casio pk-1 resurrected

[jamiewoody]

i thought i had fried this keyboard or something. lol! i set it aside for about 6 months.

one day, i just took it out and made a wall wart jack for it. then i turned it on (of course, no status LED, to see if it was on at all_.

i took a rubber handle screwdriver and started poking around everywhere. i got to the bigger chip, and with the screwdriver, connected 2 pins and VIOLA! it worked!

i have no idea WHY this made it work, but it worked. so, i soldered a jumper to the 2 pins.

so, i guess rule one in troubleshooting, don't look for the "why"...just start tring things. (of course learning theory is good. who would have thought anti-theory could actually FIX something??!_)

[electoyd]

discharging the capacitors is always a good way to start the troubleshooting, i have resurrected many machines doing that.  When troubleshooting i would say it is better to have a system rather than just randomly poking about hoping for the best, which can work (in your case) but i certainly wouldn't be doing that to any machine i cared about, get the multi meter out or you could do alot more damage than good otherwise.  But i work on studio stuff and i know you prefer the smaller SA's and the likes which are easier to part with if they break/fry.

[jamiewoody]

thanks for the words of wisdom.

my last post is coming from the perspective of learning as i go. i had sort of cast that keyboard away, thinking i would not get anything else out of it. the poking around was a last resort. but, seemed to do the trick. i have no idea why installing a jumper between 2 i.c. pins saved that pk1. 

especially good advice on discharging caps! could be life saving advice even!

i am sure the studio stuff you work on is more expensive and higher voltage.

i really need to take a class in metering and troubleshooting.

[Ciderfeks]

i really need to take a class in metering and troubleshooting.

I hear you on that one Jamie! Me too.

[jamiewoody]

something a friend of mine who went to electronics school told me,while troubleshooting, "always look for the obvious first". even before taking out a meter, etc, turn it on, flip the power switch back and forth a couple of times, etc. it could be a simple fix which only looks hard.

[casio]

Hello Jamie-

I've not seen this keyboard before I scored one either -and glad you got yours working.

Mine was broken open -with all the screw pins [less one] attached to nothing but the screws themself.
the buttons where all inside the case i could see -and for .50¢ I couldn't pass it up.

well I put it all back together -and taped the case shut -and it worked! I was stoked -LOVE the sound this
little gem makes.

I was wondering -because I don't see in either post -if you'd hooked up an output. When I opened the case
to repair the li'l guy -I noticed there was on the board -a spot for power supply -and output -that casio never
utilized. I've messed around with it a bit -yet was wondering if you could give me any time saving input on the matter.

Thanx-