Troubleshooting 77
Figure 3-22. Location of Front Panel Board Holding Screw and Restraining Tab
A1 Main Board
a.
Remove the top cover and the A2 board (Isolator or GPIB board).
b.
Disconnect all cables going to connectors on the main board.
Note
Be sure to mark any or all cables prior to removal so that no mistake is made later when reinstalling
these cables.
c.
Disconnect the ground wire between the main board and the chassis. (This wire is secured to the side of the chassis near
the AC input).
d.
For 500 watt 6x5xA models only:
Disconnect the following DC power cables from connectors on the tunnel boards which are located on Heat
Sink Assembly A4:
•
Cables W12 and W14 from J202 on the top left tunnel board (A4A1) and bottom left tunnel
board (A4A2), respectively.
•
Cables W16 and W18 from J302 on the top right tunnel board (A4A3) and bottom right tunnel
board (A4A4), respectively.
e.
Remove two screws (one on each side, near J691 and J450, respectively) which secure the main board to the chassis.
f.
Slide the main board towards the front panel to release it from six chassis mounted standoffs and then lift the board out
of the chassis.
A4 Heatsink Assembly (500 Watt Models 6x5xA Only)
This assembly is comprised of a top heatsink with left (A4A1) and right (A4A3) tunnel boards, a bottom heatsink with left
(A4A2) and right (A4A4) tunnel boards, and a bracket that secures the heatsink and the cooling fan in the chassis. The top
heatsink assembly slides over and is held by tracks on the bottom heatsink assembly. The bottom heatsink assembly slides
over and is held by tracks on insulated blocks at the bottom of the chassis. To disassemble the heatsink assembly, proceed as
follows:
a.
Remove the rear panel.
b.
Remove the plastic insulator (between the rear panel and the heatsink assembly). Remember to replace this insulator
when you reassemble the heatsink.
Summary of Contents for 6541A
Page 12: ...12 Verification Figure 2 1 Basic Test Setup CV TESTS CV TESTS ...
Page 18: ...18 Verification Figure 2 3 CC RMS Noise Measurement Test Setup ...
Page 30: ......
Page 32: ...32 Troubleshooting Figure 3 1 Top View with Cover Removed for 655xA 665xA Models Sheet 1 of 2 ...
Page 33: ...Troubleshooting 33 Figure 3 1 Top View with Cover Removed for 655xA 665xA Models Sheet 2 of 2 ...
Page 37: ...Troubleshooting 37 Figure 3 2 Overall Troubleshooting Flow Diagram Sheet 1 of 4 ...
Page 38: ...38 Troubleshooting Figure 3 2 Overall Troubleshooting Flow Diagram Sheet 2 of 4 ...
Page 39: ...Troubleshooting 39 Figure 3 2 Overall Troubleshooting Flow Diagram Sheet 3 of 4 ...
Page 40: ...40 Troubleshooting Figure 3 2 Overall Troubleshooting Flow Diagram Sheet 4 of 4 ...
Page 51: ...Troubleshooting 51 Figure 3 5 No Display Troubleshooting ...
Page 52: ...52 Troubleshooting Figure 3 6 OV Will Not Fire Troubleshooting ...
Page 53: ...Troubleshooting 53 Figure 3 7 OV At Turn On Troubleshooting Sheet 1 of 2 ...
Page 54: ...54 Troubleshooting Figure 3 7 OV At Turn On Troubleshooting Sheet 2 of 2 ...
Page 55: ...Troubleshooting 55 Figure 3 8 Output Held Low Troubleshooting Sheet 1 of 2 ...
Page 56: ...56 Troubleshooting Figure 3 8 Output Held Low Troubleshooting Sheet 2 of 2 ...
Page 57: ...Troubleshooting 57 Figure 3 9 Output Held High Troubleshooting ...
Page 58: ...58 Troubleshooting Figure 3 10 DAC Circuits Troubleshooting ...
Page 60: ...60 Troubleshooting Figure 3 13 Serial Down Troubleshooting Sheet 1 of 2 ...
Page 61: ...Troubleshooting 61 Figure 3 13 Serial Down Troubleshooting Sheet 2 of 2 ...
Page 62: ...62 Troubleshooting Figure 3 14 Secondary Down Troubleshooting Sheet 1 of 2 ...
Page 63: ...Troubleshooting 63 Figure 3 14 Secondary Down Troubleshooting Sheet 2 of 2 ...
Page 64: ...64 Troubleshooting Figure 3 15 Slow Down Programming Troubleshooting ...
Page 65: ...Troubleshooting 65 Figure 3 16 Isolator Board Circuits Troubleshooting ...
Page 80: ......
Page 87: ...Principles of Operation 87 Figure 4 4 Output Power and Control Circuits ...
Page 94: ......
Page 136: ......
Page 145: ...Figure 6 1 Power Supply Interconnection Diagram for All Models ...
Page 146: ...Figure 6 2 AC Power Distribution Diagram for 655xA 665xA Models ...
Page 147: ...Figure 6 3 GPIB Board Assembly Diagram sheet 1 of 2 ...
Page 148: ...2 3 4 1 6 5 7 8 Figure 6 3 GPIB Board Schematic Diagram sheet 2 of 2 ...
Page 149: ...Figure 6 4 Front Panel Board Assembly Diagram sheet 1 of 2 ...
Page 150: ...Figure 6 4 Front Panel Board Schematic Diagram sheet 2 of 2 ...
Page 152: ...Figure 6 5 A1 Main Board Assembly Diagram for 654xA 664xA Models Only ...
Page 160: ...Figure 6 6 Left Tunnel Circuits Schematic Diagram for 654xA 664xA Models Only sheet 2 ...
Page 162: ...Figure 6 7 Right Tunnel Circuits Schematic Diagram for 654xA 664xA Models Only sheet 2 ...
Page 164: ......
Page 168: ......