Corrective Maintenance
7.5 Miscellaneous Functions
7
7-15
4. In the terminal program type capital characters X (no ENTER!). After a number of
characters the test tool mask software will respond with an acknowledge 0 (zero).
This indicates that the communication between the Terminal program and the test
tool is accomplished.
5. Type ID
and press [Enter]
The test tool will return an acknowledge 0 (zero), and the string
Universal Host Mask software; UHM V2.1
If it does not, check the Terminal program settings, the interface connection, and the
test tool Optical Port ( 7.5.5).
6. Type EX10,#H400000,#H20000
and press [Enter]
The test tool will return one of the following acknowledges:
0 the RAM is OK.
1 syntax error in the typed command
6 the RAM does not properly function.
Notice that the acknowledge overwites the first character of the message sent to the
test tool.
7.5.13 Power ON/OFF
1. Check TP528 for +3V at power on, and 0V at power off (supplied by D471).
If not correct, do the 7.4.1. tests first!
2. Check MS444 (ONKEY, D471) for +3V; when pressing the ON key the signal must
below for 100...150 ms.
7.5.14 PWM Circuit
1. Check the PWM control signals generated by D471. The signals must show 0...3V
pulses, with variable duty cycle, and a frequency of 100, 25, or 6 kHz:
a. CHARCURD, CONTR-D ≅ 100 kHz
b. SADCLEV, POS A-D, BACKBRIG, POS B-D,
TRIGLEV2D, TRIGLEV1D, HO-RNDM ≅ 25 kHz
c. OFFSETA-D, OFFSETB-D ≅ 6 kHz
2. If not correct, check:
a. TP306 (REFPWM2) for +3.3V (used for CHARCURD SADCLEV)
b. TP304 (REFPWM1) for +3.3V (used for other PWM signals).
If TP306 and TP304 are correct, D471 may be defective.
7.5.15 Randomize Circuit
1. Check TP483 for 0...+3V pulses, 25 kHz, variable duty cycle
2. Check TP482, for +3...0V pulses, variable frequency and duty cycle.
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