My Roland KR 4500 powers up to a blank screen, no button led. No key sound.Power led is lit. Amp and speakers work fine with external sound input.

Read this please

https://www.justanswer.com/electronics/9xlyw-roland-digital-piano-kr-4500-piano-turns.html

and these

https://www.google.com/search?q=Roland+kr+4500+no+sound

But you will probably need a service centre for replacing components.

I know nothing about music, and I don't play piano, but I have played with these when they first came out. I was manager of a public hall and a shop brought a load of them for demonstration. It sounds like an Effects setting and I know that is one called 'Leslie', which if I remember correctly is the effect of a speaker spinning in a speaker enclosure.

Here is your manual

http://www.synthmanuals.com/manuals/roland/kr-3500/owners_manual/kr-3500_om.pdf

Service Manual and a link to Roland, to ask them direct.
Roland KR-3500 Service Manual, Analog Alley Manualswww.analogalley.com > osccart > product_info
Product: Roland Digital Intelligent Piano, model KR-3500. Service Manual , First Edition. Contains/Contents: specifications location of controls

Support - Manual Archive - Rolandwww.roland.com > support > manual_archive
HP-3500S Owner's Manual · HP-3800 Owner's ... KR-1070 Owner's Manual · KR-117 Owner's ... KR-4500 Owner's Manual · KR-4700 Owner's Manual · KR-4700 ...


Roland USA
5100 S. Eastern Ave.
Los Angeles, CA
90040
US
Phone: 323-890-3700
Fax: 323-721-4875

seems to me this will need more than most people can do. tracking down the problem will require a lot of testing of transistors and such... but just maybe it's nothing more than a loose ground wire on the circuit that powers that side. Good luck.

This unit needs to go to the shop. I beleive you've got a blown motherboard.

A number if things can be wrong with it, from the audil preamp to the the audio amplifier. Even as simple as a bad volume control. Does the actual noise change patterns when you move the volume?

Hi, With my sound engineers hat on I would use a small PA. mixer, amp and speakers!!!!
For quality you need a full, flat frequency range system with good headroom.
I assume this is for your own listening, when using an acoustic kit?
There are one box solutions.

1. Drum amps. Like a monitor wedge with an amp, Roland do a PM-10, Various other makes are available.
2. General purpose powered wedge.
3. Keyboard Amp, these are full range and available in various sizes.
4. Bass amp with high frequency driver (tweeter), not the best but will have good bottom end.
5. Powered or active speaker, much like a powered wedge, but a different shape, needs an input volume control.

All these systems need to have large bass units, 10 inch minimum, and will be in mono. Two will give you stereo,
How loud depends primarily on the sensitivity of the speaker. But manufactures insist on selling things by power. Worth looking this up.
At a couple of feet away, 20 watts should do it, with high sensitivity speakers, more likely you find most things as above start at about 70 Watts.
Good luck, I hope I have widened you choices a bit.
All the best, Chris the Fader.

Whether you are experienced in electronics repair?
if not, try this simply way:
1: Test whether the power amplifier is still working. See figure 1.
Power OFF,adjust the EQ settings as shown in the picture.
Minimize LEVEL.Switch ON Power. Touch pin 3 at the INPUT socket by using a small screwdriver or piece of wire / cable.
Slowly raise the LEVEL,a little bit only (as the clock showed 7-8) until
sound is heard in speaker. If not heard, slowly raise again LEVEL.
If audio input signal is heard,it can simply be taken to mean
that the amplifier is working.
If LEVEL at 9 o'clock position,and the audio is not heard,
the possibility of the amplifier is damaged.
Switch OFF the power. Take it to a repair place.


2: When the Power LED is lit, but no sound,
There are many possible causes, one of which is:
I have been getting 3 times similar cases, and all are caused by
two Rectifier-Diode (either or both.) damage on the power-supply-unit.
Remove/desolder,measure, if damaged replace it with a new one.
See figure 2-3.




Hope it helps. Regards.

...............

Make sure there is not a switch that makes it output to external speakers.

ALL LED's should NOT be lit all the time. If thsy are, there is a failure in the power supply.

plug headphones into the 1/4 inch main output jacks on the top... you will only hear sound in the left side headphone for each. This would verify the preamp is working.