Sharp VL-A111UL Service Manual - Page 18

VL-A111U/AH131U VL-AH151U/AH161U 5-4-4. Adjusting the Tu guide After replacement of Tu guide preset and adjust the height. (1) Tu guide height presetting (Figure 6) Adjust the height from the upper surface of mechanism chassis to the upper surface of lower flange with the aid of jig. Lower flange Upper flange Height setting jig Master plane (JiGMP-MX7U) Figure 6 (2) Adjusting the Tu guide (Figure 7) 1 Playback the alignment tape (VR2ABOPS). 2 Check that the tape runs at the same height near the capstan shaft in case of V/S F and V/S R. 3 If the tape running position in case of V/S R is higher than the tape running position in case of V/S F, turn clockwise the Tu guide nut. If the tape running position in case of V/S R is lower than the running position in case of V/S F, turn counterclockwise the Tu guide nut. 5-4-5. Checking the V/S F and R waveforms (Figure 8) (1) Playback the alignment tape (VR2ABOPS), and set the V/S R mode. At this time ascertain that the waveform crest pitch is kept constant for more than 5 seconds. (2) Set the V/S F mode. At this time ascertain that the waveform crest pitch is kept constant for more than 5 seconds. Unless the constant pitch is obtained, execute the checks of Section 4-2, 3, and 4. Capstan shaft Nut Pinch roller Figure 7 abcd a b c d 5-4-6. Checking after adjustment (1) Envelope check 1 Playback the alignment tape (VR2ABOPS). 2 Ascertain that the envelope maximum to minimum ratio is 65% or more. (Figure 9) 3 Ascertain that the waveform does not change remarkably. (Figure 10) Figure 8 EMIN EMAX C A C (2) Rise check Figure 9 E MIN E MAX 65 (%) Figure 10 C 1/8A 1 Playback the alignment tape (VR2ABOPS). Capstan shaft 2 Once eject the cassette, and then load it again. Tu guide 3 Set the playback mode, and ascertain that the RF waveform rises horizontally within 2 seconds. At this time ascertain that there is no tape slackness near the pinch roller. Tape slackness Tu GR 4 After V/S F, R and FF/REW execute playback, and ascertain that the RF waveform rises horizontally within 2 seconds. At this time ascertain that there is no tape slackness near the pinch roller. Tension pole Figure 11 Sup tilted pole (3) Checking the tape running 1 When the tape is played back, ascertain that tape lift and tape curl of 0.3 mm or more do not occur at the lower flange of Si roller, upper flange of Sup GR, upper flange of Tu GR, and upper/lower flange of Tu guide. Si roller Sup GR Tu GR Drum 2 In case of V/S F and R ascertain that no curl is found at each flange. Drum Tu tilted pole Pinch roller Tu guide 5-4-7. Checking and adjusting the playback switching point Refer to the description of playback switching point adjustment in section of VCR circuit adjustment. Figure 12 18