Circuitbenders Forum
Circuitbenders Forum => Circuitbending discussion => Synths & Samplers => Topic started by: dimefan90 on August 18, 2009, 05:16:31 PM
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my casio sa-9 had 2 bends that i had done, feedback and voltage crash. tonight i decided i wanted to add a couple more. i wired everything up for the deep crash and high pass filter.
when i closed everything up and turned on the keyboard.........nothing.
i checked the batterys, then removed the bends i had just done.
still would not turn on....
i was becoming quite upset and frustrated at this point.
turns out i have bridged 2 of the pins on the larger chip. i have tried to undo them but there is still some solder left deep between them
i havent got any desoldering braid or a sucker, would these help? because i really want to fix it,
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Heat it up and then BLOW REALLY HARD on it away from the pins or tap it on the worktop. Works for me in times of panic and emergency. It's very crude but has saved me a number of times :o
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you could always take the whole chip off, clean it up and resolder it. Although you'd probably need solder wick and a solder sucker to do that proper;y anyway.
In fact, both those things are essential tools anyway. Go no further until you have bought both! :)
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i went out and bought some desoldering braid, a solder sucker and a multimeter. came home and had a go at getting the solder from between the pins. i turned on the keyboard and only every second key would play. so i opened her back up and looked for any solder i had missed. none that was obvious.
i then notice that in all the commotion i had broken one of the tiny wires on the speaker terminals, no big deal i will just resolder it.
I SNAPPED THE TERMINAL.
how do i fix that. and does anyone know why the keyboard isnt working because i have no idea.
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"carefully" ;-)
You can't superglue it, because superglue gives off incredibly unpleasant fumes when soldered. Now, how you go about fixing it depends on a few things.
You need to make sure you don't pull the thin flexible wire off the back of the speaker cone, and you need to make sure that when you repair the speaker the wire is free to move. What I'd do there is solder a nice long wire to each tag, glue the snapped-off tag back in and carefully tywrap the long wires to either the speaker frame or the magnet.
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i sorta get what you mean. but all that would be useless unless i can find out why the keyboard wont work. when i turn it on i hear a click, but nothing works.
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ok, i fixed the speaker, and i rewired the keyboard for the feedback bend. that part works, this thing scream like a bitch. but the actual keyboard buttons and keys dont work. could i have fried the chip.
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if its a few keys not working i'd have another look at the chip mate - as you may still have a short there...
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well it is no longer working at all. no keys play
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make sure the feedback isnt right at the top of the range and also if you've done the battery drain (check the pot) or deep crash check those - its actually very hard to kill these keyboards hopefully it'll be okay...
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what do you mean top of the range?
could someone post a photo of the green side of the circuit board of a sa-1 -7 or -9 when i was taking the solder off the chip i de soldered a bridge that was supposed to be there. and i don't know which pins it was on.
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what do you mean top of the range?
could someone post a photo of the green side of the circuit board of a sa-1 -7 or -9 when i was taking the solder off the chip i de soldered a bridge that was supposed to be there. and i don't know which pins it was on.
(http://blog.makezine.com/casioSA-bendingMap_cc.jpg)
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i meant the other side. (green)
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i have found out what is wrong. the metal pads that the IC's pins solder onto have come off and now the solder wont stick.
what can i do to replace these
not my picture but it shows the part i am talking about.
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If the solder pads have come off completely just take a wire directly from the IC pin to wherever it was meant to connect to. On a single sided board like the SA's this should be a simple matter of just following the circuit tracks from the IC pin to wherever they were meant to go.
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thanks, i was thinking. is there some sort of metallic paint that i can put in place of the pads?
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You can get silver conductive paint that you can use to repair circuitboard tracks but i don't think you can solder to it and its not cheap for how little you get. I'd go with the bridging it with wire technique.
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ok. so i have all the buttons working and most of the keys, but the last 12 wo'nt work because i can really find where to solder them.
it would have only been the last 4-5 but i accidentally cut the track for the other 8 while looking for a solder point.
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how do i repair a track. i scratched one of them and now it is broken.
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Scratch off the green overlay on both sides of the break to expose the copper track itself and then just either try to put some solder across the gap or get some thin metal like the cut off leg of a resistor, and solder it to the exposed copper on either side of the break.
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If the solder pads have come off completely just take a wire directly from the IC pin to wherever it was meant to connect to. On a single sided board like the SA's this should be a simple matter of just following the circuit tracks from the IC pin to wherever they were meant to go.
Sometimes you dont even need to find where it goes, just scratch off a small square of green thats covering the track up and solder to that