# Yamaha CP4 E5 key full volume?

**URL:** <https://forums.syntaur.com/t/yamaha-cp4-e5-key-full-volume/9491>\
**Category:** Synth Repair\
**Tags:** yamaha, broken-key\
**Created:** [June 29, 2026, 12:50pm UTC](https://forums.syntaur.com/t/yamaha-cp4-e5-key-full-volume/9491 "2026-06-29T12:50:06Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Tycer](https://forums.syntaur.com/letter_avatar_proxy/v4/letter/t/d6d6ee/32.png) [@Tycer](https://forums.syntaur.com/u/Tycer)\
**Post date:** [June 29, 2026, 12:50pm UTC](https://forums.syntaur.com/t/yamaha-cp4-e5-key-full-volume/9491/1 "2026-06-29T12:50:07Z")

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Hi,

I am looking to purchase a CP4 from a local church. The E5 key intermittently plays full volume.

I would like to know if this is reparable.

I would also like to know what maintenance I should perform.

Thanks,

Tycer

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<div class="post-metadata">

**Author:** ![sargfowler](https://forums.syntaur.com/user_avatar/forums.syntaur.com/sargfowler/32/2120_2.png) [@sargfowler](https://forums.syntaur.com/u/sargfowler)\
**Post date:** [June 30, 2026, 7:00am UTC](https://forums.syntaur.com/t/yamaha-cp4-e5-key-full-volume/9491/2 "2026-06-30T07:00:22Z")

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Hopefully it will just need a clean on the keyboard contacts. It’s a common issue.

I haven’t checked the schematic, but most keyboards have two contacts to measure how firmly you hit the key. One of the contacts may be dirty and you get random volume from it.

Clean with IPA and a cotton bud.