The first thing that comes to mind is, whether there is any air movement over the piano, especially from the outside where the temperature changes will affect the tuning. As soon as you have any temperature change, or if there is sunlight on the strings, everything goes off and you'll chase your tail trying to tune it. When I tune, the windows and doors must be closed, no fans, heaters, etc. No A/C blowing. I had a tuning where the room was cold from using the A/C. I spent 2 hours, and gave up and left. I came back later when the room was at room temperature, and it tuned up just fine.
I don't discount some other problem such as glue failure, delaminated bridges, cracked plate, etc., but temperature changes are first on my list.
Good luck.
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Paul McCloud, RPT
Accutone Piano Service
www.AccutonePianoService.compavadasa@gmail.com------------------------------
Original Message:
Sent: 02-20-2026 03:09
From: Keith Akins
Subject: 1980s Yamaha U3 tuning instability
Received a call for help from a non-PTG individual who has done some tuning and tunes their own piano. This U3 is their own piano not one of their customer's.
The problem is that particularly in the top section starting above the tenor they experience tuning instability such that while they are tuning as they check lower notes, many of those notes have deviated from being in tune.
Tuning pins are adequately tight; Bearing points have been lubed. Piano nominally at pitch. Positive general integrity of soundboard and bridges. Piano not being moved.
Since this occurs during the tuning process, seasonal humidity fluctuations are irrelevant.
What I'm wondering is if there is anyone who has experienced/observed a similar situation and if so if you determined a cause.
Also I'm wondering about the actual design structure of the piano. Almost all vertical pianos do not have a plate flange for the pinblock. Is that the case here? Any other design/construction details that could be of interest?
I want to be as equipped as possible prior to my visit to that piano, so all comments welcome.
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Keith Akins RPT
Menominee MI
(715) 775-0022
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