Casio-ctk731| ac-input not working

Joined
Jul 6, 2024
Messages
2
Reaction score
0
Location
Belgium
Dear people of the internet

I've owned this casio keyboard for a while now and it used to be from my father. The pin that is found on the jack in the back of the keyboard was broken off and got stuck in the adapter ac plug. I was hesitant to repair the ac jack but after a few years of paying and playing on batteries i decided to order the same connector and a new adapter to try and fix my keyboard.

After soldering the new one in place and plugging in the adapter which has a specification of 12V, 1.5A and 18W of course it didn't turn on. (It's not because of sloppy soldering) I checked with a multimeter after plugging the adapter in and there seems to be 12V over the ac jack. There also seems to be 12V over the transformer. The diodes give a reading of 0.4V. I have limited electronics knowledge so i won't get any further than this. It's also not because the entire board is fried because the keyboard still works perfectly fine on batteries.

Is there anyone that could help with this problem or any solutions? I'd be happy for a solution that uses the dc connection from the batteries.

I'll leave the schematic for the keyboard below:


And my email if you want to contact me personally:

(e-mail address removed)
 
Joined
Apr 4, 2012
Messages
1,585
Reaction score
746
Its a nearly 30 yo keyboard valued today at a $200 replacement cost. Might be better off looking for another one and using the current one for parts replacement.
 
Joined
Jul 6, 2024
Messages
2
Reaction score
0
Location
Belgium
Its a nearly 30 yo keyboard valued today at a $200 replacement cost. Might be better off looking for another one and using the current one for parts replacement.
Thanks for the interesting reply i'll definitely keep this as a last resort. But i really want to try and fix it no matter what. As long as it works and i can't fix it i guess i'll just keep playing on batteries. Thanks for the reply!
 
Joined
Sep 19, 2023
Messages
42
Reaction score
13
Dear people of the internet

I've owned this casio keyboard for a while now and it used to be from my father. The pin that is found on the jack in the back of the keyboard was broken off and got stuck in the adapter ac plug. I was hesitant to repair the ac jack but after a few years of paying and playing on batteries i decided to order the same connector and a new adapter to try and fix my keyboard.

After soldering the new one in place and plugging in the adapter which has a specification of 12V, 1.5A and 18W of course it didn't turn on. (It's not because of sloppy soldering) I checked with a multimeter after plugging the adapter in and there seems to be 12V over the ac jack. There also seems to be 12V over the transformer. The diodes give a reading of 0.4V. I have limited electronics knowledge so i won't get any further than this. It's also not because the entire board is fried because the keyboard still works perfectly fine on batteries.

Is there anyone that could help with this problem or any solutions? I'd be happy for a solution that uses the dc connection from the batteries.

I'll leave the schematic for the keyboard below:


And my email if you want to contact me personally:

(e-mail address removed)
Your new adapter should have a DC output and not AC take care. The supply coming out should be direct current DC.

The supply input of your keyboard is not AC but DC meaning that one wire is + (plus) the other a - (minus).

Did you take care to the polarity (+ & -) when you soldered the DC plug to the adapter's cable? If you put the polarity wrong the keyboard won't power on. There is a protection diode inside the keyboard for this as else you would blow up the power inside and also possibly the main cpu board.

If you put the polarity right, check this on the plug you soldered with a multi meter set to the 20volts DC range it should read +12v.

Let me know should you be needing further help. I'm a retired technician now.
 
Last edited:
Joined
Dec 31, 2021
Messages
2
Reaction score
1
Not sure it this would work -
1- install 6 rechargeable D-batteries (not sure if NiCad or NiMH is best)
2- wire the jack directly to the batteries
3- plug the adapter to charge for short periods
no charging circuitry, so probably not safe to plug in long periods

If anyone has a better understanding of circuitry, please add comments.
 
Joined
Sep 19, 2023
Messages
42
Reaction score
13
Not sure it this would work -
1- install 6 rechargeable D-batteries (not sure if NiCad or NiMH is best)
2- wire the jack directly to the batteries
3- plug the adapter to charge for short periods
no charging circuitry, so probably not safe to plug in long periods

If anyone has a better understanding of circuitry, please add comments.
I wouldn't recommend this it is not as things should be for safe practice.
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Members online

Forum statistics

Threads
14,198
Messages
87,970
Members
13,220
Latest member
pcmtech

Latest Threads

Top