VC-MH835 (serv.man13). Adjustment and Replacement of Mechanical Parts - Sharp VCR Service Manual (repair manual)

vc-mh835 (serv.man13) service manual
Model
VC-MH835 (serv.man13)
Pages
19
Size
743.5 KB
Type
PDF
Document
Service Manual
Brand
Device
VCR / Adjustment and Replacement of Mechanical Parts
File
vc-mh835-sm13.pdf
Date

Read Sharp VC-MH835 (serv.man13) Service Manual online

9
VC-MH705HM/LM
VC-MH815HM/LM,MH85HM
VC-MH715HM,MH835HM
VROCPSV
CK
11.
JiGHMEC-M005
10.
JiGDRiVER-6
BM
9.
JiGDRiVERH-4
AP
4.
Torque Driver
JiGTD1200
CB
4. ADJUSTMENT, REPLACEMENT AND ASSEMBLY OF MECHANICAL UNITS
The explanation given below relates to the on-site general service (field service) but it does not relates to the adjustment
and replacement which need high-grade equipment, jigs and skill. For example, the drum assembling, replacement and
adjustment service must be performed by the person who have finished the technical courses.
4-1 MECHANISM CONFIRMATION ADJUSTMENT JIG
So as to perform completely the mechanism adjustment prepare the following special jigs. So as to maintain the initial
performance of the machine the maintenance and check are necessary. Utmost care must be taken so that the tape is
not damaged. If adjustment needs any jig, be sure to use the required jig.
JiGTG1200
CN
JiGMP0001
BY
1.
Torque Cassette Meter
JiGVHT-063
CZ
No.
Jig ltem
 Part No.
Code
Configuration
Remarks
JiGTG0090
CM
3.
Torque Gauge Head
JiGTH0006
AW
JiGRH0002
BR
JiGSG2000
BS
JiGSG0300
BF
7.
JiGADP003
BK
Tension Gauge
These Jigs are used for checking
and adjusting the reel disk height.
When fixing any part to the threaded
hole using resin with screw, use the
jig. (Specified torque 5 kg)
This cassette torque meter is used for check-
ing and adjusting the torque of take-up for
measuring tape back tension.
These Jigs are used for checking
and adjusting the torque of take-up
and supply reel disks.
Master Plane Jig and
Reel Disk Height
Adjusting Jig
Pinch pressing force
measuring jig
This Jig is used with the tension
gauge. Rotary transformer clearance
adjusting jig.
There are two gauges used for the
tension measurements, 300 g and
2.0 kg.
These tapes are especially used for
electrical fine adjustment.
Video
Audio
HiFi Audio
Track
625 Monoscope
7k
49µm
PAL Colour Bar
1k
49µm
This screwdriver is used for adjusting the
guide roller height.
For X value adjustment
This Jig is used for adjustment
of tension pole.
X value adjustment
gear driver
Tension Pole
Adjustment Driver
2.
Torque Gauge
6.
5.
8.
Alignment Tape
Guide roller height
adjustment driver
10
VC-MH705HM/LM
VC-MH815HM/LM,MH85HM
VC-MH715HM,MH835HM
4-2 MAINTENANCE CHECK ITEMS AND EXECUTION TIME
Perform the maintenance with the regular intervals as follows so as to maintain the quality of machine.
NOTE           : Part replacement.        : Cleaning        : Apply grease 
<Specified> Cleaning liquid Industrial ethyl alcohol
 * This mechanism does not need electric adjustment with variable resistor. Check parts. If any deviation is found, 
clean or replace parts.
Maintained
Parts
Remarks
500
hrs.
1000
hrs.
1500
hrs.
2000
hrs.
Possible symptom 
encountered
Guide roller ass’y
Sup guide shaft
Reverse guide
Slant pole on pole base
Full erase head
A/C head
Upper and lower drum ass’y
Capstan D.D. motor
Pinch roller
Reel belt
Tension band ass’y
Loading motor
Idler ass’y
Limiter pulley
Supply/take-up main brake levers
Colour and beating 
Small sound or sound 
distortion
Poor S/N ratio, no colour
Poor flatness of the 
envelope with alignment 
tape
No tape running, 
uneven colour
No tape running, tape 
slack
No tape running, tape 
slack, no fast forward/
rewind motion
Lateral noises Head 
occasionally blocked
Abnormal rotation or significant 
vibration requires replacement.
Clean tape contact part with the 
specified cleaning liquid.
Clean tape contact area with the 
specified cleaning liquid.
Clean rubber and rubber contact 
area with the specified cleaning 
liquid.
Screen swaying
Cassette not loaded or 
unloaded
No tape running, tape 
slack
Tape slack
Video head cleaning procedure
1. Apply one drop of cleaning liquid to the cleaning paper with the baby oiler.
2. Gently press the cleaning paper against the video head to fix your finger, and move the upper drum so that each head
is passed to and fro 5 times (do not move the cleaning paper).
3. Wipe with the dry cleaning paper.
Notes :
• Use the commercially available ethanol of Class 1 as
cleaning liquid.
• Since the video head may be damaged, do not move up
and down the cleaning paper.
• Whenever the video head is cleaned, replace the clean-
ing paper.
• Do not apply this procedure for the parts other than the
video head.
Parts Code
Description
Code
ZPAPRA56-001E
Cleaning Paper
AW
ZOiLR-02-24TE
Babe Oiler (Spoit)
AH
Gently press the cleaning paper to 
fix with your finger, and rotate the 
upper drum to clean.
Move to and fro 5 times for each head.
(Do not move the cleaning paper.)
Rotate the upper drum 
with one hand.
11
VC-MH705HM/LM
VC-MH815HM/LM,MH85HM
VC-MH715HM,MH835HM
Figure 4-1.
• Reassembly
1. Before installing the cassette housing control, short-
circuit between TP803 and TP802 provided at main
PWB, press the eject button. The master cam turns and
stop in eject position. Fit the drive lever to master cam
through main chassis, push down and slide the drive
lever towards to master cam.
*Eject position: Pinch Drive Cam positioning hole paral-
lel to center of Synchro Gear (Synchro gear marking
line). Synchro Gear positioning mark parallel to center
of master cam.
Figure 4-2.
2. Install in the reverse order of removal.
Notes
1. In the case when you use the magnet screw driver, never
approach the magnet driver to the A/C head, FE head,
and drum.
2. When installing or removing, take care so that the
cassette housing control and tool do not contact the
guide pin or drum.
3. After installing the cassette housing control once per-
form cassette loading operation.
4-4 TO RUN A TAPE WITHOUT THE CASSETTE
HOUSING CONTROL ASSEMBLY
1. Remove the full-surface panel.
2. Short-circuit between TP803 and TP802.
3. Plug in the power cord.
4. Turn off  the power switch.
(The pole bases move into U.L.position.)
5. Open the lid of a cassette tape by hand.
6. Hold the lid with two pieces of vinyl tape.
7. Set the cassette tape in the mechanism chassis.
8. Stabilize the cassette tape with a weight (500g) to
prevent floating.
4-3 REMOVING AND INSTALLING THE CAS-
SETTE HOUSING
• Removal
1. In the cassette removing mode, remove the cassette.
2. Unplug the power cord.
3. Remove in the following numerical order.
a) Remove two screws 
1
.
b) Pull and circle the drive lever and pull up the cassette
housing control.
Figure 4-3.
9. Turn on the power switch.
10. Perform running test.
Note:
The weight should not be more than 500g.
To take out the cassette tape.
1. Turn off the power switch.
2. Take out the cassette tape.
1
500g
Weight to prevent
float (500g)
Mechanism chassis
From Bottom View
Pinch Drive
Cam
Synchro
Gear
Master 
cam
From top view
Main chassis
Drive 
Lever
Phase 
matching
Master cam
Line of 
synchro 
gear.
Hole of Pinch 
drive cam.
12
VC-MH705HM/LM
VC-MH815HM/LM,MH85HM
VC-MH715HM,MH835HM
4-5 REEL DISK REPLACEMENT AND HEIGHT
CHECK
• Removal
1. Remove the cassette housing control assembly.
2. Remove the Supply/Take-up main brake ass'y.
3. Remove tension band from the tension arm ass'y.
4. Remove the reel disk.
Note:
Take care so that the tension band ass'y and main brake
ass'y are not deformed.
Notes:
1. When installing the reel disk, take due care so that the
tension band ass'y is not deformed and grease does no
adhere.
2. Do not damage the Supply main brake ass'y. Be careful
so that grease does not adhere to the brake surface.
• Reassembly (Take-up reel disk)
1. Clean the reel disk shaft and apply grease (SC-141) to
it.
2. Align the phase of the reel disk to that of the reel relay
gear and to install a new take-up reel disk onto the shaft.
3. Check the reel disk height and reassemble the take-up
main brake ass'y.
Note:
1. Take care so that the Take-up main brake ass'y is not
damaged. Take care so that grease does not adhere the
brake surface.
2. After reassembly, check the video search rewind back
tension (see 4-10), and check the brake torque (see 4-
14
).
• Height checking and adjustment
Note:
1. Set the master plane with due care so that it does not
contact the drum.
2. When putting the master plane, shift the reverse guide
a little in the loading direction. Care must be taken since
excessive shift results in damage.
Figure 4-4.
Note:
• Check that the reel disk is lower than part A but higher
than part B. If the height is not correct, readjust the reel
disk height by changing the poly-slider washer under the
reel disk.
• Reassembly (Supply reel disk)
1. Clean the reel disk shaft and apply grease (SC-141) to
it.
2. Match the phases of reel disk and reel relay gear, and set
the new reel disk.
3. After checking the reel disk height, wind the tension
band ass'y around the reel disk, and hook to tension arm
ass'y.
4. Assemble the Supply main brake ass'y.
Take-up reel disk
Supply reel disk
Ten
Tension arm ass'y
Supply main brake
Tension band 
ass'y
Take-up main brake ass'y
Supply reel disk
Take-up reel disk
Cassette lock
release shaft
Master plane
Page of 19

Download Sharp VC-MH835 (serv.man13) Service Manual (Repair Manual)

Here you can read online and download Sharp VC-MH835 (serv.man13) Service Manual in PDF. VC-MH835 (serv.man13) service manual will guide through the process and help you recover, restore, fix, disassemble and repair Sharp VC-MH835 (serv.man13) VCR. Information contained in service manuals typically includes schematics / circuit diagrams, wiring diagrams, block diagrams, printed wiring boards, exploded views, parts list, disassembly / assembly, pcb.