Problems with KURZWEIL PC2x

[miles0]

I as well had to replace Q18, the MMBT2222ALT contrast bias transistor on the connector board. The transistor was apparently damaged by a brief imbalance between the +12v and -12v supplies which fed the contrast pot/transistor circuit. The PC2X owner tried to force a broken 4 pin power supply connector into its receptacle. Shame on the engineer who spec'd such a flimsy DIN connector on an otherwise remarkably tough keyboard (excluding the Fatar lead keyweights!).

Thanks for the tip on Q18!!!

[jhatzia]

I'm experiencing this same problem with a PC2x. When I switch it on, all the LEDs on the buttons flash and the display is blank just showing blocks. When I opened it up there was poor job replacing C3 on the engine board which I fixed. And the battery is reading just fine. It sounds like I need to get the OS updated and a reprogrammed ROM chip?