This si likely a problem in the power supply. The regulator is probably failing and dropping the voltage to the processor below what it will operate.
The probkem PROBABLY can be isolated with freeze mist circuit cooler.
First step is to check the voltage of the 5 volt source after it fails.
If you are not adept at electronics this is not a DIY thing.
Testimonial: "So nice to talk to someone intelligent! Really appreciate the expert advice!"
That is a TYPICAL service agent that has LITTLE experience in troubleshooting down to the component level. They are a useless service agency.
FIND a person willing to do what I suggested with the circuit cooler to isolate the bad component.
Note that the bad component causing the problem could be VERY inexpensive. Most parts in the power supply which is probably where the problem is cost less than $5. It is unlikely the current service group can be talked into doing a decent job of troubleshooting this... they are either incapable or LAZY..
That is the spirit! Most music stores are really NOT into repair and farm it out to techs... some of them are "hacks" and some are board swappers. I am an electrical engineer and repair my own stuff. I get many items from stores that are "beyond repair" and fix them. MOST problems are in just a few components or a single one that is bad.
If your dad has electronics experience he can probably do a better job. Here is the cautions:
Be careful to have adequate working area when you open the unit.
Be careful to NOT damage cables... many are flat.
Have a second pair of hands available to handle the shells when you open the unit so as to not damage cables.
You will find that the main board for the MOST part is not repairable due to surface mounted parts with very fine leads. These take specialized tools to remove and replace large chips on the board.
You will find the power supply and possibly the audio amp near where the line cord comes in. With unit open and after it fails, try cooling parts within the power supply... a LITTLE squirt on a compnent, wait 5 seconds for cold to sink in, then go to the next.
You can also do this on the main board and if there happens to be a small component that is the culprit you can probably have it repaired.
Sometimes the techs actually cause damage, so make sure it works like it did before you took it to the music store...
Your minimum test equipment necessary is a little multimeter... one from Harbor Freight Tools is adequate. Beyond that one needs an oscilloscope...
PLEASE NOTE: If the power cord ties directely to the keyboard USE AN ISOLATION transformer to power the unit for safety if you probe the circuits with meters, etc.. Your dad will know this if he is into electronics at all.
Re-reading your first post I SUSPECT the problem might be with the filter capacitors in the power supply... You see, so much of the main board has to work to bring up the display initially... either something is heating up or the filter caps are not storing enough energy... The time delay of 30 seconds means there MAY be something heating that takes 30 seconds... Also check the regulator chips... there are likely some in the 7805,7815,7915 type chips that have thermal cutouts which could cause the delay in failing should they taake that time to overheat.
I have downloaded a schematic for a Roland KR117 piano which MIGHT have some stuff in common with yours... When you dad gets into the unit, he can email me directely fredy2 @ aol.com if he thinks I can help. I am in Renton WA USA
Hello,
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Thank you for your reply. I have taken it to a repair shop for an estimate --- they are telling me they think it will need a new circuit board --- over $1,000 worth --- they have done nothing so far but just turn it off and on for four days to see "if it works and for how long...".........
I definitely will do and appreciate your comments so much. I don't know much, but I know more about it from researching the internet than they seem to! They asked me to give them one more day to find the problem. Of course I will not agree to a new circuit board. This is at the music store where I bought it and they probably would like me to buy another one! I do love my old Roland though! Thanks sooooo much! My father might be able to help me - he does do some electronic work - now that we know where to start. Thanks again!
Perfect! Even I can understand this! I also know you have to be very careful with electronics, but certainly don't the specifics - until now! My dad should know exactly what you are talking about -- he has many years of experience (but not sure if he has ever worked on a piano!) I didn't want to ask him to do it, but to save that much money? Believe I will...:) Can't wait to get my keyboard back.....I think it will be worth a try!
My sincere thanks and appreciation for your time and opinions. This is way more than I could have hoped to find out. Thank you for your generous offer to help further.
Hello,
I have exactly the same problem. I have open the piano and I sugges it is a power supply problem ? Have you a schematic of the power supply available ?
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