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There are currently no product reviews.
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complete and unabridged very good quality
easy to download.
recieved in two days.
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Awesome manual. Complete diagrams of all board assemblies as well as how to get to each part of the t.v. down to the individual screws and their locations. Get it.
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perfect copy, im very satisfied, i was need the diagram over the powersupply and
the copy was very sharp
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This is exactly the service manual I needed.
Complete with all schematics, partslists, PCB layouts and alignment instructions.
This manual covers both the T-4970 en T-488F Onkyo tuner.
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IF PRINTED CIRQUIT BOARD WIRING VIEW WAS ONE TONE LIGHTER, THEN 5 STAR RANK HAS TO BE MY CHOISE.
SECTION 3 ELECTRICAL BLOCK CHECKING
Note : 1. CD Block is basically designed to operate without adjustment. Therefore, check each item in order given. 2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated. 3. Use an oscilloscope with more than 10M� impedance. 4. Clean the object lens using an applicator with neutral detergent when the signal level is low than specified value with the following checks. Note : A clear RF signal waveform means that the shape � � � can be clearly distinguished at the center of the waveform. RF signal waveform
VOLT/DIV : 200mV TIME/DIV : 500ns
S Curve Check
oscilloscope BD board TP (FE) TP (VC)
level : 1.25 ± 0.25 Vp-p
E-F Balance Check
oscilloscope BD board
Procedure : 1. Connect oscilloscope to test point TP (FE) on BD board. 2. Connect between test point TP (FEI) and TP (VC) by lead wire. 3. Turn Power switch on. 4. Put disc (YEDS-18) in and turn Power switch on again and actuate the focus search. (Actuate the focus search when disc table is moving in and out.) 5. Check if the oscilloscope waveform (S-curve) is symmetrical between A and B. And confirm peak to peak level within 3±1 Vp-p. S-curve waveform
symmetry
TP (TE) TP (VC)
Procedure : 1. Connect test point TP1 (ADJ) to ground with a lead wire. 2. Connect oscilloscope to test point TP (TE) on BD board. 3. Turned Power switch on. 4. Put disc (YEDS-18) in to play the number five track. 5. Press the �3� button. (The tracking servo and the sledding servo are turned OFF.) 6. Check the level B of the oscilloscope's waveform and the A (DC voltage) of the center of the Traverse waveform. Confirm the following : A/B � 100 = less than ± 22% Traverse waveform
A within 3 ± 1 Vp-p B
Center of the waveform B
6. After check, remove the lead wire connected in step 2. 0V Note : � Try to measure several times to make sure than the ratio of A : B or B : A is more than 10 : 7. � Take sweep time as long as possible and light up the brightness to obtain best waveform. 7.
A (DC voltage)
level : 1.3 ± 0.6 Vp-p
RF Level Check
oscilloscope BD board TP (RF) TP (VC)
Press the �8� button. (The tracking servo and sledding servo are turned ON.) Confirm the C (DC voltage) is almost equal to the A (DC voltage) is step 6. Traverse waveform
Procedure : 1. 2. 3. 4. Connect oscilloscope to test point TP (RF) on BD board. Turned Power switch on. Put disc (YEDS-18) in to play the number five track. Confirm that oscilloscope waveform is clear and check if RF signal level is correct or not.
0V
C (DC voltage)
Tracking servo Sledding servo OFF
Tracking servo Sledding servo ON
8.
Disconnect the lead wire of TP (ADJ) connected in step 1.
�8�
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