Since there is no service manual available on the internet by the time of writing this blog post I thought it might be a good idea to sum up some recommendations. This writeup is about a PN 80 but applies to all pianos of the PN series (like PN 60, PN 70, PN 81, PN 90 and PN 100), since they use the same hardware, basically.
The PN 80 is a 24-note polyphonic piano designed by Kawai in the early 1990ies. In Germany it cost about 3500 DM (~ 1800 €) at the time. It features eight 16-Bit Sounds (2 Piano, 2 E-Piano, Vibes, Harpsichord, Strings, Organ) and has 88 weighted keys. It's not as heavy as comparable e-pianos of that size. It's body is built of less wood and more light metal and it features weighted keys instead of hammer action, that's why.
The sound is a bit cheap in 2018, compared to modern E-Pianos with lots of memory. Memory was expensive back then and Kawai did their best to find a good compromise. But it still sounds a lot better than the sound of cheap newer pianos like the Hemingway DP series.
"Cheap" regarding the PN 80 means from a today point of view, the sustain sample loop starts a bit early and the piano lacks an equalizer to lower the typical japanese sound brilliance. Inside there are only two speakers (loud enough, though) compared to the four and more used today.
The overall manufacturing is very well made and robust. Tidy wiring, separate metal box for the mainboard and controls. Plus not much dust inside despite of me being the first one ever opening it. That's why you can still use it after more than 20 years of intensive playing. Well played, Kawai.
Still, this PN 80 had two major problems.
- no sound at all
- ⅔ of the key weights had fallen off the keys
It powered up, though, indicated by the power diode. If your piano does not power up at all, check the adapter first (12V 2A center negative).
Opening the piano
Do NOT start opening the piano on the rear. The six screws on the backside hold hinges. Read all of this paragraph before going on.
(Optionally) start with 6 screws (bottom side) holding the front metal sheet covering the keys on the front side but DO NOT lift the sheet before having read the next sentences. Hold it safely while removing the screws and KEEP holding it. Note! There are 4 metal screws and two wood screws in the order M-W-M-M-W-M. Lift the metal sheet carefully since the power LED is attached to it on the left side. Get rid of its screw and finally put the sheet aside.
Finally you need to screw off 4 screws close to the edge on the left and right bottom. Lift up the piano top like a foldable cover. Remove the ground leads if you need to enlarge the opening angle, e.g. to reach the mainboard in the metal box inside.
In an earlier version of this blog entry I advised to definitely start with the front metal sheet. This might not be necessary, as N. Lewis pointed out in the comments. Actually, I don't remember why I needed to lift it, maybe it was to access the keys. Try one way or the other and feel free to put another comment below.
Fixing the issues
Oh so quiet
The no-sound-issue was solved quickly. After the usual cleaning plus button and fader maintenance (I use Kontakt Chemie Tuner 600 spray for potentiometer issues) there was sound on one stereo side. It turned out to be a torn volume fader. Opening and cleaning did not help due to loss of conductive material. So I got a replacement fader from synth-parts.com. The offered Korg 30 mm fader has the same size and specification.
The PN 80 has quite heavy weights (21 g) in each plastic key to imitate a real piano feeling. Kawai did glue them below the tip of a key. Unfortunately, the glue used here fails after some years of usage so you have to find a sustaining solution.
I've come up with two ideas and I used hot glue for both.
Take the weight (I warmed it before in the sun light), put some hot glue on the bottom and press it back into the designated space in the key. Do that fast since hot glue tends to cool fast when in contact with metal (thats why I warmed it in the sun). While pressing it deep into the key hold the key on the upperside (now bottom side because of upside down; to prevent breaking it) and use some tool to push the metal block down. The back of pliers e.g. will do.
- either scratch some scratches into the key hole (haha) above the block with some sharp knife and put some more hot glue into the whole on the left and right side. The scratches will hopefully make the glue stick better to the plastic.
- or take a short peace of straight spring steel, slightly longer than the diagonal width of the key hole. Press that metal piece in the whole and fix it with hot glue.
You need to do some cleaning afterwards and cut away all hot glue strings between the keys. For the piano I serviced in May 2018 I used the first of these two methods. I'll report back if this does not work in the long run.
Hi , yesterday i bought the used Kawai PN 70 from my friend it was working great at my friend place before i bought it , when i try to connect the Kawai PN 70 through power cord and try to swith on the piano the power is not passing to piano it doesn't on.
please can you help me what would be the problem why the power is not passing to the keboard?
hard to tell from here what the problem might be. What happened once you connected it and switched on? Did the LED light up for a short time? Did it smell? Did you hear something that could indicate a problem? Did something happen during the transport? Did it fall down? Did you transport it on a pretty uneven road?
It could simply be the power adapter. Check the voltage and polarity with a meter. Also check if the connection is solid. If the adapter fails, get a new one with the exact same parameters regarding voltage, +/- polarity and power in mA. The mA value may be higher but not lower.
If it's not the adapter, disconnect the piano, open it up. I do not know exactly what the PN 70 looks like from the inside, but I guess you might have to open a metal box to find the main board.
It could be a blown fuse, though I don't think there are fuses because it's adapter driven. If a fuse is blown, this might have been a problem from outside (wrong voltage) or a short on the amp board. Change the fuse(s) and see what happens. Only use the recommended type of fuse(s), it's usually written on the board or the fuse holder. If you use the wrong type severe damage can happen to components that are still working.
If the fuses are ok (if there are any) check if all wiring is still in the right place (transport vibrations?). Look if something looks burnt. Look first at the amplifier IC that usually is attached to a large heat sink. It could also be a voltage regulator, also attached to a heat sink. A lot more could have gone wrong, so one should check this with proper equipment, starting by checking the voltages inside.
If the LED still lights up and you just don't hear anything, connect the piano to a MIDI device to check if the keyboard is working. If so, check if MIDI is set to LOCAL OFF. Look in the Owner's Manual to set MIDI to LOCAL ON. Alternatively check with proper equipment (oscilloscope) if there is output from the D/A converter. To find it, check the types of ICs (look for a rather small one) and do a search "datasheet XYZ123456". Then trace the signal and see which component blocks it.
Hope this helps. Good luck!
Adapter for Kawai is special. Where other have + pole Kawai have - pole.
If you can't get an adapter with correct polarity you'll have to resolder the connector by cutting the wire and switching the poles. I know that switchable adapters are no choice in this case because there is not enough space around the jack on the piano, which is a pity.
I have a kawai PN80 and a silicon pad on one of the 12 bankpads has split and will not work. May I ask where I can get these silicon banks from please
The question is, is the pad or button physically broken or is the tactile switch below not functioning?
If the button is torn, try a repair with either acetone, superglue, silicone or hot glue depending on the material which I don't remember. I don't think you'll find a replacement for this.
If it's the switch get a replacement from an electronics dealer, they're cheap.
hi thanks a lot for your comments.
i have just got a kawai pn80. At the beginning i thought the sound didn't work. the volume control does not work. But when i put my ear (very very) close to the speakers i could hear a very very low sound. i try to connect the piano to external speaker but that didn't work. Any idea?
with best regards
hard to diagnose without measuring. Could be bad power (start measuring here), bad volume slider (weak/dry solder joints?), bad capacitors, a bad op amp, a broken path, bad amp ic, etc. It's hardly possible to tell what is wrong without hands on, I'm afraid.
Thanks a lot for ur quick answer (danke schon), i still don't know if it useful to fix it by a professionnel in France compared to it's current value.
I can't answer that, really. It maybe cheap, it may not. But if you plan to buy something else I would go for a piano with hammer action instead, maybe a used Yamaha or Roland if money is short. Kawai makes good pianos, too, maybe except for the PNxx series. Read some hints here: https://www.u-labor.de/6-reasons-why-you-should-not-buy-a-digital-piano-...
Hello from W. Canada! We have 2 adjacent white keys that are dead on our PN-80. When pressing the keys they make a distinct solid contact when depressed .... like one hard surface to another rather than the soft contact like working keys. Any ideas here? Thanx!
seems more like something is blocking from underneath. I've had cases where the blocking element was a hammer (unlikely here), a coin, a credit card, cardboard, cloth (unlikely due to sound). Open it up, find out. Good luck!
Hello again! Thank You very much for replying back to me! I did as you suggested and opened it up ... followed your instructions which were VERY VERY HELPFUL! So great full that I found you! I found multiple weights that had fallen out .... one weight was blocking the two keys that were dead! Problem resolved! Thank You so much for posting these instructions .... there is very little info out there on the PN-80. My oldest daughter learned to play on this keyboard (has an upright now) and now my younger daughter will inherit it for her new house!
I have Kawai PN80 . I don’t know what happened . When it’s on , all the led lights are on and I heard multiple sound look like demo or recording. Can you help us fix that problem.
you can always try a reset first, as described in the manual:
- Press any B-key while holding down the TOUCH and RESPONSE buttons
- Release both hands
If this doesn't work, a technician needs to do proper checking. It's not possible to help from the distance without measuring. Good luck!
I acquired a PN80 and it also did not power on. To my *great* surprise the culprit was the on/off switch. It tested ok with a multi-meter but it would not pass enough current to turn the piano on. It was easy to replace - thanks for the disassembly instructions, not sure I would have figured out how it was supposed to come apart without them.
Great work, congrats, happy playing! And thanks for sharing your experience here.
Also, you do NOT need to take off the front metal plate to open it. Just take out the four outer screws on the bottom (2 per side) and the sides / back will hinge up. This prevents the problem with holding the front and trying to disconnect the power LED cable while holding it.
Whoa, that's good to know. Will update the blog article. For some reason it seemed to be necessary for me, but I don't remember well, actually.
Hello Ulf, thanks a lot for your useful manual! Recently i also acquired PN80, which, i think, should be a great start for my son (4 y.o.). Unfortunately it was sold without the power adapter so i ordered one at amazon.de, which is 12v/2a. Now i plug it in, and nothing happens.
I read here that there might be 2 culprits - 1 is that the polarity required is different (is it true for PN80?) and therefore i need another adapter; and 2 is that the power on/off switch might be faulty. I'm not sure how should i check if it is the switch to blame indeed?
polarity is absolutely important. If it's wrong, nothing will happen. Hopefully a protection diode is installed (it is in this case, I'm quite sure), otherwise even the right polarity will not work afterwards. The power adapter should have 12 V/2A Center Negative. You will see a symbol on the adapter indicating this. If you take a multimeter and put the negative probe on the inside, the positive to the outside you should read +12V more or less.
If it's not the adapter, to check the power switch you need to disassemble the piano and do continuity checks with a multimeter for the power lines. The piano should not be plugged in.
If it's not the switch, all sorts of failures may be the culprit, power regulators, electrolytic capacitors, diodes etc. I do not have PN80 schematics so I could not even point you in a direction. Someone qualified should do measurements. Good luck!
Hi Ulf! Thanks a lot for your reply! Inspired by your response, i decided to change the polarity in a "dirty way" - just cut the cord and attached red to black and black to red :)
This worked and the piano sounds and works perfectly!
If it wasn't your site, then i don't even know how i could've solved this problem. So thanks a lot once again.
Hi Evgenii, that's very good news! Thanks for feedback and happy playing! All the best
Does anyone know how to remove the cover from a Kawai PN81? It is not the same as the PN80 as the cabinetry on the back is particle board, not metal, and definitely does not disassemble as described here.
Thanks in advance.
Add new comment/ Neuen Kommentar schreiben