Electronic Piano Missing Notes Fixed also MIDI Reset Problem

[@frundlemud]

You certainly do not come under the have a go tribe that hang out here. Excellent lesson with a full understanding of the electronics and how to diagnose and repair.

[@mcentertain]

You are a great guy I learned a lot. Appreciate your calm steady voice and your gap-less way of problem search, you are a master! THANKS

[@Pizzarules]

THANK YOU SO MUCH! I have a fussy korg and have been losing my mind in search of a clear and easy to follow video!

[@sonex413]

You are so welcome!

[@jimhoffmann2649]

Mike, thank you for covering this note troubleshooting in depth, and answering questions. Gives me confidence to try to fix bad key on very old model Roland hp-2500s for my church keyboard. Because it is so old, I don't want to pay shop rates to try to fix it... Trying not to scrap it either. Repairing out of my own pocket. Really appreciate it ! - Jim

[@sonex413]

I hope you succeed and that this video was helpful! Thanks!

[@jimhoffmann2649]

@@sonex413 Hi Mike! Success! I fixed the bad key myself. I am happy. It helped to see your video. I ended up making a little homemade tool to release the spring on the key so I did not take entire keyboard out just the affected key. Your video helped me figure out how it should come apart and how to shape the tool. There was a tiny speck of dirt under the Silicone touch strip. Cleaned it and it worked fine afterward. Only other problem is sometimes after removing headphone jack, the sound does not reliably come back on thru speakers. Maybe loose or dirty connector inside female jack assembly? I might just get it working and then block off the jack. It is a nuisance. Any experience with that problem? Have a great week. -- Jim

[@sonex413]

@@jimhoffmann2649 Nice work, Jim! Yes, it sounds like a faulty contact in the headphone jack. Clean and possibly tweak the contact leaf so it makes a little firmer contact with the headphones unplugged. Have fun playing that missing F sharp or whatever it was! Stay safe and healthy. -Mike

[@johnbell913]

Very good electronic lessons. Thank you so much.

[@michaelj.geogheganjr.3608]

Do you have any images of the jumper you soldered in place? Great video, thanks so much!

[@sonex413]

Hi, it's the white wire visible in the video if you jump to 22:14 Glad you enjoyed the video, thanks!! -Mike

[@TH-ql3op]

This is an amazing video, very useful, thanks. one question please How to fix one of the diodes not functioning?

[@sonex413]

See my other reply and good luck....

[@seattlesoundproductions3492]

Thanks for the video! This has helped me narrow down the issue I'm having with an HP-3100e, where every 8th semitone (starting with low Bb) does not work. I've found a service manual for this keyboard, but no owners manual (go figure). All of the diodes check out as do traces on the lower key bed (haven't looked at the top yet). I've cleaned all the contacts, but still no joy.

[@tfentecott]

I'm having a similar problem, did you get anywhere with this?

[@jfboulanger5368]

Hi, This is exactly what I am looking for (I have 2 dead notes on my HP800): thank you so much. However, I am still looking for information on how to remove the the keys to get at the boards. From your video it looks like they are all assembled onto one 'frame'. I have yet to find the service manual for this model, so any information you may have on this would be greatly appreciated. Francois.

[@robadlers6668]

Thanks so much for this video! I acquired a HP-5500s, and two lower notes are not responding to contact. Will check the diodes and traces.

[@sonex413]

Hope you find the problem!

[@tomsmyth4836]

Mike thank you so much. Would an alcohol clean work on the contacts and the contact silicon connections?

[@sonex413]

Hi Tom, Alcohol will work on the contacts of the printed circuit board. It would probably work on the silicone parts as well, but I'd make sure it doesn't attack the material first. The keyboard we fixed in the video is still working. Thanks for watching, hope you get your unit cleaned up OK. -Mike

[@number661]

Hello. Thanks. Im trying to repair a dead key and pulled out the contact strips for cleaning. I wasnt paying close enough attention and did not know that the contacts are as you point out at two different heights for velocity. Now im unsure if the higher contact is at the top or the bottom. Tried using logic and trial and error but still unsure. Please help. Thanks again.

[@sonex413]

Although the principle of operation is similar throughout many keyboard brands, the details of mechanical construction are often quite different. I would try installing one way and trying it. If you have it wrong the two contacts will close simultaneously and trigger a maximum volume note. If that happens, swap it around. Good luck!

[@number661]

@@sonex413 Hello. Thank you for taking the time to reply. Yes i tried both ways and hmm?. I'll keep at it. Anyway thanks again and i'm glad i found your channel.

[@timnordberg7204]

@@number661 the contact strips I have seen have triangular divots cut into them. if yours have these, look for a painted line on the pcb around area they attach to, with corresponding divots. aligning the divots will make sure your contact strips are oriented correctly.

[@Danquahdee]

Please when i press 1 note (for example C5) it seems to trigger about four or five notes around it, it happens on G or F (can't remember which) as well. 4 drum pads seem to be constantly lit as well and these trigger too when i press those keys. I've tried everything from resetting the oxygen 25 to resetting FL Studio, nothing seems to work! It's driving me insane! It used to work fine and now all of a sudden its developed this problem over the last few months. Please help

[@121five]

Thanks dude, awesome info!

[@leonarddobrzyn725]

Great clip... Hope you can see this and answer. I was told never clean the boards or rubber strips because you will clean off the graphite and destroy them. Any validity to this?

[@sonex413]

If they are dirty enough to cause a problem they need to be cleaned. I suggest being very gentle.....

[@williammchugh4361]

Ugg, I have a Korg that got something spilled on it. After thoroughly cleaning it out, had 1 key that didn’t play. Replaced a diode in this circuit then found out with extreme backlighting and magnification that the trace right at the detection pad seems to be broken (with a gap?) These newer korgs have built up black detection pads with the build up extending into the trace. it’s very difficult to see any breaks without strong backlight. I haven’t decided how I’m going to fix this, obviously a jumper wire is out. Likely going to be a scrap off and solder some type of junction in. But boy are these traces in the Korg tiny.

[@sonex413]

Good work diagnosing the fault. Never know what you're gonna find!

[@williammchugh4361]

@@sonex413 That black build up was the carbon patch. I didn't realize these newer Korgs do not have copper in the detector. I'm going to have to use conductive paint.

[@tzvistroh8515]

Thank you. I was able to fix my Yamaha psr-e443 using your instructions.

[@sonex413]

Glad it helped! I appreciate the feedback.

[@GD-he2xj]

Great video, thanks. I have a few keys not working, and will check as you advise. I have another more concerning issue - all of a sudden my volume is at Max, and there is no way to turn it down. Any common scenario(s) that might cause that? Thank you!!

[@sonex413]

You're welcome! Sorry I can't help with the volume issue other than maybe check the volume control potentiometer.

[@perpetuant5452]

How do you fix the actual traces on the circuit board the key pads/contacts hammer on or touch?

[@sonex413]

I have not seen those contacts get worn out, usually they just need to be cleaned, but if the contacts are worn off you would need to apply some sort of conductive coating. I'm not sure if it's still being produced, but I recall a product which was like a copper paint...you could paint a conductive trace with it on a circuit board. Maybe something like that could work. Good luck!

[@YooTooobJeff]

It's funny that those rubber contact strips are made precisely to shield the contact surface from dust and dirt! Usually spilled coffee etc is the thing that can sneak under the edges and interfere with the contact interfaces...

[@sonex413]

Yes! I just replaced my computer keyboard when I couldn't clean it....due to some Doctor Pepper...

[@godwintorres2251]

Thank u dude for the help. Roland 3000 same problem

[@sonex413]

You're welcome! Hope you get the Roland sorted out.

[@godwintorres2251]

@@sonex413 now playing more power to u !

[@AshleyAlvares]

Good video Mike. I got most of my keys on the digital piano working. But there are a few that play very loud when the keyboard is just turned on and then in a few seconds later they go dead. Could the problem be with diodes related to the keys? Would you know what type of diodes are they typically? Many thanks. :)

[@sonex413]

Hi, thanks for the question. Let's break it down: The fact that there are a few keys acting up probably points to something those particular keys have in common. You could trace the circuit paths back from those keys' contacts back through the copper circuit board paths and see if they all end up at the same diode, or perhaps all lead to a point where the paths are bridged, like a short circuit. You could also just check all the diodes associated with the problem keys. You can find info on checking diodes with a multimeter on line, don't forget that at least one leg of the diode must be disconnected from the circuit during testing so that you're not measuring back through some other components. On my piano I accomplished this by disconnecting the ribbon cable from the contact board to the main board. If one leg of the diode goes to an empty contact pad you're already there. As far as testing you will have the advantage of having lots of good diodes in the piano so you'll know what readings are normal. The good ones will look almost identical to each other on the multimeter. If any readings are way off the norm and you need to replace a diode, any fast acting silicon switching diode will work. I think I called them "plain vanilla" diodes in the video! A couple of popular ones are 1N4148 and 1N914. They are ubiquitous in almost any electronic device that has buttons or keys and in a pinch you could cannibalize a few from an old keyboard or something. I think new ones are about a nickel apiece, though, so maybe not worth that effort! Good luck, I hope this helps a little. Let me know how you do. PS subbed your channel. -Mike (edit for spelling)

[@AshleyAlvares]

@@sonex413 Thank you Mike for your very detailed explanation. I will investigate more and get back to you. Right now trying to source Hammer Caps for the keys.. as all of them have deteriorated over time. I will let you know how it all goes. :) have a great day!

[@TH-ql3op]

Hi Mike can you please show us how check, identify and replace a diode Please.....!!

[@sonex413]

Sure! Most multimeters have a "diode check" function. When you hook it up to a diode in one direction the diode will conduct current and the meter will beep. When you hook up the meter in the other direction the diode will not conduct and there will be no beep. I'm sure someone here on youtube must have a video all about it if this isn't clear enough. Likewise there are some great videos about desoldering and soldering circuit board components. Most important is to not damage the diode with excessive heat during soldering. Takes some practice. -Mike

[@TH-ql3op]

@@sonex413 Thanks Mike You're a gem

[@TH-ql3op]

Hi Mike, I have learnt to check the connections with multimeter, thanks heaps for your training. However, I have found that one of the key that wasn't working returns very high value/reading for the circuit covered under silicone than the other keys. For instance, other keys return a value of 034 , 041 etc but for the dead key one node returns 1086 and the other node 980 etc Would help me understand what the issue might be?

[@小月读书斋]

the problem with my piano is, serveral keys have no sound; and one key keeps sounding, cannot stop (if this key is ringing, none of other keys works). what could be the problem?

[@Angel-ve8pj]

My Piano is was wet and now is not working. What do I do?

[@sonex413]

Hi, if it was fresh water (not salt water) I would open up the case and let it sit in the sun and fresh air for a few days, then try it and hope for the best. Check the fuses if there are any, especially if the power was turned on when the water was spilled. I had a laptop computer which got wet and it worked after drying out, It took almost a week to dry thoroughly. Good luck, I hope your piano survives!

[@more.1000]

My Roland juno di keyboard get automatically detuned while I plays chords , Nots gest overlap

[@sonex413]

I had a Roland Juno many years ago, and I seem to remember it had some kind of "arpeggio" mode which made the notes behave differently....it was a long time ago but my thought is that maybe this mode has been turned on. Sorry I can't offer you anything more definitive on your problem, good luck. -Mike

[@irmabushell5712]

Well done, indeed! Thank you.

[@sonex413]

Thanks! I knew this one wouldn't get a lot of views but I was hoping it would help somebody! Appreciate the sub very much. -Mike

[@irmabushell5712]

I really appreciate your explanation about repairing circuit traces. I have an RD 250s and I feel more confident about getting sound from the dead keys. I've spent months searching for information. The basic cleaning of the contacts was not enough to solve the problem. Your tutorial is comprehensive and I'm thankful that you decided to share your knowledge. Very much appreciated!

[@sonex413]

Hope you find those missing notes. Go get 'em! Let us know how it goes too!

[@pauljacobsen864]

Thanks I had the rubber contact strip upside down ahh

[@519ctk]

Mike - I sent you a private message on facebook with a question.

[@sonex413]

Best to ask questions right here, I read all comments!

[@amerikanstafford]

+++++++++++++++

[@sonex413]

Many Thanks!