Models 2510 and 2510-AT
Troubleshooting
4-15
Display board circuits
U902 is the display microcontroller that controls the VFD (vacuum fluorescent display) and
interprets key data. The microcontroller has four peripheral I/O ports that are used for the vari-
ous control and read functions.
Display data is serially transmitted to the microcontroller from the digital board via the TXB
line to the microcontroller PD0 terminal. In a similar manner, key data is serially sent back to
the mother board through the RXB line via PD1. The 4MHz clock for the microcontroller is
generated on the digital board.
DS901 is the VFD (vacuum fluorescent display) module, which can display up to 49 charac-
ters. Each character is organized as a 5
×
7 matrix of dots or pixels and includes a long under-
bar segment to act as a cursor.
The display uses a common multiplexing scheme with each character refreshed in sequence.
U903 and U904 are the grid drivers, and U901 and U905 are the dot drivers. Note that dot
driver and grid driver data is serially transmitted from the microcontroller (PD3 and PC1).
Troubleshooting
Troubleshooting information for the various circuits is summarized below. Refer to the com-
ponent layout drawings at the end of Section 6 for component locations.
Display board checks
If the front panel display tests indicate that there is a problem on the display board, use
Table 4-1. See “Principles of operation” for display circuit theory.
Table 4-1
Display board checks
Step Item/component
Required condition
Remarks
1
2
3
4
5
6
Front panel test
J1033
U902, pin 1
U902, pin 43
U902, pin32
U902, pin 33
Verify that all segments operate.
+5V, ±5%
Goes low briefly on power up, and then goes high.
4MHz square wave.
Pulse train every 1 ms.
Brief pulse train when front panel key is pressed.
Use front panel display test.
D5V supply.
Microcontroller RESET.
Controller 4MHz clock.
Control from main processor.
Key down data sent to main
processor.
2510-902-01 (E - Mar 2010)(Service).book Page 15 Tuesday, March 16, 2010 1:04 PM
Summary of Contents for TEC SourceMeter 2510
Page 3: ...2510 902 01 E Mar 2010 Service book Page 2 Tuesday March 16 2010 1 04 PM...
Page 28: ...2 Calibration 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Page 54: ...3 RoutineMaintenance 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Page 58: ...4 Troubleshooting 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Page 76: ...5 Disassembly 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Page 82: ...6 ReplaceableParts 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Page 92: ...A Specifications 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 2 33 PM...
Page 110: ...C CalibrationProgram 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
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