TOSHIBA V 726B
General Information Also Covers V 727B Matrix
Item See Model Book
6 6 6 Deck Alignment ............................................................................ Toshiba V 856 Mech. Adjustments ...................................................................... Toshiba V 856 Deck Exploded View .................................................................... Toshiba V 856
1
<Specified input and output levels, and impedance> Video input: Negative sync, standard composite video signal 1 V(p-p), 75� Video output: Same as the video input 1 V(p-p), 75� Audio input: 308 mV(rms), more than 47 k� (phono type), more than 10 k� (21 pin type) Audio output: 308 mV(rms), less than 4.7 k� (phono type), less than 1.0 k� (21 pin type) <Alignment sequence> Recorded the alignments in the sequence as shown in Fig. 2-1-2. 2-1. Servo Circuit 1. During playback press the VTR�s channel up and down buttons simultaneously to reset to tracking center. 2. Confirm that phase difference between the fall of the DFF pulse (pin 1 of BW005) and the rise of CTL pulse (pin 2 of BW005) is 12 ± 0.5 ins. 3. Further, observe the envelope (pin 4 of BW005) waveform, and confirm that the ACE head position adjustment and linearity adjustment have been made, and C-SYNC (pin 70 of IT001) is being input during playback. 4. Set the VTR to the STOP mode.
26 27
U-View Limited
Address Data 24 0A 25 03 15 0A
5. Perform the adjustment described in the item �2-1-1. Playback Phase (PG) Adjustment�. 6. Pull out the power cord plug from the AC outlet once and insert the power cord plug into the AC outlet again. 7. Perform the channel presetting as the IT004 replaced has no channel data. 2-2. Audio Circuit
Main PC Board
Recommended Safety Parts
Item
(V726B Only) 0001C 0014C 0250 0350 0400 0450 RS045 RT809 RW012 RW021 RW030 LP002 LP020 CP001 CP003 RP018 RP021 RP071 RP091 RP092 BP 001 FP001 (V727B Only) 0001C 0014C 0250 0350 0400 RS045 RT809 RW012 RW021 RW030 LP002 LP020 CP001 CP003 RP018 RP021 70061922 70012731 70052001 70051141 70051620 70041671 70040122 70041074 70040122 70041116 70011949 70012427 70042150 70051665 70041078 70041673 Owners Manual Power Cord Front Panel Bottom Plate Top Cover Res, Fusible Res, Carbon Res, Fusible Res, Carbon Res, Fusible Line Filter Power Transformer Cap, Plastic Cap Res, Fusible Res, Fusible English 70061668 70012604 70051776 70051141 70051620 70975305 70041671 70040122 70041074 70041672 70041116 70011949 70012427 70042150 70051665 70041078 70041673 70041073 70042136 70040125 70011176 70010445 Owners Manual Power Cord Front Panel Bottom Plate Top Cover Label Res, Fusible Res, Carbon Res, Fusible Res, Fusible Res, Fusible Line Filter Power Transformer Cap, Plastic Cap Res, Fusible Res, Fusible Res, Fusible Res, Fuse Inlet Fuse, 1A, 250V English
Part No.
Description
Terminal PC Board 2-1-1. Playback Phase (PG) Adjustment Fig. 2-1-2
18 � 1� 27 � 5.6 � 39 � J 0.3W J 0.3W J 0.3W J 0.3W J 0.3W
Alignment tape specifications [1] ST-C6
Test point: Pins 1 and 2 of BW005, Pin 19 of BX102 (Video out) Test equipment: Oscilloscope
5. Press the unit�s channel up/down buttons simultaneously for more than 5s. 6. Afterwards, within 2s, press the PLAY button on the remote controller. 7. The automatic adjustment will be made for about 10s, all the displays will blink. If the automatic adjustment is not carried out, confirm that the alignment tape has a safety tab or not, and redo from the step 3. 1) When adjustment has been completed: The display will blink for 10s, stop blinking and return to the normal display in the STILL mode, then it shifts to the playback display in the playback mode. 2) When adjustment fails: It goes into the STOP mode. 8. Confirm that the play indicator is displayed, and confirm that the rising and falling edge of the SW pulse is 6.5 ± 0.5H from the V-sync front edge of the video signal.
Main PC Board 2-2-1. Bias Level Adjustment Test point: Pins 1 and 2 of BS001 Test equipment: Millivoltmeter Adjusting point: PS034 1. Set the VTR to record mode. 2. Connect pin 2 to the millivoltmeter and pin 1 to ground. 3. Adjust PS034 to obtain 3.6 (300µA) ± 0.1 mV (rms). 2-3. Self Diagnosis Function 2-3-1. Outline When a tape running stops or the VTR enters the power OFF mode, etc. due to some abnormality, the abnormality is stored in the EEPROM and displayed on the display tube. 2-3-2. Storing abnormal modes � The abnormality is classed into 5 groups, and the abnormality number, system control mode, and the mechanism position at which the abnormality occurred are stored in the EEPROM. � The writing timing is just after the abnormality occurred. 2-3-3. Abnormality mode display � Press the CH UP and CH DOWN buttons on the VTR simultaneously for more than 5s. � And then within 2s, press the STILL button on the remote control. � The system control mode at which the abnormality occurred is displayed at the channel display area, �E� is displayed at the hour digit, abnormality generation number is displayed at the minute digit, and the mechanism position is displayed in the second digit position. � The abnormality mode is displayed regardless of the power on off.
TF-SMT13 100nF M 2.2nF 400V 1.5 � 2.2k � 22 � 0.47 � 47 � J 0.3W J 0.3W J 0.3W K J 0.3W
18 � 1� 27 � 1� 39 �
J 0.3W J 0.3W J 0.3W J 0.3W J 0.3W
2-1-2. When lT004 is Replaced When IT004 is replaced, the data in the VTR is required to memorize in the new one. So perform the following procedures. 1. Press the channel up/down buttons on the VTR simultaneously for more than 5s while the display blinks and the unit is in the power off mode. 2. And then within 2s, press the CANCEL button on the remote controller. 3. After displaying the address at the channel display area and the data at the minute display area, set the address to 12 using the channel up/down buttons on the remote controller. Next, set the data to d2 using the FF/REW buttons on the remote controller. The data goes up using FF button and down using REW button.
[2] ST-C7
TF-SMT13 100nF M 2.2nF 400V 1.5 � J 0.3W 2.2k � J 0.3W
MC-Service
Electrical Adjustments
<Test equipment required> Adjustment will be performed with the following test equipment. 1. Color TV (Monitor) 2. Oscilloscope, 2 CHs, 15 MHz or higher with delay system 3. Frequency counter (7 digits or higher) 4. Millivoltmeter 5. Digital voltmenter 6. Tester(20k�/V) 7. Audio generator 8. Audio attenuator 9. Alignment tapes Part code: ST-C6: 70909409, ST-C7: 70909410 10. Alignment screw driver (jig)
11. Color pattern generator 12. Video sweep generator <Color bar signal> Color bar signals of 75% recorded on the alignment tapes are shown in Fig. 2-1-1.
Fig. 2-1-1
4. Set each address and data in the table following the description above.
