What's an adapter?

@Raymund: does it do this when plugged into other wall outlets? Or other buildings?

@Jason: At least in Canada, we often called PSUs a "power adapter" or just an "adapter" for short. More pleasant than wall-wart 🙂

Yes also in other buildings and other wall outlets this problem occurs.

If you're using the original adapter and it's doing this, then either the adapter is damaged or the MODX. It really looks like you have to take it to a service centre for repairs.

The only stopgap measure I could suggest is trying another Yamaha PA150 power adapter to see if it's the power adapter that's causing problems.

The smart and responsible thing to do is to have this looked at by an authorized service center. Issues with power should always be taken seriously, they are an indication of something simple or serious — Could be just how the adapter fits into the receptacle (wall or power strip), or it could indicate a more serious cause. The thing is to know for sure. In all likelihood you’re still under warranty... so it’s smart from the point of view to have it looked at if it persists, or at least report it... it’s the responsible thing because if there is an issue, say with the power adapter, the larger community will want to know and have the issue officially addressed.

Maybe it’s nothing at all serious, but follow up on this by at least calling your Yamaha representative. The only way “known issues” get to be known, is if those using it report it.

Thanks in advance.

I brought it to the service center, investigating now......

BTW: thanks for clarifying. I use all kinds of adapters. Power adapters, various audio cable adapters (XLR to 1/4" TRS or 3.5mm stereo to dual 1/4" TS or ...), video "adapters" (USB to HDMI), sometimes external MIDI gear employs special cable adapters, etc. Your additional detail helps clear up the ambiguity of what kind of adapter was referenced.

Glad you're getting your MODX looked at.

MODX fixed now, I got a the digital main board replaced.

Weird problem!

I have a MODX8 that started behaving the exact same way last night. I actually have two PA150 power adapters. Keyboard is behaving exactly the same way with both adapters. I also tried different wall plugs in different houses (it started doing this while I was at band practice). I bought the keyboard used from Guitar Center as an online purchase. I just contacted them and, not surprisingly, they informed me that it is not covered by any warranty under them. Today is Sunday, so I have to wait until tomorrow to contact Yamaha to see if it is covered by any manufacturer warranty. I'm pretty sure it is only a 1-year warranty, which probably means that has expired... My fingers are crossed very tightly, but I have a feeling this is a lesson in why you want to buy new. 🙁

The Yamaha warranty is for the original purchaser of the instrument, only. So you will not be covered by the factory warranty.

Guitar Center, afaik, offers their own extended (store) warranty which covers things for an extended time. I’m sure they offer it on used gear (usually a good idea). Apparently, you did not purchase that warranty when you purchased used gear. LINK — GC Pro Coverage see the Terms & Conditions… I know they must have offered this to you if purchased in store and it definitely is there when you checkout your cart if purchasing online.

You should definitely reach out to the store — explain your situation. Get their recommendation.

A unit that is powering off immediately is not getting correct voltage under the current conditions.
A unit that is powering down after a specific amount of time is following the Auto Power Off protocol.
A unit that does not power up at all, or only powers on partially, could be a serious problem (as outlined in the above posts)

Power supplies should be disconnected from the wall when not in use for an extended time, and should never just be just left plugged into the wall with nothing connected… or used on products not rated for their Amperage and Voltage (this can burn them out very rapidly). Hopefully neither of your PA150 adapters were used to power something they were not rated for… which, literally, can burn them out.

It does not necessarily mean that there is an issue with your MODX, (it is supposed to protect itself — and if it is powering off immediately, it is). The issue could still be with the Power Adapters… if the instrument flips off immediately, it is protecting itself.
If it does not power on at all or only partially… that could be more serious — the way to know for sure, is an authorized service center.

Having two adapters could just mean (as unlikely as it may sound) they are both no good or were both abused by the original owner. Unplug completely for a while and then try again.

Definitely call the GC Store.
Definitely call Yamaha Customer Support.
Describe exactly your symptoms.
Let us know.

I called both Yamaha Customer Support and Guitar center and both of them stated the obvious: factory warranty didn't transfer and I didn't buy any extended warranty through Guitar Center, so I was SOL. I brought it to an authorized dealer who originally could not reproduce the symptoms. Then, after powering off and on again for the ~30th, it did act up. He opened up the keyboard and found a piece of foam had dislodged and caused a short on one of the circuit boards. Once they secured that, they backed up the system, updated the firmware, restored it, and that was it. I'm crossing my fingers this is the only issue I have with it. I really love the keyboard.

Thanks for reporting the resolution detail.