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What might be wrong with this old piano?

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fredand44

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Hello Guys,
I got two kids, son and daughter, both are a bit interested of playing piano.

A couple of years ago my brother in law gave us an old retro piano. That piano works fine and my son loves it. It uses a 12v adapter.

index.jpg

A months ago I found a similar piano in my mothers basement. Perfect I thought now my daughter could play as well. But this one did not got a adapter. But if I see correct it uses a 9v so to day I bought one: https://m.clasohlson.com/se/Nätadapter-9-V-1-A/Pr512786000

9599636340766.jpg

But the piano for my daughter do not start with it.

index2.jpg

I tried it out with the piano for my son and even though it says it needs 12v it works fine, so the adapter seems to be ok.

What do you think guys, how would you error search the piano? It is in such good condition do it feels wrong to not give it a shot.
Best regards
Fredrik
 

I wouldn't go any further before getting a compatible adapter. You could spend days solving a problem that is nothing more than lack of power. I would think the 1A rating is probably too small for an instrument like that too, with two amplifiers inside it I would think at least 2A would be needed.

Brian.
 

The DC polarity may be reversed in the case of the non-working unit. Look closely at the jack on each piano. Often there is a diagram telling what polarity the unit needs. Do you see 'center positive' or 'center negative'? If they are different then that explains why one piano works from the adapters.

A voltmeter confirms polarity.

Can you run the unit on batteries?

Examine the adapters in case you find an option to change the DC polarity. This might be a switch, or a reversible connector. If not then you can clip the wires (unplug and discharge the power first!), cut away insulation, then reverse the wires as you reconnect them. Apply tape or heat-shrink tubing to prevent short circuit.
 
Do both "pianos" have the same polarity for the power connector?
How old are your kids?
Both instruments are toys, and can not be used for serious piano learning.
If any of the kids is interested enough to begin with piano lessons, you need a better instrument.
When that day comes, discuss it with the piano teacher.
A usable digital piano with weighted keys starts at about $300
 

So the newly found piano does not run with batteries? If yes (there is a battery compartment and you put on fresh batteries), then the piano is probably working fine. If no, you need to dig deeper.

Did you try the 12V adapter with the 9V piano? Also note whether any lights come on when you plug in the adapter?

When you plug in the 9V adapter and connect to the machine, does the adapter gets warm to touch?

As you have found out, the adapter is fine but the machine may have some issues.
 

Hello Guys!
Thanks for all interesting replies.
Unfortenately I am gone from home/the pianos for a couple of days. But when I get back I will try the newly found Casio piano with batteries asap, good idea!

I took a couple of more photos of the two pianos. I am not sure they will tell us anything of polarity. Below is a photo of the Yamaha piano interface.

1.jpg

...and some info

2.jpg

Below is a photo of some info on the backside of the Casio piano.

3.jpg

Yes I tried the Casio piano with booth adapters but no sign of any "life", no lamps blinks.
Btw my kids, son 9 years, daughter 6 years.
Best regards

- - - Updated - - -

... Sorry missed to say that I did not notice if the adapter get warm. I guess that would be an indication that the polarity might be wrong if the machine does not start? When I get back I will investigate it.
 

The recommended ad-5 is center pin negative from a web search. Your Yamaha adaptor is center positive if I'm looking at photos correctly.
 

First of all..
Do not plug either AC adaptor into the Casio again!

There aren't old batteries in that Casio are there? If so they might have leaked which might have damaged the unit.

The Yamaha has a center positive polarity plug (though the symbol is half covered since you didn't remove the adaptor). You need to either look at the Casio plug or post a picture of the plug (without the adaptor cord plugged in)

With the poor angle of lighting it's hard to be sure if the Casio requires 5W or 3W regardless the 9V with either wattage means the 1A wall wart should be enough for the Casio. Given the unit uses 6 alkaline batteries (in series) for 9V the unit probably doesn't require as much current as the wall wart can supply.

Looks like a negative center plug see the amazon listing for a replacement AD-5 https://www.amazon.com/Casio-Keyboard-Power-Cord-Adapter/dp/B01N7FCC3P

Applying reverse DC plugs could potentially damage a device. You should always check the polarity BEFORE plugging in some random wall wart adaptor.
 

I was unable to determine polarity of adaptor you bought. Since it powered the Yamaha I have to assume it is center positive also. It looks like your Yamaha specifies a voltage range (9-?vdc). Can't make it out from photos since cord is in.
 

I was unable to determine polarity of adaptor you bought. Since it powered the Yamaha I have to assume it is center positive also. It looks like your Yamaha specifies a voltage range (9-?vdc). Can't make it out from photos since cord is in.

The second picture of the label on the back shows it requires 9VDC power.
 
Hello,
Thanks for that info! I bet that is the reason. As someone mentioned above, isn't it possible to cut the cable, switch the wires to change the polarity?
Best regards
Fredrik

- - - Updated - - -

Hello,
No there was no old batteries in the battery compartment. The piano is almost in mint condition.
Yes I am sorry for the poor photos especially of the interface of the Yamaha. I took them quick before I had to go.
In the photo of the info of the Casio:
https://www.edaboard.com/attachment.php?attachmentid=154648&d=1564415151
... I think I can ser 6.0 w but I am not sure.

I will see if I did take one of the casio, back in a minute.

- - - Updated - - -

Hello again,
The interface of the Casio looks like this:

casio.jpg

(I was warned by the moderator to use links to different servers, so sorry for that. Is there a way to attach images?)
Best regards
Fredrik
 
Last edited by a moderator:

Hello guys,
I took an other glance at the spec of:
https://m.clasohlson.com/se/Nät...-A/Pr512786000
It says (in swedish) it does not hot any center pin. Perhaps then I could not just cut the cable and switch the wires to change the polarity?
Best regards and again thanks for all replies.
 

The new picture shows a - polarity for the center and + on the outside of the plug.

You can swap the wires, but if you do scratch out the polarity info on the wall wart and mark it somehow with the modified polarity, otherwise someone might use it on the Yamaha or another device with the opposite polarity. Considering they are for your young kids, that is more likely to happen than not.

You might consider using colour coded tape for each keyboard/wall_wart pair. e.g. blue on one set red on the other. Then they will be less likely to swap the two wall warts.
 

Hello guys!
Thanks for all help, I learned alot!
I found an old universal adjustable adapter in a box when I was looking for a hdmi cable.
It turned out that it was of right kind.
I also managed to return the first adapter to the store.
Best regards and again thanks for all help!
 

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