Testing The Central Board - North Star DIMENSION Service Manual

TROUBLESHOOTING
Central Board
Introduction
This section of the chapter contains testing and
troubleshooting procedures for the central board.
Before using this section, verify that all power supply
voltages are present and correct.
Note: The following procedure applies only to the multi-
layer central board. Testing procedures for the double-
layer central board will be available in future releases
of this manual.
Equipment
North Star recommends use of a 100 MHz bandwidth,
Needed dual-trace oscilloscope.
Procedure :
Testing the Central Board
1. Check all power supply voltages.
2. Check the RESET* signal (TP8). It should be low at power up and
then go high and stay high .
If the signal is incorrect , go to the next
step.
3. Check the RES* input to the processor (TP9). It should be low at
power up and then go high and stay high. If the signal is incorrect,
go to the next step.
4. Check the PUC signal from the power supply (pin #3 on the power
connector). It should be low at power up and then go high and stay
high. If the signal is incorrect, the power supply is not producing a
,.•. power-up clear.
DIMENSION Service Manual 2-63