General Maintenance
6- 16
WVR610A & WVR611A Waveform Rasterizers Service Manual
6.
If both DS971 and DS972 are flashing, then check pin 5 on main board
connector J390. When a front panel button is pressed, the front panel sends a
message to the main board via pin 3. The CPU on the main board responds
via pin 5 and this instructs the front panel to change which LEDs on the
front panel are illuminated. Pin 5 should have a burst of pulses with about
15 V signal swing and a basic pulse width of about 100
µ
s. If there is no
response from the CPU on pin 5 of main board connector J390, then the
RS232 transmitter is bad; replace the main board.
7.
If both the DS971 and DS972 LEDs are flashing and the signals at the main
board connector are also good but the operation of the front panel is not
correct, check the cable between the two boards. This can be done by
probing pin 5 on J670 of the front panel board. As in step 5, it should have a
burst of pulses about 15 V high and 100
µ
s long after a button press. If the
signal is bad, suspect the cable. If the signal is good, replace the front panel
board.
8.
If some buttons work, but others do not, then the front panel or the elasto-
meric key pads are bad. Disassemble the front panel assembly and use a
small piece of wire or foil to emulate the carbon pad on the switch mat. If
this registers as a switch closure then replace the elastomeric key pad.
Otherwise replace the front panel board.
9.
If some front panel button LEDs work and others do not, then the problem
must be in the front panel board. These LEDs have the anodes connected to
+5 V and the cathodes connected to a resistor driven by a logic gate. Probe
the voltage on the LED. If the LED is bad replace it, otherwise replace the
front panel board.
10.
The FAULT LED should be lit at power up for about 10 seconds. It should
also be lit if either fan is stopped. If it is not lit at power up or when a fan is
stopped, then check the voltage on the LED. The cathode connects to a
332 ohm resistor tied to ground and the anode connects to the output of a
logic gate. If the voltage looks correct, then replace the LED, otherwise
replace the front panel board.
11.
If the buttons and LEDs work but knobs do not work, then replace the front
panel.
12.
If the buttons and LEDs work but the beeper does not sound, then replace the
front panel board.
It is sometimes difficult to isolate the root cause of audio problems. Most audio
problems are due to faults on the audio board, but the audio board communicates
with the main board, so in some cases the problem may be there as well. This
test isolates an audio POST failure to either the audio board, main board, or the
cable between.
Audio POST Failure
Summary of Contents for WVR610A
Page 4: ......
Page 14: ...Table of Contents x WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 18: ...Service Safety Summary xiv WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 22: ...Preface xviii WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 23: ...Specifications...
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Page 53: ...Operating Information...
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Page 90: ...Operating Basics 2 36 WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 132: ...Changing Instrument Settings 2 78 WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 139: ...Theory of Operation...
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Page 147: ...Performance Verification...
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Page 201: ...Adjustment Procedures...
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Page 204: ...Adjustments 5 2 WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 205: ...Maintenance...
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Page 228: ...Repackaging Instructions 6 22 WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 229: ...Options...
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Page 234: ...Options and Accessories 7 4 WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 235: ...Diagrams...
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Page 243: ...Replaceable Electrical Parts...
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Page 246: ...Electrical Parts List 9 2 WVR610A WVR611A Waveform Rasterizers Service Manual...
Page 247: ...Replaceable Mechanical Parts...
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