6-80
The CCO has two classes of adjustments, centering and gain. In addition, several CGD parameters are
measured and stored for use in Dynamic Calibration. Centering must be performed in all four acquisi-
tion modes because of offset differences in the different paths. Gain is performed in Short-Pipeline and
FISO modes.
IF A SELF DIAG OR EXTENDED DIAG TEST FAILS, ONE CANNOT ASSUME THE HARDWARE IS
DEFECTIVE UNLESS THE SAME TEST FAILS A SELF CAL. The reason that SELF CAL must be run
to assure a hardware failure is that SELF CAL computes new values of the constants for each test
and uses them in the subsequent tests; whereas, diagnostic tests use previously stored constants for
making the tests. If those stored values are not valid for the present operating temperature of the
scope, the test may not be able to converge to a solution.
These tests, if passed, indicate that the hardware is functional.
Testing Method:
CCD/CLOCK DRIVERS A10U350 (CH 2) and A10U450 (CH 1) (schematic diagram 10):7000
CCD
The reference waveform memories will be declared EMPTY if the WFM-HEADERS do not check
correctly. If the power remains off for an extended period (more than 3 to 5 days), the short-term NV
RAM will lose the stored data, and new waveforms will have to be acquired to fill the reference
memories. If the data is lost with a short power-off, check capacitor C896 and its connect and discon-
nect circuitry.
Troubleshooting Procedure:
Waveform Data:6300
WFM-HEADERS
If the last front-panel settings have been lost, the instrument will be set up in the INIT PANEL
configuration in the SAVE/RECALL SETUP menu. If the power remains off for an extended period
(more than 3 to 5 days), the short-term NV RAM will lose the stored data. If the data is lost with a
short power-off, check capacitor C896 and its connect and disconnect circuitry.
Troubleshooting Procedure:
Front Panel Control Settings:
6200
FP-LAST
2. Test several times by cycling the power after the instrument has completed its self testing. If the
test continues to fail, check the PWRUP line to U640 pin 2, and ensure that it is reset LO when
the power line voltage drops below the minimum line voltage. If this line does not go LO soon
enough, the power-down routines will not calculate the current check sums before the power is
completely lost.
WARIIIIIG
I
If replacing the lithium battery, avoid personal injury by observing proper methods for han-
dling and disposal. Improper handling may cause fire, explosion, or severe burns. Don't
attempt to recharge and don't crush, disassemble, heat the battery above 212°F (100°C),
incinerate, or expose contents of the battery to water. Dispose of battery in accordance
with local, state, and national regulations.
Table
6-6
(cont)
Maintenance-2430 Service
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