Wahl Heat-Prober 392AHP, Руководство пользователя

Страница: 29 / 38

Heat-Prober
®
Platinum-RTD Thermometers User Manual
29
392 SERIES TROUBLE SHOOTING PROCEDURE
Step Problem Action to be Performed If Correct If Incorrect
13.
Set the Wahl Calibrator to 212°F and
insert into the T/C connector. Use DVM
to measure the following voltages U3-12
should be .255 to .275V U3-13 should
be .071 to
.079V
* U3-1 should be .580 to .620V
* U3-3 should be .660 to .710V
Proceed to
next
measurement
.
If any voltage is
incorrect, check
R1-R17, R35, R36,
CR6 and CR7. Also
check wires from
connector to circuit
board.
* U3-4 should be .660 to .710V U3-14
should be .017 to .079V U3-15 should
be .580 to .620V
Proceed to
next step.
Replace U3 and
if problem is not
corrected, go to
Step 16.
14.
Check the output of U1-4 for a 0 to 6
volt square wave of approx. 10 kHz
æ2 kHz.
Replace CR1
and CR2.
Proceed to next
step.
15.
Check for a sawtooth wave at U1-
1. It should have a voltage level of
1.8 to +4.2 volts.
Replace U1. If
display still
reads
-OL-replace
U4.
Replace C67 and
recheck
U1-1. If problem is
not corrected go to
step 16.
16.
Return unit to factory for repair.
* NOTE: Does not apply to 392MX and 392M with Serial Numbers before N120