Service manual

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The following paragraphs describe the setups for troubleshooting the mainframe GPIB Board, and the Control Board and
Power Board in the load modules. As a general rule, the GPIB Board is tested first, with no modules connected. Then, the
GPIB Board is installed in the mainframe and individual load modules are tested.
GPIB Board Troubleshooting Setup
To troubleshoot the GPIB Board, it must be removed from the mainframe to allow access to components. DO NOT
CONNECT THE AC MAINS LINE CORD TO THE GPIB BOARD WHILE TROUBLESHOOTING THE GPIB
BOARD.
a. Carefully lay the GPIB Board on an insulated work surface. Do not slide the board around.
b. Connect a 15-volt 0.3-amp dc power supply to J207, pins 4 and 5. See Figure 3-2a for the location of J207. The polarity
of the connections to J207 pins 4 and 5 does not matter. Use of the J207-connector assembly supplied with Service Kit
06050-60004 is recommended.
c. Make the following connections for signature analysis.
1. Connect jumper RTP201 in the SA position (SA_MODE) across pins 3 and 4 of the primary test header TP201
(see Figure 3-2b).
2. Set up and connect the signature analyzer's CLOCK, START, STOP, and GND inputs as follows:
Signature Analyzer Edge
Input Setting TP201 Connection
d. Turn on the signature analyzer and use the probe to take signatures at the applicable test points given in the signature
analysis tables.
e. Upon completion of the signature analysis tests, disconnect the signature analyzer leads and return jumper RTP201 to
its normal operating position between TP201-1 and TP201-2.
Load Module Troubleshooting Setup
To troubleshoot a load module, the Control Board and Power Board must be separated following the instructions given in
Chapter 2. The GPIB Board should be installed in the mainframe, with the ac mains line cord connected normally.
Connections between the GPIB Board and the load module under test are made using the extender cable assembly supplied
in Service Kit 06050-60004.