- How to measure FET?
-
How to test the transistor with 3-terminal
measurement?
-
What are the conditions that the capacitors,
resistors, inductors and diodes unable to be
measured?
-
Can JET-300 be extended to dual press down
unit?
-
How to judge if the TestJet sensor has been
properly installed?
-
What could be the problems if it is unable
to execute the auto test when the head of the
press down unit has been lowered?
-
How to measure the small resistance?
-
Does JET-300 provide functional test?
-
How to measure the two paralleled diode?
-
How to judge the fail relay board when the
error message appear during debugging relay
board?
-
How to check the polarity of electrolyzed
capacitors?
-
How to measure the β value of the
transistor?
- How to measure the regulator IC?
1.
How to measure FET?
There are JFET, Depletion MOSFET and Enhancement
MOSFET.
a. Enhancement MOSFET
Following is an example program:

Control the voltage of gate from 2V to 3V
till it turns on completely then measuring the
Vds.
b. JFET and Depletion
MOSFET
Following is an example program:

Control the voltage of ACTVAL (Vgs) from 2V
to 3V till the FET pinches off.
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2.
How to test the
transistor with 3-terminal measurement?
| Only measure the two ends of the
diode of BC and BE for the transistor of
Japanese’ transistor (ex : 2SAxxxx) to
know if the diode is false soldering or
wrong insertion.( ex: program step 1and
2). But for US transistor (ex : 2Nxxxx
), measure the transistor with three
terminals (program step 3) to detect the
wrong insertion is necessary due to the
pin of base is in the middle. Following
is an example program: |

Control the base voltage to saturate the
transistor.
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- When R1>10R2, R1 cannot be
measured.
- When XL >10R2, L cannot be
measured; XL=2πfL
- When R2>10XL, R2 cannot be
measured.
- When the capacitor is with a
relatively large capacity, prolong
the delay time or make it in CV mode
to measure the resistance. When
10R2<XC, C cannot be measured.
- When R2>10Ω, the misoriented
inserted D is detectable.
- When L2>10L1, L2 cannot be
measured.
- When 10XL<XC, C cannot be
measured; when 10XC<X L, L cannot be
measured.
- When RL<10Ω, D cannot be
measured.
- When C2>10C1, C1 cannot be
measured. CAUTION! This feature is
opposite to those of R and L.
- When C2 is large, to measure D1
need long time. When D1and D2 are
paralleled at the same direction,
apply CM mode to measure them.
|
4.
Can JET-300 be
extended to dual press down unit?
| Yes, Just rename jet300n.exe as
jet300d.exe and take off the jumper of
the retest on the mother board. The ICT
will become a dual press down unit. |
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5.
How to judge if the TestJet sensor has been properly installed?
| When measuring the voltage (Vdc)
between two terminal probes of the
TestJet sensor and getting the values as
listed, the sensor might be in the bad
condition. Below are the reasons. |
a. If Vdc=0V,
i. the probe number setting is wrong in test
program.
ii. the cable of MUX board is bad.
iii. the cable is not well connected.
b. If Vdc=5V, the sensor plate might be open.
c. If Vdc=0.7V, the system board or MUX board
go wrong.
d. If Vdc=4.5V, the mechanical function is
fine.
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a. Check if the Fix Auto flag in the status
table is set “ON”
b. Check if the Proximity Reed Switch on the
air cylinder is properly adjusted.
c. Check if the system control board, the cable
and the fixture control board failed or not.
d. Check if the fixture control cable is
properly plugged.
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7.
How to measure the
small resistance?
| For small resistance measurement
(0.1Ω~2Ω), regard it as jumper
measurement. It is only for measuring if
any missing components occur on the
board. For more accurate measurement,
four-wire-mode measurement is
necessarily to be applied. The theory is
as below: |
| Signal sources and measurement has
different loop individually so that the
voltage on RX could be correctly
measured. Each relay board was set as
two-wire-mode, thus you need below steps
to modify to four-wire-mode:
|

a. Take out the jumpers marked JA, JB and JC
and make them open.
b. The short jumper is as
for JA0, JA1, JA2, JA3, JB0, JB1, JB2, JB3,
JG0, JG1, JG2 and JG3.
Make them open and short as
c. There are only 32 points left on relay
board, because the second connector has been
functioned as sense . To measure RX, set A as
1, B as 2 and pin 33 will set as sense
of pin 1 and pin34 as sense of pin 2
automatically.
d. The program should be set as below:

e. The modification is completed.
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8.
Does JET-300
provide functional test?
Yes, JET-300 does offer functional test.
So far, we provide +5V, -5V, +12V, +3.3V
power.

Add one more board with a 7-pin molex socket
on the back of the fixture and set the program
as below:
Image>>
Press [Alt] + [k] simultaneously in the edit
screen to show the relay code. Fill No.4 and e
with 1 and turn
on the relay to send out the proper voltage. Be
sure to turn off the power after measuring. ( as
step. 3 )
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9.
How to measure the
two paralleled diode?

Use CM mode to measure the paralleled diode.
Following is the example program:

Programming for Step 2 is to apply ACTVAL
voltage (0.6v) to make the current about 40mA.
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10.
How to judge the
fail relay board when the error message appear
during debugging
relay board?
Example:
Open on B130 (B3: P2)
The message indicates that it is open on
the P2 relay of the 3rd board belongs to the
No.130
point of the B switch. Replace the P2 relay
of B switch of the 3rd board so that the job
is done.
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11.
How to check the
polarity of electrolyzed capacitors?
(a) Leakage current
measurement
If C1 were 100uF 25V, rewrite the program as
STEP2, press F9 to measure the normal leakage
current of the capacitor and fill the value in
the STDVAL field. If C1 were misoriented
inserted,
the current value will be amplified.

Remark : Each capacitor bears different
durability, so the voltage under ACTVAL is not
fixed.
(b) Three-terminal
measurement:
This method is used to measure the electrolyzed
capacitor. Plant a probe on the top of the
capacitor (as drawing shown) and rewrite the
program as below:


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12.
How to measure the
β value of the transistor?

NPN Transistor:
Set N in MD, 1 in RG and tune the Vb voltage in
ACTVAL (start from 0.7V) until the utmost
and stable βvalue is measured and fill the
measured value in STDVAL. (ref. to STEP 1)
PNP Transistor:
Set P in MD, 1 in RG and tune the Vb voltage in
ACTVAL (start from 4.3V and downward), until
the utmost and stableβvalue is measured and fill
the measured value in STDVAL (ref. to STEP 2)

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13.
How to measure the
regulator IC?
Add external power and modify the hardware as
following steps and attached drawing A.
a. The existing fixture should be added with a
Molex 7 pin socket which will be connected
to JP9 of JET IC SCAN BOARD for power supply.
b. Pin 1 for +5V, Pin 2 for GND, Pin5 for -5V,
Pin6 for +12V and Pin7 for +3.3V. Please refer
to the attached drawing B and program below to
test its regulator IC output voltage VCC2
VTT)If the STEP 8, 10 and 12 cannot release
the voltage lower than 0.1V, increase the TM
value to the STEP 7, 9 and 11 till the STD
value of STEP 8, 10 and 12 lower than 0.1V.



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