Roland HP 330 Advanced Digital Piano

Lodewicus - I hope you had better luck with getting a schematic than I did. I also have a HP-330, but can't get any service information on it.

If you find a source for parts, please let me know. I need a new control board for the same model (the one that has all the buttons)

I wonder if you ever resolved your problem. I'm asking because I have an HP-330 here with the exact symptom. No sound on the right speaker, nor on the right headphone channel or the right Output on the rear.

This applies to all Piano sounds. However, if I feed a signal into the Left and Right Input this will be played in Stereo on all described channels. So it is not the amp nor the pre-amp or speakers. It's not the speaker protection relay either which I suspected at first.

Lodewicus - did you find a solution?

I found out that in my case the D/A-unit fails. The mainboard gives me the left channel and suppresses the right one. Also listening carefully I hear that anti-aliasing is not working well. So I suppose it's the D/A. Unfortunately, it seems not to be possible to replace it by design. Since I'm an analogue guy this is the utmost I could do so I skipped any ambitions here.

Roland Germany wrote me that mainboards for 330/530/730 are no longer available.

So I bridged the left and right channel at the volume fader and cut the wire to the fader board on pin 3 (CN16 on amp board), since this is the dead line. So the piano plays in mono which is ok for now. The Aliasing-noise is a bit disturbing but I 'll have to turn down brilliance and live with it.

By the way, I moved the memory buffer gold cap (looks like an upright battery, look at front left) a little off the mainboard since I have had mainboards here with gold cap leakages and this has always caused serious damage.

Hi everyone,

I'm digging this thread up in hope one of you may have more information. Finding support for the HP 330 is hard. But I guess that's what you get for having non-mainstream products that are older than web itself.

My 330 has gone dead silent except for a "white-like" noise coming out of both speakers. The audio-in jacks are still working so I blame the D/A converter. It seems to me that noise could come of one faulty D/A chip leaving the audio line ungrounded.

The piano has rested unpowered since the 90's and I remember it had the same fault, although intermittent at the time.

The controls and display are still responsive so I'll try to test the MIDI output. Some VSTs might save the day ! Otherwise I am left with a PA (which will shortly become a glorified Bluetooth speaker :)

Hi everyone,
My HP330 didn't appreciate the last move: the right speaker produces a "white noise", than can be dimmed down by the volume button, even when no key is pressed.
I disconnected the speaker and now, the piano plays correctly on one speaker only.
I found on another forum that some aging chemic capacitors (16V 10mF 67) could be the root cause of this trouble.
I've them located on an FP8 Board, but am not sure where they are located on a HP-330 Board.
I suspect the two ones on the higher left corner.
Can anyone confirm that ?

Hi all, just wondering if any of you have made progress in diagnosing the No sound fault?
I have an HP-330 which started off with a hissing noise in the background and eventually led to no sound, yet the piano responds to button presses etc. I would really like to bring it back to life so any help from you folks, or pointers to other forums or sites would be very welcome.
Thank you
Nick

I found Roland service manuals here:

http://synfo.nl/pages/servicemanuals.html

For those with no sound at all but the control panel comes on and is functional, check all the voltage outputs from the transformer.