Synth-DIY Yahoo! Groups Archives

Well, a "good" electronics repair person should be able to fix anything. Basically, they don't want to be bothered.

The first thing I would do is check for voltage. Use the multi-meter on "DC voltage" setting. Check your AC adapter first, to make sure it's putting out the required 9V with the correct polarity (I think it's center pin = negative). DO NOT USE ANYTHING HIGHER! Next, plug it in and start checking the connections inside the unit to see where you have voltage and where you don't. OR, use battery power and do the same thing (= safer). Tracking down the voltage will probably lead you to the problem. Don't worry about testing the capacitors, resistors, etc. yet. You can't really test components properly unless you remove them from the circuit. No, you don't need a static mat.

If the power plug was the problem, it would most likely still work ok on batteries. Again, you test for voltage at the power plug contacts inside the unit, then follow the traces. If you're getting voltage in there, the plug connection is ok.

You may be able to use your 15W soldering iron. For small components like the transistor, you don't want much heat at all - too much will fry it. (The RCA cables you were trying to solder were probably much thicker wire and required more heat.) The other thing is, you want a small tip on the iron to do fine work. Ideally, you want an adjustable temperature Solder Station with an iron that has a variety of replaceable tips. I have the Weller WES51 (<http://www.amazon.com/Weller-WES51-Analog-Soldering-Station/dp/B000BRC2XU>). Pricey, but again, it depends on how much you plan on using it in the future. This puppy will last a lifetime. There are many, many shapes and sizes of tips available for it.

I also recommend an Edysn Soldapullt for de-soldering work: <http://www.edsyn.com/index.php?Mode=piw&pn=DS017>. Another GREAT tool.

As far as WHERE my burnt transistor was... unfortunately, it's been a while since I had my HT6000 apart, and I'm not able do do it again right now... BUT, I did write up a little something when I did it. Here's what I have (see below). I don't remember if I actually took any photos or not, but I'll look around and see. Hope this is somewhat helpful:

CASIO HT6000 Disassembly

Looking down into the bottom of the Keyboard, keys away from you, "Casio" logo facing you but upside down:

1. Remove all of the screws in the bottom piece. Before removing the bottom completely from the keyboard, you'll need to unsolder the white-sleeved ground wire from the board on the left, near the screw, AND unsolder the 2 white-sleeved battery wires from the board on the right - Left is RED, Right is BLACK. Remove the zip tie through the hole in the board securing the wires.

You'll also need to unscrew the Card Reader, so it's loose.

2. Disconnect the gray ribbon cable connector from the left side of the left top board. Remember, or write down, how the cable runs underneath, so you can put it back correctly.

Remove the 6 screws in the right board - Mark or remember that the larger one goes into the plastic riser post.

Remove the 6 screws in the left board - Mark or remember that the 3 larger ones go into the plastic riser posts.

Move the 2 top boards out of the way.

3. Unscrew and move the 3 Keyswitch boards out of the way: There are 12 screws in the left board, 6 screws in the middle board, and 10 screws in the right board. Remove them all.

4. Remove the 9 screws in the 'Output board' and move it out of the way.

5. Remove the 5 screws thru the 'Foil board,' which is covering the 'Power board,' and remove the 'Foil board'.

6. Remove the remaining 6 screws in the 'Power board'. There are slider controls that go thru the keyboard body on the left side - remove those knobs, and then you can lift up the 'Power board'.

7. The transistor which burned out on mine is on the right-side of the board. It's a very small black vertical rectangular piece with 3 legs (connections). It says "B1117" on it. The board was black all around it in a circular pattern where the heat burned it.

Good luck! Let me know if you need more help. If you send photos of your progress, maybe I can help guide you.

-Tom

On Tue, Dec 31, 2013 at 12:13 PM, david w <therealdjdub@...> wrote:

yea my problem with repair guys is the ones i've called act like its somethin that they have no knowledge on being that its music gear, i keep gettin told "i dont know anything about keyboards" or "thats not somethin i do" ????? i thought electronics repair was electronics repair all the same, guess not though......so if my problem ISNT the transistor, would a multi meter have to be used to test every little capacitor resistor etc, do i need to test this while plugged in even though im gettin no power, and if so, do i neet a static mat?, and i guess my last question would be, what if its the power plug on the unit?, if thats the problem would it be burnt up or anything like that, any way to test that?....oh also what would be the best soldering iron to grab........i think i have a 15 watt one layin around, but last time i used it it didnt seem to get hot enough, used it to re-solder rca cables on a turntable, and it was a nightmare, so maybe i have a P.O.S solder gun...............anyway thanks for the help so far.....really dont wanna throw my ht away :(

Casio Collectors

Re: [casiocollectors] ht6000 question

Attachments

Move to quarantaine