq SQ1 for cheap - took a chance. Got home, turned it on, there is only a loud hum. No sounds at all using either L or R output. No sound from headphone jack. Any advice on first things to check? Thanks!

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**Author:** ![PCM-tech](https://forums.syntaur.com/letter_avatar_proxy/v4/letter/p/8491ac/32.png) [@PCM-tech](https://forums.syntaur.com/u/PCM-tech)\
**Post date:** [September 12, 2024, 9:14pm UTC](https://forums.syntaur.com/t/ensoniq-sq1-no-sound-but-loud-hum/7870/2 "2024-09-12T21:14:23Z")

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SOL…bad decision. no new parts available. (main or p/s)

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**Author:** ![rludlamjr](https://forums.syntaur.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@rludlamjr](https://forums.syntaur.com/u/rludlamjr)\
**Post date:** [June 27, 2025, 5:53pm UTC](https://forums.syntaur.com/t/ensoniq-sq1-no-sound-but-loud-hum/7870/3 "2025-06-27T17:53:24Z")

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I’ve spent a ton of time working on an Esq-1, so not the same but I would recommend a few starter things:

1. Check all of the voltages coming off the power supply against the service manual to make sure they’re correct… if you have a short or some of those voltages aren’t right then you may have a burnt voltage regulator or a cap problem, etc.
2. Biggest simple issue I’ve found with my Esq-1 is it’s extremely sensitive to how well the keyboard is plugged in. I know that sounds dumb but it’s true. Not sure the sq is the same but in the Esq there’s a big ribbon cable that connects the keyboard to the main board. If it’s even a little loose my kb won’t work at all. Carefully unplug it and make sure it’s seated well on both ends.
3. On the Esq-1 I’ve had to do a soft reset several times as it stops working randomly. Check to see if there’s a similar procedure on the sq1