Problems with KURZWEIL PC2x

[eugen_syd]

Thank to all members for replies. Enzo, I tried to reset the keyboard but it is very hard to travel through menus as manual advise, with no display. Hard to select any options. Also, after starts up and flash of all keys there are no keys lit and no sound generated on output so I assume that keyboard is not functioning. I checked all voltages and they are present.
Today with the help form instrumentalparts.com my new display arrived. I can not wait to get home and give it another try. If this does not work I have to start thinking anout a new main processor board. Wonder how I am going to locate one of those??? I will keep you posted just if someone is interested in a KURZWEIL PC2x.
Regards from down under,
EUGEN

[eugen_syd]

Huh there was a big disapointment today. I tested my new arrived screen and I still have the same fault, SOLID SQUARES on the screen both rows. I understand that the screen does not initialize but I have no technoligy to work on surface mounted components. So now my only chance to progress is to try to find a MAIN BOARD or what KURZWEIL calls the engine board, P/N: N01230051. Does anyone has one of these board even used or have any ideea where I can get one functional?
Thank you for your help again,
EUGEN

[Jazz P Bass]

Back to Post #7.
Have you verified that U6 & U8 are good?
You need a scope to monitor the initialization process.
Ultimately it comes from the main microprocessor.

[Mars Amp Repair]

Well,
As mentioned above the power supplies is the best place to start on something as complex as this is. There is the regulator for 3volts which is crucial...they call one of them VR2 on page 107. also are you able to verify that the 2 crystals Y-1 & Y-2 are oscillating? Is there any data on the data lines anywhere?

on page 114, there is what looks like a header plug J301 that has many of the power supply pins on it as well as a pin called 'PowerUpReset'. I'm not sure where that reset originates, but a reset line stuck in 'reset' mode can cause the keyboard to do nothing as you are describing...there are so many reset lines in there it may be difficult to determine where they originate from.

It gets tough when trying to figure out if the unit actually has a 'hard component' issue, or as you've mentioned if it just lost it's program & won't boot because of that.

glen

[bkahuna]

Does the sound generation circuitry work when you play keys, and it's just the display that is down?

[eugen_syd]

Does the sound generation circuitry work when you play keys, and it's just the display that is down?

No, nothoing works and no sound.
In order to diagnose I made a little lab with Connector Board + CPU board and display. I think it should start with these 3 boards without the front panel and keyboard assembly. I have to get out my osciloscope and do some diagnostics. This has an external power supply with 2 voltages. I installed a brand new battery when I started and notticed the other day that went down to 2.9v so there is somewhere a short. I will follow all the suggestions.
I contacted musicparts.com which still sell those boards. They want $745.60 for the engine board and $350.00 for the conector board.
If there is anyone out there which has an used Engine Board for PC2x or connector board please let me know. Happy to buy another one. I would love to get this piano working as it has an inclredible keyboard assembly(heavy).
Thank a lot to all contributors.
Best regards from down under,
EUGEN

[oc disorder]

Eugene there's one working with orchestra rom for sale on Gum Tree in Aust for $1,400.00 Negotiable !
If I were you I wouldn't pump any more money into the one you have as you could spend that amount on old boards and it still may not work.
Kurzweil PC2X 88 note controller workstation with Orchestra ROM | Keyboards & Pianos | Gumtree Australia Marion Area - Sheidow Park

Looks like it has been looked after too judging by the condition of the manuals.

[eugen_syd]

Eugene there's one working with orchestra rom for sale on Gum Tree in Aust for $1,400.00 Negotiable !
If I were you I wouldn't pump any more money into the one you have as you could spend that amount on old boards and it still may not work.
Kurzweil PC2X 88 note controller workstation with Orchestra ROM | Keyboards & Pianos | Gumtree Australia Marion Area - Sheidow Park

Looks like it has been looked after too judging by the condition of the manuals.

I would pay on old boards $200-300 or around that not more. I will not spend $1,400.00 plus freight when I already have one! Even if you negotiate you have to spend over $1,000.00, plus where is the satisfaction to repair something?

Thank you for your thoughts!!!!

EUGEN
EUGEN

[Mars Amp Repair]

yeah,
you also have to be careful as some of the key contact strips could also be bad. I'm not certain about the PC2, but many of those key contact strips are no longer available as well as quite often the key weights start breaking. glen

[Mars Amp Repair]

this may seem simplistic & you may have already done this...have you just disconnected the display to determine if it is loading down some of the data lines? I experienced this once on an Alesis board...glen

[OffbeatElectronics.com(chris]

Thanks OC disorder: Q18 turned out to be the issue in the PC2x I was working on too, and your post saved me some time! The LCD remained blank at all times...the contrast pin was high 5.7 volts no matter where the contrast pot was turned, and the issue was able to be traced back to q18. By the way that transistor is used in a really simple circuit, I think most NPN silicone general purpose transistors could substitute for that.
Thanks!

[sky5031]

Eugen, I'm hoping you can help me out, my church has pc2x keyboard that been acting up (screen locks up after startup) hoping you still have a copy of the service manual for the pc2
that maybe YOU loan , send copy of to me so I can trouble shot this keyboard. And any ideas what might be causing this problem, or anyone else had this condition with the pc2

[eugen_syd]

Hi there,

Here is the manual. Good luck

Regards,
EUGEN

[eugen_syd]

Hi Everyone,

It has more than a year since I started this thread. Finally I got my PC2x working with help from Duane Gavin. I packed nicely my power board and engine board. I am glad I did that as he discovered that U1 was missing on the engine board. Took me more than 15min just to find it on the board and compared with previous picture and yes, was not there...Still after replacement did not come up immediatly, he reprogrammed the ROM chip. Now he also loaded v4.0 of the operating system. THANK YOU AGAIN DUANE, some people call him INSAINE DUANE I call him, INCREDIBLE DUANE.
Only took like 4 days turn around plus the time to travel to Australia. I will donate this keyboard to my small church and I make sure people mention Duane in their prays.
All the best from down under,
EUGEN

[g1]

Glad to hear you had good results, in case anyone needs, here is a link to Duane's Kurzweil repair:
Kurzweil Digital Piano Repair