Musical Keyboard PCB Repair
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- เผยแพร่เมื่อ 16 ก.ค. 2024
- A small repair to a keyboard with a damaged PCB.
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"On the bottom theres nothing, on the top theres even less" Priceless.
interesting points ,if anyone else trying to find out
car electronics repair
try Saankramer Electronic Magazine System (just google it ) ? Ive heard some incredible things about it and my work buddy got cool results with it
You’ve got an organ behind you and you relied on the keyboard demo button to show it was working? I was hoping you were going to bash us out a choon or two!
Same here give us a wee tune on the Hammond L-102 please, pretty please, JJW
Me too! I was very disappointed.
Failure mode is fairly obvious. It's a progression.
Dry joint on power connector deteriorates. Eventually it reaches the point where it goes high resistance/open circuit.
User finds that unplugging and replugging the power connector gives a temporary fix.
User keeps unplugging/replugging until one day it doesn't fix the problem.
User then applies excessive force. Which fixes things for a while.
Increasing amounts of force are required for a fix until one day mechanical failures mean the circuit board is floating and force can no longer be applied.
Ask JW to fix it.
When repairing the broken-off posts, there is an easier way than epoxy. Use Super Glue and Corn Flour. Make a small mould using cardboard. Wipe surface with Activator, then place mould around the pillar. Sprinkle the corn flour, add drops of Super Glue. Fixed. Works with almost any fine power, eg: Baby Powder, Baking Soda (the white stuff used for cooking).To make black, use course sandpaper on inside of object to create a large amount of plastic dust. Pile it up around the pillar and add Super Glue drops. This is instant and far easier than Epoxy (plus it actually sticks to plastics, providing you rough up the surface and use activator / accelerator.
18:45 that shows that you have respect for your work and for the machine itself. Well done !
As we used to say in a computer firm I worked for "bigger the blob, better the job" :)
Did that happen to be in the land of Canuckistan?
Great job JW. This video surely did bring back lots of memories as related with all the keyboards I did repairs on in the past. About 30 of such repairs as in the video. Very Common Breakage in both consumer and pro gear where keyboards/drum machines/laptops and such devices, sits on a table or stand, someone walks by and trips on external power cord, all comes crashing down. The first thing that usually breaks is the external DC input coaxial power connector where a hair-line crack happens between the jack pins and the PC board. Such crack(s) under the solder pad(s) is often not easy seen unless the jack is loose, moved showing the issue. When the jack is not loose, its more difficult to see any such fractured connections. Fixed by not just re-soldering but scraping off the surrendering PC trace area solder resist, exposing the copper, then soldering handles not only connection fix but even adds a better base mounting the the jack in all future tugs the external power cable. Of course in more serious damaged PCB repairs, as in video, jumpers have to be added.
that's exactly what happened to mine. the pcb is broken in an area one square inch around where the adapter plugs in.
Not difficult is it, common sense, a bit of know how and confidence. Thanks John, great video.
Thanks JW for the info about the types of glue you used and how to apply them.
"...at the consul of this mighty machine, and giving his own rendition and interpretation of 'Fly me to Dunoon' we have the ever popular, John 'the organist entertains' Ward, live from Blackpool Tower Ballroom in all it's actuality" :)
nice repair, I enjoy videos like this!
Thank you so much for your video. It gave my keyboard a new life.
Well done good repair job!
I wanted to share with you, these DC sockets that switch internally when the adaptor plug is inserted
Can get really oxidised, usually the internal switch acts to switch between 2 neutrals, but occasionally the layout is different and You Don't Want That To Happen!
So it's worth soaking the socket overnight use a blue tack well to keep the solvent in and later check continuity in all situations!
Kind regards Warren
New 2.1 or 2.5mm DC jack sockets are cheap so I prefer to fit new. The Sinclair Spectrum personal computers of the 1980's used the same type of socket and they would often wear out.
That was fun and it is always satisfying to repair something for not much effort or cost.:-)
Another great video, John. I think you should use that demo track as your channel theme.
You are a very clever man john....come to my garden bar for a beer
The solder joint under the first one you did, looks a bit dry.
brilliant video, nice job....
probably dropped while power plugged in (point of impact is power) - force breaks circuit board and breaks already weak dc jack
Hi John, I have a keyboard with a sound fault. The right channel works fine (both through the speakers and headphones) but the left has a bit of a hum and the sound coming from it is very faint. I was wondering whether you have any ideas. Thanks.
The DC jack on a Casio I was given seems especially weak. It looks like I'll have to take it apart and see what the issue is.
I can see how the text ended up backwards. PCB design software shows you a top down "x-ray" view down through the layers of the board, so anything on the bottom will look backwards. Whoever was designing this presumably didn't know this and "fixed" the text so that it looked correct in the editor.
I did my first repair solder style today - left it late at over 50 but hey, you can't rush a craftsman.
Margarita Pracatan will be back playing shortly :)
Have a thumbs up. I don't think many will get that
Hmmm the kids may have been using the keyboard as a stool.
my psr sx 900 Keyboad display has gone? what to do?
How do we mend one which stopped working and wont even work on batteries pls?Thanks
When you connect the power adapter ,the batteries, if they're inside the keyboard are usually disconnected. There should n't be a need to remove them.
I've been trying to learn that song you play at 0:43 so many talents!
TEA2025 sure seems familiar. Remember ISA soundcards in mid 90ies? Remember that they often included a speaker amplifier, and not just a line output, and you'd plug little beige shitty passive speakers in there? Well that's one of the ICs they used most frequently for that. It doesn't sound good at all with pronounced crossover distortion and is very cheap, but it's par for the course if your speakers are of that kind of quality.
Hi John I have a technics pr903 it internittently cuts out been told main board ? Can it be fixed ? Thank you
Psr s670 tempo adjusting itself when playing. How can this be solved?
Before taking it apart did you test the power adapter to make sure that it was supplying the correct voltage ?
or is common the case, the wrong polarity, yamaha and casio never could agree
Yes, that was the first thing checked.
is that voltage usually going to be 9 volts or 12 volts?
You left the dry joins on the mic, earphone and the audio amplifier not fixed as well, it will be back with poor phone audio and no mic soon. For the pillars I prefer to use Pratley putty afterwards instead of the epoxy, as the putty has a lot more volume to make the post fill a more robust block, and also I take the plastic and either sand it with coarse sandpaper or simply abrade it with a blade to make a rough surface to mechanically bond the putty to the plastic, as otherwise the epoxy bond to the remains of the mould release are poor, and breaks with time. If no putty around some fine sand, dry talc, or even clean cat litter works fine as a bulking agent for the epoxy mix, so you have a large volume of material with low cost making the join very strong.
JW - How did you manage to not super-glue your fingers to the pc board or the standoffs? No matter how careful I am I always seem to do that 😕
Always use latex gloves when handling glues - especially bondo's and cement types. that way you don't wind up having to go to the emergency room. always use caution when using Gorilla glues
JW does 8 bit keys
I was thinking that :). But JW did not do a multi track recording at the end :(
Ooh, I would have love to see that
8 Bit Keys does look at cheap keyboards, but this awful unbranded thing would be way below his standards!
Ideally the old solder should have been removed, the pads cleaned up, some fresh flux and re-flow the connections. just loading it up with more solder is a bit sloppy. However a partial save on an cheep and cheerful keyboard.
surprised you didnt play it
Just use the battery leads to wire your jack two minute fix.
fly me to the moon!
Seeing how circuit board are started from a peice of copper. Than etched , leaves me confused to a peice of copper? Because the circuit itself is protected by tracing paper, than is dipped in acid solution. Making everything but the circuit, a breaker board. Just seems, to unbelievable. So need more clarity to circuit board engineering. Along with many other factory process, programming, for better sound in this case.
Circuit board does NOT start as a piece of copper, it starts as a copper clad board, either FR-2 (phenol-impregnated hard paper) or FR-4 (glass fiber epoxy composite) that a very thin sheet of copper is glued onto with epoxy. The copper clad board is coated in ink that protects what will later be traces, dipped into acid, and pieces of copper sheet not protected by the ink are dissolved in the acid (copper will be recovered from acid and reused later). Finally, the ink is washed off, the copper is plated over with tin to stave off corrosion and provide easy to solder surface, and (usually green) lacquer can be applied for protection and (usually white) lettering printed on top.
For applying the protective ink, the lacquer, and the lettering, usually the very same process is used, they use lacquer and ink compositions that become hard under UV light, so they cover the board with the liquid, shield the areas that shouldn't be covered with a mask, such as a photographic transparency, shine the light for a couple minutes, and wash the unhardened liquid off.
As to the engineering on this particular unit, it's mostly the "no shits given" school of thought. Whatever cheap leftover components they could find, whatever they could get away with while applying the least amount of highly paid engineering force. The second most common school of thought, successfully practised by larger manufacturers is "we know how to do things well, but we'll tend to err on the side of excessively cheap rather than somewhat good", they might after all make millions of these things, and every penny saved pads their bottom line by tens of thousands.
I have a keyboard like this, but it seems the socket thing that the USB cord plugs into is messed up. Like it doesn't make full contact, sometimes turns on if you jiggle it, or hold it at a funny angle, but no luck otherwise. Any suggestions?
moonasha try a different USB cord first of all. Otherwise like here, the socket could have a loose connection inside and needs the electrical connection to the board checking.
it'snot the cable, tried more than one. I don't think it's the socket's connection either, since I dont have to push on it. I think it's the actual gold contacts, or whatever metal they use. I think they just got worn down... don't know how to remedy that
moonasha hmmm. Not sure. If the socket itself has some corrosion on the contacts then it can be removed with a scrapy thing and paint thinners, if it's just worn out generally then you should be able to find a replacement socket on eBay really cheap, it may be the case you'd need to desolder the old one from the board to put a new one if you fancy that, or, run some wires from the new socket to where the old one meets the board. USB has 4 wires but if it's only power you need it's usually red and black all you need.
Surely the new theme tune for the channel ! Good job as ever John
Well I'd open the case and have a look at the board where the power connector is attached - you often get terrific stress concentrations where connectors to the outside world are soldered to circuit boards and it's a frequent point of failure. Could be cracked solder joint, cracked circuit board or copper track pulled off the circuit board.
Hi, great videos! I have a broken Roland RS-9. I have recorded the issue on my TH-cam. If you dont mind have a look and let me know what you think. Thanks!
Sir How to repair music key boards totali dad no display sow plz help me
Fakeo pieces. 😂😂
Good content but oh that soleless voice