Test Tool Software Does Not Run; Software Runs, Test Tool Not Operative - Fluke ScopeMeter 123 Service Manual

pins of N501, or N501 defective. Check the +VD supply voltage on D-ASIC D471.
Temporarily remove R470 to check for short circuit.
5. Check N501 pin 64 (VGARVAL) for +3.3V. If not correct:
a. Check if the line is shorted to ground.
b. Check N501 pin 73 (REFPWM2) for +3V3. REFPWM2 is supplied by N501,
and derived from REFP on the reference circuit on the Trigger part. Check
TP307 (N501 pin 72, REFP) for 1.22V, check V301/R307. If no 1.22V, and
V301/R307 and connections are correct, then replace N501.
c. Check N501 pin 12 (NETVALID) for +2.6V. If not correct, proceed as
indicated in Section 7.3, step 6.
d. Check the Power ON/OFF function, see Section 7.5.13.
6. Check X-tal signals on TP473 (32 kHz), and TP476 (25 MHz); if not correct check
connections, replace X-tals, replace D471. The 16 MHz clock on TP474 runs only if
the test tool software runs. If the 16 MHz clock is present, then continue at
Section7.4.3.

7.4.2 Test Tool Software Does not Run.

1. Turn the test tool OFF and ON again.
2. Check D471 pin 59 (row1) for a 100 kHz square wave.
If no 100 kHz is not present, but you heard a weak beep, the test tool software runs,
but the buzzer circuit does not function correctly. Go to Section 7.5.10 to check the
buzzer circuit, then continue at Section 7.4.3 to see why the test tool cannot be
operated.
If a 100 kHz square wave is present, the MASK software is running. Continue at
step 3.
3. Check TP486 (RP#) for >3V. If a power adapter voltage >19V is supplied, TP486 is
+12V.
If not correct then check TP487 for +3.3V (generated by D471), and check V481.
4. Load new software to see if the loaded software is corrupted. See Section 7.6.
5. Do the RAM test, see Section 7.5.12.
6. Check for bad soldered address/data lines and IC pins.
7. Replace FLASH-ROM D474 and RAM D475.

7.4.3 Software Runs, Test Tool not Operative

1. Check the Display and Backlight function, see Section 7.5.1
2. Check the Fly Back Converter, see Section 7.5.2
3. Check the Keyboard function, see Section 7.5.3
Corrective Maintenance
7.4 Starting with a Dead Test Tool
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