![Tektronix 2246 1Y Service Manual Download Page 172](http://html.mh-extra.com/html/tektronix/2246-1y/2246-1y_service-manual_1078850172.webp)
Maintenance—2246 1Y and 2246 Mod A Service
Table 6-9, (cont)
Measurement Error Troubleshooting Hints
Circuit
Problem
Symptoms
ADC, DAC SYSTEM (schematic Diagram 11)
A TRIG LVL
(U2304C-8)
See notes for “ A TRIG” (schematic Diagram 3).
Test: Select A trigger, set A Trig mode to NORM.
Check that A TRIG LVL can be set to any value from -2 .5 to +2.5
volts using the Trigger LEVEL control.
B REF TRIG LVL
(U2304B-7)
See notes for “ B TRIG” (hints for schematic Diagram 3).
Test: Select B trigger, set B Trig mode to NORM, and select B
Horizontal mode.
Check that B REF TRIG LVL can be set to any value from -2 .5 to +2.5
volts with Trigger LEVEL pot.
REF DLY
(U2305C-8)
“ RETURNED BAD SEARCH VALUE AT . . . ” for “ SELF CAL” on
time measurements.
Test: Run k-TIME-H measurement in ALT Horizontal mode; A at
1 ms/div, B at 0.1 ms/div.
Check that first delay zone can be positioned over length of
sweep with the k- control.
DELTA DELAY
(U2305B-7)
“ RETURNED BAD SEARCH VALUE AT . . . ” for “ SELF CAL” on
on time measurements.
Test: Use the preceding REF DELAY settings, and set first delay zone
to start of sweep with k- control.
Check that second delay zone can be positioned over length of sweep
with -H control.
REF CURSOR
(U2304D-14)
Gross value problems with Type 1 measurements.
Gross cursor problems with Types 2, 3, and 4 measurements.
Gross cursor problems with A TL and B TL.
Test: Run k- VOLTS-*! CURSOR Measurement Mode.
Check that k- cursor can be positioned +15 divisions around the
trace ground.
DELTA CURSOR
(U2304A-1)
Gross value problems with Type 1 measurements.
Gross cursor problems with Types 2, 3, and 4 measurements.
Gross cursor problems with A TL and B TL.
Test: Run k- VOLTS-*l CURSOR Measurement Mode.
Check that -H cursor can be positioned +15 divisions around the
trace ground level.
6-33
Summary of Contents for 2246 1Y
Page 13: ...2246A Service 7062 01 X The 2246 1Y or 2246 Mod A Portable Oscilloscope ...
Page 35: ......
Page 139: ......
Page 185: ......
Page 187: ......
Page 278: ...Figure 9 5b Detailed 2246 1Y or 2246 Mod A block diagram part 2 R E ...
Page 287: ......
Page 304: ...A D D J U N 1991 ...
Page 311: ...2246 1Y and 2246 Mod A Service WAVEFORMS FOR DIAGRAM 1 0 V r l III B f e I l i 6555 39 ...
Page 319: ......
Page 320: ......
Page 321: ...2246 1Y and 2246 Mod A Service WAVEFORMS FOR DIAGRAM 2 SET READOUT CONTROL CCW OFF 6555 40 ...
Page 323: ......
Page 324: ......
Page 326: ...A B C P E F G ...
Page 327: ......
Page 331: ......
Page 337: ......
Page 340: ......
Page 343: ...C l rti ...
Page 347: ...BEV JUNE 1991 7062 18 ...
Page 349: ...2246 1Y and 2246 Mod A Service WAVEFORMS FOR DIAGRAM 6 6555 43 I ...
Page 355: ...I BOARD LOCATION 8K 8J 8H 7H 8H 8H 7J 8D 7H 8H 8J 8J 7K 8K 10D 6L 6K 6L 6K 6G 5H I ...
Page 362: ......
Page 372: ...2246 1Y and 2246 Mod A Service WAVEFORMS FOR DIAGRAM 9 MORE ...
Page 373: ... 6555 72 6557 88 ...
Page 375: ......
Page 380: ...WAVEFORMS FOR DIAGRAM 10 ...
Page 387: ...WAVEFORMS FOR DIAGRAM 11 6555 73 6557 48 ...
Page 394: ...WAVEFORMS FOR DIAGRAM 12 2246 1Y and 2246 Mod A Service i f I S 1 f c i 4 i ...
Page 395: ...WAVEFORMS FOR DIAGRAM 12 cont 2246 1Y and 2246 Mod A Service ...
Page 397: ......
Page 398: ......
Page 400: ...REV JUNE 1991 7062 39 ...
Page 401: ......
Page 403: ......
Page 404: ......
Page 406: ...B 2246 IV AND 2246 MOD A ...
Page 407: ......
Page 408: ......
Page 414: ... _ 5 ...
Page 415: ...2246 1Y 2246 MOD A ...
Page 416: ......
Page 423: ...2246 1Y 2246 MOD A ...
Page 424: ...2246 1Y 2246 MOD A ...
Page 425: ......
Page 433: ......