I have three keys getting malfunctioned /cords not changing in left side, on split board.can this be fixed?

I'm almost sure that your pitch bender is going crazy and it feeds right hand with constant transpose of -2. You must change it with new one.

It depends exactly on the model of keyboard you have but in short look for the accompaniment button normally on the left hand side. With this pressed you can then get 1 finger chords in the left hand ( 2 fingers will give minor or 7th options ) check your handbook

EP-50's are notorious for problems with either the 4.65 voltage feed to the velocity sensitive keys or failure of the small zenner diaodes. Each key has a pair fo split circles on the circuit board under it. When you hit the key you connect each side of the circles and the harder you hit the keys the quicker the circuits close the louder the sound. Problem is if the voltage to either circle fails, due to bad solder, scratch on circuit board, failed diaode then the sound disappears. The fix is simple if you are knowledgeable on solder on circuit boards, can use a multimeter and can dissassemble and reassemble the keyboard. If you have to take it to a repair shop it is probably not worth fixing as this is not one of the better Roland products

Mine has the same problem with different keys! I don't know what to do o.O

Read your user manual about keyboard split. OFTEN the rhythms use the keys below F sharp for the chording of rhythm. When in this mode, you should restrict your melody to notes above F sharp that is to the left of middle C. If you play melody below this it will confuse the rhythm chording. You can likely change the split point of the keyboard, however, the F sharp split is the standard and I would suggest staying with it.

This would indicate a problem with the scanning matrix for the keys. I don't have my schematics handy right now, to analyze which part might be bad...

FIRST though, check the settings for the keyboard splits on the utility page that has the splits. I have had this get clobbered and caused an unwanted transposed voice to sound..

If you can find other combinations that cause the problem that would aid in pinpointing the exact cause.

This could be a bad disconnect diode or short or break on the keyboard contact board or even a cable between the upper and lower contact boards. (The keyboard contacts are actually split into two groups high and low).

Please be careful in opening the unit. There are lots of screws and some in wells in the back. There are different threads and lengths, Make sure they go back correctely. Be VERY careful of the ribbon cables and their orientation. ALSO the power switch leads are very short... I often remove the switch rather than try to take the leads off.

I can try to find my schematics but that will take a while. If you are not comfortable working on electronics, this is a problem for the shop.

First make sure a keyboard "split" option is not set.

Probably you are going to have to clean the key contacts. They are likely conductive rubber "pills" that are pressed onto a circuit board that has interleaved fingers. Clean both the black pills and the circuit board using ONLY 99% isoprophyl alcohol and Q-Tips.

OK... It wasn't clear from the original.

Sometimes the keyboard has a mode that splits for upper and lower part of the keyboard, usually splitting at the F#/G. Also CERTAIN voices will ONLY sound one note at a time. Piano setting would not have this problem of course.

When you play a single note does that sound? If it doesn't in the fingered mode, then there may be a processor problem in the unit/

If it does, there is probably a problem in the matrix that scans the keyboard electrically. If one of the keys were ELECTRICALLY stuck on, the processor within could not read whole sections of the keyboard.

To troubleshoot the problem, press exactly one key at a time... do they all work for say a piano voice while in the fingered mode.

Next press a key at the high end of the keyboard and try others. See if you can find an octave that fails to work.

The problem is likely imbedded in the electronics and could be anything from a dirty key contact to a cracked circuit board. It is NOT likely you can fix this yourself unless you are experienced in electronics.

In Casio Chord mode, the bottom keys up to the second F plays Bass Chords. The Keyboard is just putting the keys you play back into bass when you get up that high. If you read along the plastic edge above where they keys come out of the keyboard, it shows you where the Chord keys end and the Keyboard begins. If you want use of all the Octaves, slide the power switch to the first setting (normal).

I just fixed this exact problem today. It took me a while to figure out how to get to the key bed, but it's not impossible. I'll try to retrace my steps and describe them as well as I can:

- Turn the keyboard upside down on a table with the joystick hanging off the table. To make my directions easier to follow, the joystick should be on your left. When I say "front", I mean towards the keys, "back" towards the knobs.
- Have 3 cups for the different types of screws you'll find. A magnet-tipped screwdriver is *essential*, as some of the screws are hard to get to, and you don't want to lose them in there.
- Start by removing the bottom plate.
- Remove the right side panel -- there should be three bigger screws towards the front, and two smaller ones way down towards the back.
- Here's the tricky part... unplug all connectors from the center board. You might want to take some detailed pictures before you do that because there are some empty sockets on the board. It's actually easy to figure out what goes where because most connectors are of different sizes.
- Unplug the two red connectors that go to the left side of the key bed, and the one that goes to the small board on the key bed, but NOT the small white one. That's the aftertouch cable and it doesn't need to be disconnected.
- Unscrew the center board from the horizontal rail in the middle of the case. There should be 4 screws and a cable tie is connected to each one. There are 3 black screws in the back around the digital output slots (there wasn't a digital card on the Trinity I worked on.) -- unscrew those and remove the board VERY carefully not to pull any wires along the way.
- There are two silver plastic grounding slips -- one on the far left, one on the far right. I know you have to remove the left one, I'm not sure about the right one, but remove it just in case.
- Unscrew the long aluminum piece at the very front, the one that is under the keys when the keyboard is right side up.
- Unplug the small connector off the floppy drive. You can leave the ribbon cable connected. The are 4 screws (I think) that hold the floppy drive in place. Unscrew those and remove the drive.
- There should be 1 more screw holding the key bed in place, and it's right by one of the floppy drive screws. Get that one out and pull the key bed upward using the metal piece in the middle -- it may be stuck to the horizontal rail, even though it's unscrewed. Pry it up gently with a screwdriver if you have to. The key bed should come out. If it doesn't, check what might be keeping it in place. Don't ever force anything out of a keyboard.

OK, that's part one. Part two is fairly easy...

- Set the key bed on a table. Remove the long plastic strip at the top.
- To remove a black key, first you have to remove the two surrounding white keys. Grab the bottom part of the key (where you play it) and push towards the top (where there's a square hole). Pay very close attention to how the key is removed, because reinstalling it is the same way, just reversed (obviously). There's a flat spring underneath the key, don't worry if it pops out. It's pretty self-explanatory how to put it back.
- Remove the black key in the same manner. Most likely, the little tab that hooks the key onto the key bed is chipped or broken. In any case, you will need a new key -- unless, of course, it was just the spring that popped out.

Follow the instructions in reverse order to put it all back together. I typed this by memory, so I may have skipped a step or two. Taking this keyboard apart wasn't as easy as I expected, but not as hard as it looked. It just takes patience and being careful.

I hope this helps!