BASIC TROUBLESHOOTING

Chapter 5

5.1 WHAT TO DO WHEN NOTHING APPEARS TO WORK 5-2

Kurzweil1000 Series Service Manual, Chapter 5 5-1

5.1 -What to do when nothing appears to work

If nothing at all happens when the unit is turned on:

A. Check AC power to the unit.

B. Check AC fuse located next to AC power cord receptacle on back of unit.

C. Check all cables inside the unit and make sure they are properly connected.

D. Check Power Supply DC voltages on J4. Ground on J4, pins 1,2 and 6.

+5 Volts on J4, pins 3 and 8.

+12 Volts on J4, pin 4.

-12 Volts on J4, pin 5.

After 2 seconds:

0- 0.5 Volts on J4, pin 10 (Reset In)

0- 0.5 Volts on J4, pin 9 (Power OK)

If any of these are incorrect, the Power Supply PCB, Power Switch, Line Filter/Fuse Assembly, or Transformer may be defective.

If the Display does not glow with a green color when the unit is turned on:

A. Check the two wire twisted pair cable connected to J8 on the CPU Board.

B. Check Power Supply DC voltages on J4.

Ground on J4, pins 1, 2 and 6.

+12 Volts on J4, pin 4.

-12 Volts on J4, pin 5.

C. Check the 100 V AC /400 Hz backlighting power supply on the CPU Board. This is comprised of R012-16, C016, 0001, 0002, T1, and J8.

Kurzweil1000 Series Service Manual, Chapter 5 5-2

If the Display glows with a green color but doesn't display any meaningful information:

~

(

A. Check Cable connected to J3 and the LCD display.

B. Check Power Supply DC voltages on J4.

Ground on J4, pins 1, 2 and 6.

+5 Volts on J4, pins 3 and 8.

+12 Volts on J4, pin 4.

-12 Volts on J4, pin 5.

After 2 seconds:

0 -0.5 Volts on J4, pin 10 (Reset In)

0- 0.5 Volts on J4, pin 9 (Power OK)

If any of these are incorrect, the Power Supply PCB, Power

Switch, Line Filter/Fuse Assembly, or Transformer may be

defective.

C. Check seating of 68000 microprocessor (U017) in it's

~ socket.

D. Check seating of Program EPROMs (U021, U032) in their

sockets .

E Check seating of PAL (UO08) in it's socket.

F. Check for Clock on 68000 (10 MHz square wave on U017,

pin 15).

G Check for /Reset and /Halt high on 68000 (UO17, pins 17 ,

and 18).

H. Check for /Power OK high (U045, pins 2 and 6).

I. Check for /DT Ack toggling (U017, pin 10). If this line

never goes low, the unit is hung in a non-existent memory

access. /DTack is generated by the PAL (UO08, pin 16).

J. Check for connection between RO05, pins 1 and 2.

K. If all else fails, start replacing U017, U021, U032, and

UO08.

If the unit will not enter Diagnostics, but instead displays

something like "Grand Piano":

~. A. Check Cable connected to J2 and the Front Panel. This is

most likely to be the cause.

B Check device UO01.

Kurzweil1000 Series Service Manual, Chapter 5

5-3