Circuit Board Problem, Damaged, Faulty Motherboard on Digital Piano, Synth Keyboard

Circuit Board Problem, Damaged, Faulty Motherboard on Digital Piano, Synth Keyboard
Question:
Hi I think that my Casio PL40r digital piano has a faulty motherboard. I am looking for someone to help me fix this or search for a replacement card. It can be used as well. I am also looking for someone who can send the motherboard, because the Casio in Japan does not want to send me a new motherboard. – Paul (italy)

Answers:
Does my Nord Electro 2 Synth keyboard have Circuit board problem? When I power the keyboard on, everything works fine. But once I start to play it, the keyboard freezes up. It will hold on to whatever sound I’m playing at the moment and I can’t get it to do anything else. I’ll press all the buttons on my Nord Electro 2 keyboard (even the volume knob) but I won’t get a response. Sometimes, the keyboard will just completely shut down. It sometimes takes only a few seconds to do this. Other times, I can play for several minutes before it shuts down/freezes up. Any suggestions for my Nord Electro 2 Synthesizer keyboard? – James Johnson

I have a Yamaha PSR-295 keyboard. It is about 5 years old, but rarely used. A couple of months ago, when I turned on the psr295, there was a “pop” sound, and the sound and programming failed to work. The display lights up, but there is no output and we can’t change any settings. I took the Yamaha psr-295 keyboard into a music shop and they said the main digital circuit board is faulty and needs to be replaced (cost > 325.00). Is it common for this part to break down, and what would be the cause? Is there a less expensive way to repair my Yamaha PSR-295 Keyboard? – Kathy

Our son tripped over the power cord for the electric music keyboard they use for piano practice at home. Somehow it loosened the inner piece that the cord plugs into on the keyboard. For a while they were able to get it to work by kind of “jiggling” the plug and if it was pushed up slightly, it would turn on. Otherwise, batteries were required. At some point, another child (we have five and one is two years old) knocked the keyboard off of the stand so it has also fallen. As a result even batteries do not power it up. I realize that the PA-130 is not a high-expense music keyboard and it is likely best to just purchase a new one, but that is money I do not have to spare right now and I’d really like to figure out how to fix it myself. Any tips would be appreciated. It is not hard to open and get to the motherboard and circuitry and I figure that it’s not working at this point *anyway* so I’m willing to take the chance and open her up. – Melissa Edens

I purchased a Yamaha digital piano about 8 yrs ago. It was used a minimal amount…about 8 months worth of piano lessons when it started acting up. After taking it to a repair shop and them keeping it for 3 months, they determined that a “Circuit Board/Chip was damaged”. They said Yamaha could repair it. It would cost me $300. Yamaha would only warranty the repairs for 90 days. Is 8 yrs really the expected life span of a $1200 Yamaha piano? Or should I take it to another repair shop for a second opinion? – Linda (United States)

New chip for your Yamaha digital piano will work another 8 years or much more, so don’t worry. $300 is high price for 15 mins of work to replace chip, but they charge a lot for labour. I can tell you, You can buy for $100-$150 same Yamaha piano which is 8-10 years old on ebay or some local sites. – Poc

I have a yamaha dx27 synth. When i turn it on it says welcome to dx but it keeps repeating it over and over again and wont do anthing else. I have checked and tested everything on the circuit board and it all seems good. Any ideas what it could be? Have another Yamaha ypp-15 with no power. I do not have a circuit diagram but have done some initial investigation on the mother board. Power is getting to this board but some component on the board has failed. There is a power transistor on the board which may be being used as a voltage regulator, it is a 2sd880, but I don’t know not having the circuit. Any help would be appreciated. – Wills

Suzuki hg500 Piano – Circuit Board Problem? My piano functions properly in every aspect – but no sound. I don’t have a whole lot of money to spend on repairs. Had a technician out – Amp and preamp work. He determined it was the motherboard. I want to find a new circuit board and install myself. I’m somewhat experienced w/ working on computers, radios etc. Seems like it should be the same. Good idea? Bad idea? Suggestions? – Melody (Tyler, TX, USA)

You could be able to do it yourself if you know how to fix computers. You’ll need to know the motherboard number to get the exact replacement though. The ribbon lead had a bad solder joint. I could not tell without a circuit tester. – Humphrey

Why do you want to attempt to repair / replace the motherboard. I think you should refer all your servicing to the dealer from where you bought your Roland HP 2900 G Digital Piano. Did you try getting in touch with Roland support on this? – Ben

I agree that all spare parts replacement, including motherboard, and repair related things should be addressed to Roland Service Centre. They will also supply you with service manuals. You may try to contact some local repairers but i doubt if they are capable enough to fix or advise on such things. You may get charged more here but is still a safe bet contacting Roland support / service centre. – Louis

KORG TR 76 Workstation Circuit Board
Question:
Hi, My KORG TR 76 workstation keyboard needs servicing / repair. I will need to replace the Mainboard/CircuitBoard for my KORG TR 76 workstation keyboard (2676 KLM). Is it possible? – Benito Villalejos (LAREDO TX, US)

Answers:
Pressurise Korg to provide mainboard / circuitboard for TR Triton and Legacy Keyboards…Korg, as most of you know, no longer makes mainboards / circuitboards and related parts for legacy keyboards like the Korg TR or Triton Le. Even I am facing the same problem. I am inviting everyone who is in the same situation to write mails to Korg, distributors, forums, blogs, etc. Korg might help us if they receive a lot of mails. The idea is to pressurise them for their poor technical support. Hopefully they will offer us an alternative solution if they realise that a lot of users are not happy with their support and may not buy Korg products again. – Anonymous

Friends, need a motherboard for my Korg TR 76 workstation keyboard. My keyboard no longer lights up and it turns out Korg no longer manufactures repair accessories. I like this brand but I don?t think it is fair on their part to stop making the accessories, we’ve seen many users concerned with this same problem. Most of us need a solution from Korg for this problem. I leave my post to see if anyone can help me. – Ivan luna

I have been on a massive hunt for a circuit board for my 88 Triton LE & having absolutely no luck. I bought the keyboard off of a guy on craigslist for really cheap because it had a broken circuit board & thought could find replacement parts to fix the keyboard. I believe it is one large circuit board. The board i need has KLM-2278 stamped on it. Im not a 100% sure but I believe it is part# 001227800. It is the PCB Circuit Board that has the LCD assembly attached to it along with a row of buttons directly underneath it. They are the F1-F8 buttons. & also the buttons for the combi, media, sequencer, program, global, compare & sampling button. & also the Realtime Control Section for the effects knobs, select button, arp on/off button & the volume slider. If anybody can help, I need a quote & would like to know the Part#s for the Circuit Board so i can get an idea what this will cost me to have repaired. Thank you. – Augustine Ismael Bernal

My fatar SL 990 needs electronic card replacement. It has many dead Keys. There are two electronic cards beneath the keys that contain the contacts. I am told that the solution to the problem is to replace the cards. Are these cards generic or must they be purchased from Fatar? If so, how can I order them? I was quoted a repair price of $250.00 from a popular instrument repair company, which seems to me excessive for a job that requires unscrewing two cards and screwing in two new ones. Thanks for any help. – Vincent

Hi, Repair man mentioned that my Roland A-37 midi keyboard controller may need a new mother-board because it doesn’t turn on. I live NY. Did anyone ever replace a motherboard on your digital piano keyboard? What did it cost? – Frank

I think my SX-KN7000 circuit board is busted, where can I order one besides panasonic ? they has not call me back yet , that means they don’t have it? please help. model 3QJBG2386A on the board – Lydia lau (San Francisco)

Hi Lydia lau, I would talk to someone who sells Yamaha or other keyboard instruments, they might be able to give you some idea. If that is not helpful, I would then approach someone who assembles computers and ask him/her for his opinion. Hope that helps. – Suresh

Korg Part No. KLM-1643 Circuit Board Replacement. I purchased a Korg Concert C-46 Series online from www.shopgoodwill.com. The listing says it “powers on”. Well, after bringing it home and setting it up, yes, it “powers on”! All the LED’s light up when selecting different voices, etc. However, no audio comes out from the speakers or through the headphone jack. After opening up the piano and thoroughly inspecting the interior (wiring, circuit boards, etc) I have noticed that the main board (KLM-1643) had “several issues”. A jumper wire was installed because a trace was burned out, an IC component was replaced and really bad solder connections. It was obvious, that the board was worked on and hasn’t made the piano “operational”…In lieu of further trying to troubleshoot the board (even with the help of a service manual), I haven’t been able to localize the problem. I’ve been online and so far haven’t been able to locate any source to purchase a replacement circuit board! I’ve gone to most major websites to even try to find “parts only” Korg electric pianos or any companies that stock certain Korg circuit boards, new or used. My obvious question is, “Does anyone out there have any working knowledge of different websites that may help me locate the circuit board I need? Any additional information would help very much! – Julio Balolong Lacey WA

Understanding PCB Design, Chips for Digital Piano, Music Keyboard
Question:
On Keypress, multiple keys sound (not a chord or layer)…Hi guys, I have a Casio wk-3000 keyboard which is giving me some trouble, I have searched for the service manual only to find a wk-3700 and a wk-1200 manual which helps understand the chips etc., the problem is thus: Every 8th key, when pressed, plays the entire octave at once, i have checked the settings, reset the keyboard to no avail. The offending keys in order from left to right are thus: 1,9,17,25,33,41,49,57,65 and 73.

The LCD shows all keys in each octave range being played. I traced the keys to the keyboard matrix generator (TC190C020AF-001)and to pin 37 (KC1), which is one of the terminals for key scan signal (as written in the SM). After the key is pressed FI0 and SI0 (the first and second contacts) close, the signal then travels through an smd filter F4 (EZASTB63ABJ)and then passes through a resistor network FM17 (MNR14E0ABJ22A) before arriving at pins 25 and 26 (respectively) of the keyboard matrix generator. I have swapped the KC1 line with its neighbor KC0 and the same problem prevails, only now on the next key (2nd, 10th, 18th etc., etc.) So i am pretty sure it’s not a diode on the keypad, which was my initial thought.

Any thoughts you may have on this problem would be graciously accepted, i am about to use a Hakko smd heating tool to settle the chips in case its a solder joint problem. Funny thing is (as i bought it used WITH the problem) i was, at one stage, able to fiddle with the keys and the sound corrected itself, playing all keys perfectly, albeit briefly. So heat gun next. I tried to enclose the wk-3700 service manual which has the same keyboard layout and Keyboard matrix generator card as the WK-3000, but it will only allow me to upload images, not pdf’s, if you know of somewhere i could get a WK-3000 service manual, that would be great! Once again, any thoughts would be greatly appreciated. – Resident kennedy (Singapore)

I have the same problem as Resident kennedy, just in a Radio Shack Keyboard-MD1800 which equals the Casio WK-3700. I have a suspicion the filter F10, F11, all other circuits have 3V on leg 8 and these have only 1.7V. I removed it, but now can not find it, I have no soldering equipment. I’ll see what I invent to make one. It only passthought of 330ohm resistors and capacitors 1pfd filter in each circuit. – Lastrago

The device only lights up the LCD-Display and the one LED at the left front. The main board has a connector for a checking device, made of a LED with resistor and a switch. Using this checking device, the LED should flash 8 times (short flashtime = IC is OK, long flashtime = defective IC). But the LED flashed only 4 times, the first two times long flashtime, the second two times short flashtime. I assumed the 4 flashes represent the S-Rams. I found a broken wire on the main board and repaired it, hoping everything would be o.k. now. But not so. Now the first flash was longtime and the three others have been short time. A little success but the piano had the same symptoms. I inspected carefully the motherboard for further broken wires, made measurements with Voltmeter an oscilloscope, but without success. I suspect the socalled gate array, that plays an important role on the mainboard has a damage. If there is anybody with a better idea, please let me hear. – Helmi (Germany)

• Related: More music keyboard/digital piano related issues, repair and solutions.