Preparation for Use— 2440 Service
POWER CORD
This instrument has a detachable three-wire power cord
with a three-contact plug for connection to both the power
source and protective ground. The power cord is secured
to the rear panel by a cord-set securing clamp. The
protective ground contact on the plug connects (through
the power cord protective grounding conductor) to the
accessible metal parts of the instrument. For protection
against electrical shock, insert this plug into a power-
source outlet that has a properly grounded protective-
ground contact.
Instruments are shipped with the required power cord
as ordered by the customer. Information on the available
power cords is presented in Table 2-1, and part numbers
are listed in “Options and Accessories” (Section 7). Con
tact your Tektronix representative or local Tektronix Field
Office for additional power-cord information.
INSTRUMENT COOLING
To
prevent
instrument
damage
from
overheated
components, adequate internal airflow must be maintained.
Before turning on the power, first verify that air-intake
holes on the bottom and side of the cabinet and the fan
exhaust holes are free of any obstruction to airflow. The
scope has a thermal cutout that will activate if overheating
occurs. The scope shuts down immediately with no
attempt to save waveforms or front-panel conditions if a
cutout happens. Power will be disabled to the scope until
the thermal cutout cools down, at which time the power-on
sequence is redone. The resulting loss of the last front-
panel and waveform data will cause the power-on self test
to fail and is indicated to the user by a failed CKSUM -
NVRAM test (number 6000 in the main EXTENDED DIAG
NOSTICS menu). The cause of the overheating must be
corrected before attempting prolonged operation of the
scope. Pressing the MENU OFF/EXTENDED FUNCTIONS
button restores the scope to the normal operating mode.
START-UP
This instrument automatically performs power-up tests
each time the instrument is turned on. These tests provide
the highest possible confidence level that the instrument is
fully functional. If no faults are encountered, the instrument
will enter the Scope mode in the either ACQUIRE or SAVE
Storage mode, depending on the mode in effect when it
was powered off.
If tests are failed, the scope displays the Extended
Diagnostics menu. If the failure is in the range of 1000-
5300 and the message “HARDWARE PROBLEM— SEE
SERVICE MANUAL” is displayed with the menu, see
“Diagnostics” in Section 6 for more information. If the
failure is in 1000-5300 range, but “RUN SELF CAL WHEN
W ARMED UP" is displayed, the SELF CAL procedure
should be executed from the EXTENDED FUNCTIONS
menu (wait for the NOT W ARM ED UP message to disap
pear from the SELF CAL menu). If failures persist after the
SELF CAL is run (the “HARDW ARE PROBLEM— SEE
SERVICE MANUAL” message will be displayed), see
“Diagnostics” in Section 6 for more information.
Failure of a test in the range of 7000 to 9300 may not
indicate a fatal scope fault. Several conditions can occur
that will cause a non-fatal failure of the tests. The scope
will display “RUN SELF CAL WHEN W ARM ED U P ” to
indicate a SELF CAL should be performed. If SELF CAL
does not clear the failure (“HARDW ARE PROBLEM— SEE
SERVICE MANUAL” is displayed), the scope may still be
usable for your immediate measurement purposes. For
example, if the problem area is in CH 2, CH 1 may still be
used with full confidence of making accurate measure
ments. Press the MENU OFF/EXTENDED FUNCTIONS
button to exit EXTENDED DIAGNOSTICS and enter
Scope mode.
N O T E
T he S E L F C A L p ro c e d u re is d e ta ile d in S e c tio n 5 o f
this m a n u a l.
R e fe r to S e c tio n 6 o f this m a n u a l fo r
in fo rm a tio n o n th e p o w e r-u p te s ts a n d th e p ro
c e d u re s to fo llo w in th e e v e n t o f a fa ile d p o w e r-
u p test.
A fatal fault in the operating system will cause the
scope to abort. No displays are possible, and the user is
notified of an abort situation only by the flashing of the
Trigger LED indicators (if that is possible). Cycling the
power off then back on may clear the problem, but a
failure of this magnitude usually requires the scope to be
referred to a qualified service person for checkout and
repairs. Persistent or reoccurring failures of the power-on
or self-diagnostic tests should be brought to the attention
of a qualified service person at the first opportunity. Con
sult your service department, your local Tektronix Service
Center, or nearest Tektronix representative if further assis
tance is needed.
2-3
Summary of Contents for 2440
Page 4: ......
Page 12: ......
Page 38: ......
Page 91: ...Theory of Operation 2440 Service 3 49 Figure 3 5 Simplified CCD architecture ...
Page 120: ...Theory of Operation 2440 Service Figure 3 10 DC Restorer 3 78 ...
Page 130: ...Theory of Operation 2440 Service 3 88 ...
Page 136: ...Theory of Operation 2440 Service Figure 3 15 PWM Regulator and Inverter 3 94 ...
Page 138: ...Theory of Operation 2440 Service Figure 3 16 PWM switching waveforms 3 96 ...
Page 208: ......
Page 322: ......
Page 419: ......
Page 423: ...2440 Service Figure 9 4b 2440 Block diagram part 2 6330 27 BLOCK DIAGRAM PART 2 ...
Page 427: ......
Page 428: ...2440 Service WAVEFORMS FOR DIAGRAM 1 6 2 8 5 3 2 ...
Page 429: ......
Page 432: ...2440 Service WAVEFORMS FOR DIAGRAM 2 BUS ISOLATED 6 6 0 3 4 9 ...
Page 433: ...WAVEFORMS FOR DIAGRAM 2 ...
Page 439: ......
Page 445: ......
Page 450: ...2440 Service WAVEFORMS FOR DIAGRAM 8 6603 27 ...
Page 455: ...W A V EFO R M S FOR D IAG RAM 11 WAVEFORMS FOR DIAGRAM 11 6603 29 ...
Page 458: ...WAVEFORMS FOR DIAGRAM 12 ...
Page 463: ...WAVEFORMS FOR DIAGRAM 14 ...
Page 471: ... C N i u i t e x r 4 j u J l i 1 i 6 28 5 44 WAVEFORMS FOR DIAGRAM 18 ...
Page 476: ...WAVEFORMS FOR DIAGRAM 20 ...
Page 490: ...YES ...
Page 492: ......
Page 494: ......
Page 499: ...YES ...
Page 501: ......
Page 502: ...2440 Service FIG 1 C A B IN E T ...
Page 503: ......
Page 510: ...2440 Service SISSVHO Z Old ...
Page 511: ......
Page 512: ...A12 2440 Service F IG 3 C IR C U IT BOARDS ...
Page 513: ......
Page 517: ...10 16 R E V J U L 1993 Replaceable Mechanical Parts ...
Page 518: ...2440 Service ...
Page 519: ...FIG 4 L V H V PWR SUPPLY ...
Page 520: ...FIG 5 ACCESSORIES 2440 Service ...
Page 521: ......
Page 523: ......
Page 529: ......
Page 530: ......
Page 531: ......