Maintenance— 2445 Service
4.
Remove the two screws that noid the Attenuator being
removed to the front-panel frame.
5.
Remove the two mounting screws holding the Attenu
ator being removed to the Main board (through access holes
in the front-panel compartment).
6.
Disconnect the associated multipin connector from the
Main board (either PI 0 for Channel 1 or P11 for Channel 2).
7.
Remove the two screws holding the rear attenuator
shield and remove the shield.
8.
Unsolder the two Attenuator output leads and the
compensation capacitor lead.
9. Unplug the Attenuator by gently pulling the assembly
straight up and away from the Main board.
To reinstall a removed Attenuator assembly, perform the
reverse of the preceding steps.
A1— Main Board Removal
Removal of the Main board is accomplished by the fol
lowing steps:
1. Remove the instrument Cabinet as described in that
procedure.
2.
Remove the Top-Cover Plate as described in that
procedure.
3.
Remove the Front-Panel and Variable board assembly
as described in that procedure.
4,
Disconnect the two power-supply multipin connectors
from the power supply Regulator board (PI 21 and PI 22).
5.
Disconnect the three ribbon-cable connections from
the bottom of the Main board (P411, P511, and P512).
6.
Disconnect the vertical and horizontal deflection leads
from the crt neck pins. Access is via holes in the Main
board. Use long-nose pliers to disconnect the pins by gently
pulling straight up on the connectors. Avoid putting exces
sive side pressure on the metai-to-glass seal of ihe crt neck
pins.
7.
Dibuunnect the rear-panel BNC connector leads from
the rear of the Main Board (PI 06, PI 07, and PI 08).
8.
Disconnect the CH 2 OUT connector from near the
center of the Main board (PI 05)
9.
Disconnect the six multipin connectors for the controls
beneath the crt (P111, P112, P113, P114, P115, and P116).
10.
Disconnect the two-conductor connector for the
Scale Illumination board from between the ASTIG and the
SCALE ILLUM control connections (P I81).
11.
Unsnap the Power-switch rod from the switch hinge
at the rear of the instrument by applying counterclockwise
torque to the shaft and sliding it out of the hinge.
12.
Remove the Power-switch push-button mounting
screw from the front of the instrument (on the bottom of the
front frame) and extract the Power-switch rod.
13.
Remove the two screws holding the small bracket
under the Attenuator assemblies and remove the bracket.
14.
Remove the six screws holding the Attenuator as
semblies and the CH 3 and CH 4 input connectors to the
front frame.
15.
Remove the Main board mounting screws (eleven
screws total securing the Main board to the frame).
16.
Raise the rear of the Main board to unplug J191 and
separate the Main board from the HV board. When the plug
pins are completely disengaged and the rear of the board
clears the rear frame, slide the Main board rearward out of
the front-panel frame.
17.
Lift the Main board and Delay Line clear of the instru
ment while working the power supply cables through the
slot in the frame.
To reinstall the Main board, perform the reverse of the
preceding instructions.
A8— Scale Illumination Board Removal
Removal of the Scale-Illumination board is accomplished
by the following steps:
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Summary of Contents for 2445
Page 1: ...Tektronix 2445 OSCILLOSCOPE SERVICE INSTRUCTION MANUAL ...
Page 11: ...2445 Service 3829 01 The 2445 Oscilloscope ...
Page 44: ...Theory of Operation 2445 Service 3831 10A Figure 3 1 Block diagram ...
Page 45: ...Theory of Operation 2445 Service 3831 10B Figure 3 1 Block diagram cont 3 3 ...
Page 210: ...3829 58 Figure 9 4 2445 block diagram ...
Page 214: ......
Page 217: ......
Page 219: ...2445 382 72 ...
Page 222: ...2445 ...
Page 231: ...A 1 t C t t F t G t H t ...
Page 233: ......
Page 236: ......
Page 238: ...2445 392 1 75 ...
Page 244: ......
Page 247: ...A 1 C _____ D E F G H J 2445 3811 74 ...
Page 248: ...1 2 3 4 5 6 7 8 9 i o 2445 DISPLAY SEQUENCER TRIG GERING A4B SWEEPS ...
Page 253: ......
Page 263: ... 0 2445 J8 i S ...
Page 264: ...1 2 3 4 5 6 7 i 8 I i 9 10 2445 READOUT ...
Page 275: ......
Page 278: ......
Page 281: ......
Page 283: ... 8VJNR EG 3S 5 fROM P232 5 10 A 15VUNREG 8S F R O Mn i 2445 3 0 2 S 8 I ...
Page 286: ...2445 3823 82 ...
Page 290: ...B H le w o q 87V T S o I R v n i U1 R1873 PARTIAL A9 HIGH VOLTAGE BOARD 2445 ...
Page 299: ...2445 Service DAC REF A5 CONTROL ADJUSTMENT LOCATIONS 3 ...
Page 300: ......
Page 304: ...2 R E TU R N T O 1 ...
Page 305: ...ERROR MESSAGE DIAGNOSTICS ...
Page 306: ...ERROR MESSAGE DIAGNOSTICS ...
Page 307: ...O A A C t rnra g i tiw c t 3829 89 ...
Page 308: ...RETURN TO ...
Page 309: ...FRONT PANEL TROUBLESHOOTING ...
Page 310: ...FRONT PANEL TROUBLESHOOTING ...
Page 311: ...2445 Service 3829 90 ...
Page 316: ...R E TU R N T O v 1 y ...
Page 317: ...SWEEP TROUBLESHOOTING PROCEDURE ...
Page 323: ......
Page 324: ...2445 Service 3829 85 ...
Page 325: ......
Page 326: ... KERNEL NOP DIAGNOSTIC PROCEDURE ...
Page 327: ...10 POWER SUPPLY TROUBLESHOOTING PROCEDURE 3829 94 ...
Page 330: ......
Page 334: ...2445 Service REGULATOR TROUBLESHOOTING PROCEDURE 3829 93 ...
Page 338: ......
Page 346: ...12 2445 SERVICE ...
Page 347: ...2445 SERVICE ...
Page 348: ...2445 SERVICE ...