CTK-810 Turns Off Immediately After Turning On

[gjjude]

Hi,

 

I have a CTK-810 that is working fine for the past days. Just earlier, I noticed a mild spark noise when I used my keyboard connected through the adapter. After that, suddenly my keyboard won't turn on anymore. I re-plugged the adapter and tried to press the turn on button which causes the keyboard  to turn on just for one second but then turns off again. The cycle repeats every time I press the turn on button. I tried to put the batteries but same symptoms happen. I just bought the adapter recently and it's just 1 month old, so I'm sure this has nothing to do with it.

 

Do you have any ideas on what specific part of the keyboard to test? I don't want to scrap this keyboard because I think it's still working well and all keys are functional.

 

I have attached a short video of the issue. 

 

Thanks,

 

Jude

[- T -]

I am suspicious of your current problem occurring so soon after replacement of the power supply.  If the replacement power supply is not the exact model, specified by Casio, for the CTK-810, or if it is a third party "substitute" whose specifications do not exactly match those specified by Casio, for the CTK-810, then that new power supply could well be the exact cause for your current problem, especially if the voltage output of the new power supply exceeds the voltage input, specified by Casio, for the CTK-810.  Over-voltage applied to any circuit causes over-current within the circuit, and burns out the more delicate components. 

 

Whatever the cause, your current problem could be any one, or a number, of several hundred to several thousand components within the CTK-810.  Isolating the exact component(s) is quite near impossible for those who lack the proper tools, test equipment, and expertise, and at the age of the CTK-810, finding replacement parts could be very difficult.

[IanB]

As T said, this is an electronic fault that needs technical investigation. It sounds like some component burned out and the voltage regulator is shutting down due to detecting the consequent fault, but what precisely it is is a matter of electronics. If you are comfortable opening the keyboard up, the first thing to do would be a visual inspection under a bright light, preferably with a magnifying glass, to see if you can see any burned out components.

[Jokeyman123]

I would agree with T, most likely the power supply but could be something else more serious. And never use a supply that is the wrong polarity-Casios are generally tip negative but look at your CTK power specs and the supply specs. This can definitely cause a major problem. Even if the voltages match-there might not be enough "juice" measured in amps to power up the CTK. check how many amps the original power supply is. If your new one is less, it may cause this power off problem. if the voltage is the same-but the amps are more-are higher, that would be ok as the supply would only draw as much current (AMPS) as the CTK needs, although I'd feel more comfortable not doing that. use the same Casio supply if you aren't already as T said. and if you can, if you know how to work a multimeter-check the power supply wall-wart voltage at the barrel plug-see what the actual voltage is there-could be a defective supply.

[IanB]

My best speculative guess is a tantalum capacitor blew somewhere, and the voltage regulator is shutting down automatically because it's detecting the short circuit.

 

*Edit*

When you said you "put the batteries" can I take it you've tried running the keyboard on ONLY batteries?

[gjjude]

Yes, I did try running the keyboard on batteries only, but the same issue occurred. I did use a third party substitute adapter, because here in my area the original AD-5 adapter from Casio is hard to find. If indeed the adapter had an overvoltage, I'm just not sure why it happened so randomly when it was working fine for the past month. 

 

I''ll try the suggestions for basic checking with multimeter and visual inspection. 

 

Thanks!

[Jokeyman123]

IanB could be right. if you heard a "spark" sound-something blew. Caps make a sound if these short suddenly-look for one that might be slightly "swelled", sometimes a blown cap looks perfect but sometimes it might also have a slight yellow or brown top if its an electrolytic with a metal end. Your best bet is a cap tester-not very expensive-looks like a multimeter. I have a small one-since a multimeter can't always find a blown cap-it might be able to pass current or not-but  a cap tester can show you whether it is storing and releasing its charge. Look up Youtube-there are a few videos showing how to test caps-a little trickier than checking resistors, continuity or even transistors. ICs-not much you can do except to check the voltage (VCC) pins to make sure the IC is getting the correct power, unless you have a signal tracer-an oscilloscope that can show logic signals for individual pins-even then if the chip is defective-need to replace with its exact counterpart if you can find one. op-amps are easier to find, if it is not a specialized low noise chip-I don't think this Casio uses any of those, and these can also blow, and could have something to do with the sound generation circuits if there are any in this board. But more likely a cap.