SHARP VL-WD450U
Service Manual

VL-WD250U VL-WD450U

6. INSPECTION AND MAINTENANCE ITEMS AND INTERVALS
In order to keep the mechanical section always in good condition, perform the following inspection and maintenance at regular intervals. In addition, after repair, perform the following maintenance items regardless of how long the user has been using the unit.

6-1. List of inspection and maintenance items
Inspection and maintenance location Tape running section (see section 8-3) Drum section, Video head (see section 8-3) 500 Time of use (h) 1,000 1,500 2,000 3,000

Drive Performance checks Tape running system

� � � Replace.

� � � Clean.

� � � Lubricate. Remarks Note:

� � � Check.

Symptoms that indicate need for maintenance � Block-type noise � Head hole clogging � Tape damage

<Rollers> � Replace if there is anything abnormal in the rotation, or if there is run-out (that becomes large). <Other than the above> � Clean the section that contacts the tape (especially the lower drum helical section). Use the specified cleaning liquid.

Replace the drum ass'y if the video head is cleaned but the envelope still does not appear. (When the envelope is normal, refer to "11. USEFUL TIPS".)

Timing belt Pinch roller Capstan motor Swing arm S reel base, Tu reel base Center pulley shaft Intermediate pulley shaft Swing arm boss Intermediate gear A shaft, Intermediate gear B shaft Loading motor Mode switch Abnormal noise PB · VS/R winding torque PB · VS/R · loading back tension Tu reel base ratchet torque S reel base no-load torque

� The tape fails to run. � The tape becomes slack. � Block-type noise � Abnormal noise

� Replace if there is anything abnormal.

� Abnormal noise

� Lubricate with oil. [Oil] Cosmo Hydro HV22 Note: Apply oil to the shaft, then wipe lightly with a cloth. � Replace if anything is abnormal (including the noise). � Replace any part that fails to perform within the standard.

� Cannot eject. � Fails to enter a mode. � The tape fails to run. � The tape becomes slack. � Tape damage � The play-back image is abnormal. [Oil] Cosmo Hydro HV22 [Grease] Moly Coat YM-103

[Screw lock] Three Bond 1401B [Cleaning liquid] Industrial-use ethyl alcohol

6-2. Precautions
(1) When replacing any part, always replace the cut washer that was removed with a new one. (2) This mechanism does not have control adjustment. If the control cannot be set as required, clean and or replace parts. (3) On the oil a) Always use the specified oil. (Using another kind of oil can cause various kinds of trouble.) b) Always use clean oil, without any mixed-in dirt, to lubricate bearings. (Using oil with dirt mixed in can cause the bearings to wear or to stick.) c) One drop of oil is the amount shown in the Fig. 1, on the point of a pin. (4) Perform circuit repair, tape running adjustment, etc. with the cassette controller assembly attached to the mechanism. (5) When operating the mechanism separately, apply voltage to the loading motor. However, the terminal voltage must be DC3V~4V. (When the mechanism is connected to the main PWB, do not apply external voltage to the loading motor. It may cause a trouble.) (Forcing the gears to turn by hand entails danger of breakage.) If the mechanism is separated from the unit, the capstan motor may rub and be damaged if spacing under the mechanism is inadequate. (6) To install the cassette controller, push section A in the Fig. 2. Do not push anything else. (7) Do not deform any of the mechanical parts.
Oil

1.5mm diameter or less Fig. 1

A 10

Fig. 2