Casio WK-1630 No Power Problem. HELP!

[redrider123463]

Hey people,

Anyway let me get straight to the point. I have a Casio WK-1630 keyboard A.K.A Radioshack MD-1700 (which is what i really have)(yes i know its old) and when i plug in the AC adapter and press the power button nothing happens. So i figured it was something on the inside, so about 30 screws later i open it up, and i see what looks to be a blown fuse (i think)

(Crappy phone pictures, sorry) so then i proceeded to pull it out, and it then looks like THIS.

Which looks like a blow fuse to me, but i have no idea what i am doing, it was a 3 prong plug thing, but one was so toasted it broke off, so now what can i do about this, because it burnt off the gap between 2 of the places to put the 3 prongs?

HELP ME!!

 

[DickR]

Pictures are too bad to really see what it is but it is NOT a fuse as far as I can see. It looks like a thyristor (sp) or something. If it is still readable there should be a code on it in numbers and letters.
Replacing it does not guarantee a proper working again. You have to find out what made it blow. If you don't know what you're doing, DON'T do it yourself. Seek help of a qualified person with the right tools. You might ruin more if you fiddle around.

 

[redrider123463]

There was a code around the burnt part of the board that said D203, there was nothing on the piece I pulled out. Where could I get a new one of these things?

 

[DickR]

BTW the burnt away piece on the board can be overruled with small pieces of wire being soldert on the 'tracks' on the board. The 'thing' whatever it is doesn't need to sit straight on the board.

 

[DickR]

D normally stands for Diode, it could be a part of the powersupply to make DC from AC. They can get very hot and often have a cooling-thing- on it.
That sounds correct to me if the power doesn't work anymore.
These parts are normally sold in shops with electronic supplies for, by example, radio-amateurs. But again let someone look at it who is skilled in this stuff.

 

[YeahDoIt]

List of parts here:

http://support.radioshack.com/support_games/doc60/60917.htm

D203,D211 12292934 DIODE SB20-03B TO126VAR T DX90174

You might purchase another diode from Radio Shack, install it, power up and notice if it explodes.

If you have a meter then check the resistance of that big capacitor. If the capacitor is a short circuit then it might draw so much current that the diode explodes.

 

[DickR]

Sorry YeaDoIt, I wouldn't just replace it and see if it explodes. If it keeps going even for a second before it 'explodes' you can ruin a hell of a lot more. The best advice is to find out why it did what it did. Of course it is possible, only if you are lucky, that it burnt it's footing away due to a bad soldering. But who can tell you are lucky? I wouldn't take that risk with my keyboard.
Redrider said 'I don't know what I'm doing' so I advice to have a pro have a look at it.

 

[William]

That diode (YeahDOIT diode ) appears to steer voltage from either plug-in adapter or batteries. I have a similar problem with my OPTUMUS (radio shack 42-4034) Keyboard.
I would try a new device and try to measure current draw with a meter. The device handles 2A at Vf= 0.55v so you should not see more than that on your meter.If you do look for a blown electrolytic cap (top of the can is no longer shiny) on your circuit board or some other discoloration that that indicate a blown part due to the smoke demon leaving.

Here is the datasheet (for YeahDoit diode)..
http://www.datasheetcatalog.org/datasheet/sanyo/ds_pdf_e/SB20-03B.pdf

The pin blown off is the anode, the midle pin is the cathode and the last pin is no contact.

Problem is that this device can not be purchased anywhere that I can find. Any luck getting it from RS?

I have used the Digikey search to match a similar device in terms of electrical parameters. (I0 = 2.0A. Vf = 550mV Vr = 30v.
I have found an electrical match but no match wrt. package. SS2P3-M3/84A is the part I am ordering from Digikey to replace in my keyboard. Just that is is a surface mount device so I will need to glue it down on its back and wire to the pads w/ short jumper wires.

In your case I would leave the cathode end un-connected and measure current through a meter to see if you still have a short elsewhere and how much. Probably you do or it completely burned itself out. Surprises me that you circuit is not fuse protected.

 

[William]

my circuit looks something like:

+ ----------coil winding -------------------------------------------------------------------------|12v adapter |​

- ----------coil winding-----------DIODE------------------------------------------ |C A | |​

| |
+ -------- fuse------------------------------------------------Diode------------------|------------O----------CIRCUIT POWER
9v battery A C |
- --------- fuse--------------------------------------------------------------------------O------------------------ CIRCUIT GROUND

Where DIODE in both cases are the same part number as the YeahDoit part. SB20-03B.

Woops it did not draw correctly, You may need to slide text around to get things lined up

 

[William]

schematic is here:

http://www.youtube.com/user/MrBoriswart?feature=mhee