# Yamaha W5 keybed

**URL:** <https://forums.syntaur.com/t/yamaha-w5-keybed/6483>\
**Category:** Synth Repair\
**Created:** [December 4, 2023, 6:51am UTC](https://forums.syntaur.com/t/yamaha-w5-keybed/6483 "2023-12-04T06:51:07Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![Keyboardist](https://forums.syntaur.com/letter_avatar_proxy/v4/letter/k/d6d6ee/32.png) [@Keyboardist](https://forums.syntaur.com/u/Keyboardist)\
**Post date:** [December 4, 2023, 6:51am UTC](https://forums.syntaur.com/t/yamaha-w5-keybed/6483/1 "2023-12-04T06:51:07Z")

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I have a Yamaha w7 with a weird issue. Only the top two or perhaps 3 keybed octaves are working. I’ve rest all connectors. Any ideas ?

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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:** [December 9, 2023, 7:19pm UTC](https://forums.syntaur.com/t/yamaha-w5-keybed/6483/2 "2023-12-09T19:19:27Z")

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Sounds like a loose cable either from the cable that joins the 2 sections of switch boards or runs to the main board

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**Author:** ![Keyboardist](https://forums.syntaur.com/letter_avatar_proxy/v4/letter/k/d6d6ee/32.png) [@Keyboardist](https://forums.syntaur.com/u/Keyboardist)\
**Post date:** [December 9, 2023, 7:39pm UTC](https://forums.syntaur.com/t/yamaha-w5-keybed/6483/3 "2023-12-09T19:39:21Z")

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Unfortunately it’s not a loose cable. Everything is seated properly. Checked the cable continuity, key-bed diodes and connectors, re soldered the connectors.

I noticed when everything is connected and i play the lower octaves, it activated some buttons functions. Thought there might be a short circuit somewhere.

Issue still persists.

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<div class="post-metadata">

**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:** [December 10, 2023, 4:23am UTC](https://forums.syntaur.com/t/yamaha-w5-keybed/6483/4 "2023-12-10T04:23:54Z")

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In this case it sounds like a main board ptoblrm. Of couse this is NLA. I could email you the SM if you nned it

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<div class="post-metadata">

**Author:** ![Keyboardist](https://forums.syntaur.com/letter_avatar_proxy/v4/letter/k/d6d6ee/32.png) [@Keyboardist](https://forums.syntaur.com/u/Keyboardist)\
**Post date:** [December 14, 2023, 7:19am UTC](https://forums.syntaur.com/t/yamaha-w5-keybed/6483/5 "2023-12-14T07:19:56Z")

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Thank you. I’ll give it a try or two, if not the it will end up for parts. I have a suspicions it is a short somewhere on the scanning circuity because when i disconnect the keybed, the buttons work perfectly and when i connect it back, they behave oddly

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<div class="post-metadata">

**Author:** ![Keyboardist](https://forums.syntaur.com/letter_avatar_proxy/v4/letter/k/d6d6ee/32.png) [@Keyboardist](https://forums.syntaur.com/u/Keyboardist)\
**Post date:** [December 26, 2023, 6:19am UTC](https://forums.syntaur.com/t/yamaha-w5-keybed/6483/6 "2023-12-26T06:19:14Z")

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Found the cause, badly leaking 220uf 16v caps. They l’ve damaged the board.

So i replaced some and it started working. Then whn continues with the rest, now the system doesn’t noot successfully every time. I checked all the work i’ve done and also surround traces nd components. Found nothing. All voltages are good and no ripples.

Any Ideas on how to approach this methodically , like looking for certain signals ??  
Thanks