M aintenance—2246 1Y and 2246 Mod A Service
Table 6-9, (cont)
Measurem ent Error Troubleshooting Hints
Circuit
Problem
Sym ptom s
SR 1 CLK line
(U606B-4)
Effects same as those caused by malfunctions in SR 1.
Test: Check that the A Sweep rate changes when SEC/DIV knob
is rotated in the A Horizontal Display Mode.
SR 1 CLK TTL line
(U501-13)
Effects same as those caused by malfunctions in auxiliary section of
SR 1 (U1103, Diagram 3).
Test: HF noise in trace reduces when SCOPE BW button is lit and
increases when not lit.
Processor-to-D isplay-
Sequencer Interface
(U600)
Gross effects on all voltage and time measurements.
Test: Run DIAGNOSE and note results of SLIC CONTROL REG
test; Set the A Trigger Mode to NORM; check that the ATS 0-2
signal lines (pins 31-33) change when the A Trigger SOURCE is
changed. Check that no “ LOW REP RATE” warning occurs with
Type 4 measurements.
TDO Level Shifter
(U603, Q603, Q602)
Same as Processor-to-Display-Sequencer Interface problem.
Test: Using NORM mode for both triggers, VERT source for both
triggers, and CH 1 only displayed; apply a four-division, square-
wave signal to the CH 1 input.
In the A Horizontal mode, check that the Trig’ d LED light goes
off and the sweep stops running with the Trigger LEVEL control
at full CW rotation.
Change to AUTO mode for A trigger; check that sweep free runs
with the Trigger LEVEL control at full CW rotation.
Check that the Trig'd LED can be lit and the sweep can be trig
gered when the Trigger Level is set to within the signal limits.
Keep the A Sweep triggered for the next check.
In B Horizontal mode, check that the Trig’d LED goes off, and
the sweep stops running with the Trigger LEVEL control set at full
CW rotation.
Check that the Trig’ d LED can be lit and the sweep made to trig
ger when Trigger Level is set to within the signal limits.
Change to RUNS AFTER Mode for the B Trigger. Check that the
B Sweep free runs.
6-30
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: ......