- 2 -
PN-1740B,K
To engineers in charge of repair or
inspection of our products.
Before repair or inspection, make sure to follow
the instructions so that customers and Engineers
in charge of repair or inspection can avoid suf-
fering any risk or injury.
1. Use specified parts.
The system uses parts with special safety features against
fire and voltage. Use only parts with equivalent charac-
teristics when replacing them.
The use of unspecified parts shall be regarded as re-
modeling for which we shall not be liable. The onus of
product liability (PL) shall not be our responsibility in cases
where an accident or failure is as a result of unspecified
parts being used.
2. Place the parts and wiring back in their original positions
after replacement or re-wiring.
For proper circuit construction, use of insulation tubes,
bonding,gaps to PWB, etc, is involved. The wiring con-
nection and routing to the PWB are specially planned
using clamps to keep away from heated and high voltage
parts. Ensure that they are placed back in their original
positions after repair or inspection.
If extended damage is caused due to negligence during
repair, the legal responsibility shall be with the repairing
company.
3. Check for safety after repair.
Check that the screws, parts and wires are put back se-
curely in their original position after repair. Ensure for
safety reasons there is no possibility of secondary
ploblems around the repaired spots.
ADJUSTMENTS
This unit is not include control switching block so that used the special adjustment jig for measuring.
Switch of diversity
*
How to fix the MAIN channel.
While holding the buttons of M1 and M3, turn on the power switch of the jig.
*
How to fix the SUB channel.
While holding the buttons of M4 and M6, turn on the power switch.
*
To release the MAIN or SUB channel, turn off the power switch.
If extended damage is caused due to negligence of re-
pair, the legal responsibility shall be with the repairing
company.
4. Caution in removal and making wiring connection to the
parts for the automobile.
Disconnect the battery terminal after turning the ignition
key off. If wrong wiring connections are made with the
battery connected, a short circuit and/or fire may occur.
If extensive damage is caused due to negligence of re-
pair, the legal responsibility shall be with the repairing
company.
5. Cautions regarding chips.
Do not reuse removed chips even when no abnormality
is observed in their appearance. Always replace them
with new ones. (The chip parts include resistors, capaci-
tors, diodes, transistors, etc). The negative pole of tanta-
lum capacitors is highly susceptible to heat, so use spe-
cial care when replacing them and check the operation
afterwards.
6. Cautions in handling flexible PWB
Before working with a soldering iron, make sure that the
iron tip temperature is around 270 . Take care not to
apply the iron tip repeatedly(more than three times)to the
same patterns. Also take care not to apply the tip with
force.
7. Turn the unit OFF during disassembly and parts replace-
ment. Recheck all work before you apply power to the
unit.
Item
Procedure
Measuring
instrument
FM noise
convergence
MAIN channel
1. Connect to the jig and fix the MAIN channel to make the unit the test mode.
2. Radio is set to 98.1MHz in up down of the jig.
3. Set the output to 0dBm(0.775V) by main volume.
4. Input the 98.1MHz/55dBu(1kHz, 30% MOD, 22.5kHz Div.) SSG signal.
5. Adjust the outputs to -24dB by VR103 when the SG output is set to -20dBu.
SUB channel
1. Fix the SUB channel and follow the same adjustment steps as MAIN above.
2. Adjust the outputs to -19dB by VR101 when the SG output is set to -20dBu.
SSG
Milli-volt meter
FM SD
1. Input the 98.1MHz/32dBu(1kHz, 30% MOD, 22.5kHz Div.) signal.
2. Adjust the output of TP101 to become just high level with VR102.
SSG
Oscilloscope
Dolby level
1. Insert a Dolby level test tape(400Hz, 200nWb/m).
2. Adjust VR1(R)/VR2(L) so that an output of TP1(L)/TP2(R) is 300mV +1/-1dB.
Milli volt meter
