Sylvania MK-12.5 Service manual

SERVICE MANUAL

MK12.5 Deck Mechanism Section

(U29: N224UFL/N226UFL) (Z13: N2226FT/N2246FT) (D5: N2240FL/N2260FL) (X5: N2266FT)

VIDEO CASSETTE RECORDER

COLOR TV/VCR COMBINATION

DVD PLAYER & VIDEO CASSETTE

RECORDER

COLOR TV/DVD/VCR

TABLE OF CONTENTS

Page

Standard Maintenance ........................................................................................... 2-1-1

Service Fixture and Tools....................................................................................... 2-2-1

Mechanical Alignment Procedures......................................................................... 2-3-1

Disassembly / Assembly Procedures of Deck Mechanism.....................................2-4-1

Alignment Procedures of Mechanism.....................................................................2-5-1

Deck Exploded Views............................................................................................. 2-6-1

Deck Parts List ....................................................................................................... 2-7-1

IMPORTANT SAFETY NOTICE

Proper service and repair is important to the safe, reliable operation of all Funai Equipment. The service procedures recommended by Funai and described in this service manual are effective methods of performing service operations. Some of these service special tools should be used when and as recommended.

It is important to note that this service manual contains various CAUTIONS and NOTICES which should be carefully read in order to minimize the risk of personal injury to service personnel. The possibility exists that improper service methods may damage the equipment. It also is important to understand that these CAUTIONS and NOTICES ARE NOT EXHAUSTIVE. Funai could not possibly know, evaluate and advice the service trade of all conceivable ways in which service might be done or of the possible hazardous consequences of each way. Consequently, Funai has not undertaken any such broad evaluation. Accordingly, a servicer who uses a service procedure or tool which is not recommended by Funai must first use all precautions thoroughly so that neither his safety nor the safe operation of the equipment will be jeopardized by the service method selected.

STANDARD MAINTENANCE

Service Schedule of Components

H: Hours : Check I: Change

Deck Periodic Service Schedule

Ref.No. Part Name 1,000 H 2,000 H 3,000 H 4,000 H

B8 Pulley Assembly I

B587 Tension Lever Assembly

B31

B573, B574 Reel (SP)(D2), Reel (TU)(D2)

B37

B52

B73 FE Head

B133, B134

B410

B414 M Brake (SP) Assembly II

B416

B525

Cylinder Assembly

Loading Motor Assembly

ACE Head Assembly

Capstan Motor

Cap Belt

Idler Gear, Idler Arm

Pinch Arm(A) Assembly

M Brake (TU) Assembly

LDG Belt

B569

(2 head only)

B593

(4 head,

4 head HiFi

only)

Notes:

1.Clean all parts for the tape transport (Upper Drum with Video Head / Pinch Roller / ACE Head / FE Head) using 90% lsopropyl Alcohol.

2.After cleaning the parts, do all DECK ADJUSTMENTS.

3.For the reference numbers listed above, refer to Deck Exploded Views.

Cam Holder

Cam Holder Assembly

2-1-1 U29NMEN

Cleaning

Cleaning of Video Head

Clean the head with a head cleaning stick or chamois cloth.

Procedure

1.Remove the top cabinet.

2.Put on a glove (thin type) to avoid touching the upper and lower drum with your bare hand.

3.Put a few drops of 90% Isopropyl alcohol on the head cleaning stick or on the chamois cloth and, by slightly pressing it against the head tip, turn the upper drum to the right and to the left.

Notes:

1.The video head surface is made of very hard material, but since it is very thin, avoid cleaning it vertically.

2.Wait for the cleaned part to dry thoroughly before operating the unit.

3.Do not reuse a stained head cleaning stick or a stained chamois cloth.

Cleaning of ACE Head

Clean the head with a cotton swab.

Procedure

1.Remove the top cabinet.

2.Dip the cotton swab in 90% isopropyl alcohol and clean the ACE Head. Be careful not to damage the upper drum and other tape running parts.

Notes:

1.Avoid cleaning the ACE Head vertically.

2.Wait for the cleaned part to dry thoroughly before operating the unit or damage may occur.

ACE Head

Upper Cylinder

Do Not !

Video Head

Cleaning Stick

2-1-2 U29NMEN

SERVICE FIXTURE AND TOOLS

J-1-1, J-1-2

J-3

J-5

J-2

J-4

Ref. No. Name Part No. Adjustment

J-1-1 Alignment Tape FL8A Head Adjustment of ACE Head

J-1-2 Alignment Tape FL8N

(2 Head only) FL8NW (4 Head only)

J-2 Guide Roller Adj. Screwdriver Available

Locally

J-3 Mirror Available

Locally

J-4 Azimuth Adj. Screwdriver + Available

Locally

J-5 Flat Screwdriver - Available

Locally

2-2-1 U29NFIX

Azimuth and X Value Adjustment of ACE Head / Adjustment of Envelope Waveform

Guide Roller

Tape Transportation Check

ACE Head Height

X Value

MECHANICAL ALIGNMENT PROCEDURES

Explanation of alignment for the tape to correctly run starts on the next page. Refer to the information below on this page if a tape gets stuck, for example, in the mechanism due to some electrical trouble of the unit.

Service Information

A. Method for Manual Tape Loading/Unloading

To load a cassette tape manually:

1. Disconnect the AC plug.

2. Remove the Top Case and Front Assembly.

3. Insert a cassette tape. Though the tape will not be automatically loaded, make sure that the cassette tape is all the way in at the inlet of the Cassette Holder. To confirm this, lightly push the cassette tape further in and see if the tape comes back out, by a spring motion, just as much as you have pushed in.

4. Turn the LDG Belt in the appropriate direction shown in Fig. M1 for a minute or two to complete this task.

To unload a cassette tape manually:

1. Disconnect the AC plug.

2. Remove the Top Case and Front Assembly.

3. Make sure that the Moving guide preparations are in the Eject Position.

4. Turn the LDG Belt in the appropriate direction shown in Fig. M1 until the Moving guide preparations come to the Eject Position. Stop turning when the preparations begin clicking or can not be moved further. However, the tape will be left wound around the cylinder.

5. Turn the LDG Belt in the appropriate direction continuously, and the cassette tape will be ejected. Allow a minute or two to complete this task.

B. Method to place the Cassette Holder in the tape-

loaded position without a cassette tape

1. Disconnect the AC Plug.

2. Remove the Top Case and Front Assembly.

3. Turn the LDG Belt in the appropriate direction shown in Fig. M1. Release the locking tabs shown in Fig. M1 and continue turning the LDG Belt until the Cassette Holder comes to the tape-loaded position. Allow a minute or two to complete this task.

Top View

Moving guide T preparation (Eject Position)

Moving guide S preparation (Eject Position)

Push the tape to load it.

Push the locking tab gently to unlock when loading without a cassette.

UNLOAD /EJECT

LOAD

Side View

LDG Belt

Fig. M1

Bottom View

LDG Belt (B)

UNLOAD /EJECT

Cam Gear

Fig. M2

2-3-1 U29NMA_FC

1. Tape Interchangeability Alignment

Note: To do these alignment procedures, make sure that the Tracking Control Circuit is set to the preset position every time a tape is loaded or unloaded. (Refer to page 2-3-4, procedure 1-C, step 2.)

Equipment required:

Dual Trace Oscilloscope VHS Alignment Tape

(FL8N --- 2 head model, FL8NW --- 4 head model) Guide Roller Adj. Screwdriver Flat Screwdriver (Purchase Locally)

Note: Before starting this Mechanical Alignment, do all Electrical Adjustment procedures.

Flowchart of Alignment for tape traveling

Loading (Use a blank tape.)

Adjust the height of the Guide Rollers (Supply side and take-up side). (Use a blank tape.) (Page 2-3-3)

1-A

Not good

Check to see that the tape is not creasing and that there is no slack on the supply and take-up side Guide Rollers. (Use a blank tape.)

Adjust the X Value for maximum envelope. (Page 2-3-3) (Use Alignment Tape.)

Adjust the envelope. (Page 2-3-4)

Check the envelope.

Adjust the Audio Section. (Azimuth Alignment) (Page 2-3-4)

Check the audio output.

Check the following:

1. X Value (Page 2-3-3)

2. Envelope (Page 2-3-4)

1-A

1-B

1-C

1-D

1-B, 1-C

Not good

Do the final tape-traveling test to see that the tape runs normally in play mode without creasing or slacking.

Completion

Adjust the X value and envelope.

1-A

1-B, 1-C

2-3-2 U29NMA_FC

1-A. Preliminary/Final Checking and

Alignment of Tape Path

Purpose:

To make sure that the tape path is well stabilized.

Symptom of Misalignment:

If the tape path is unstable, the tape will be damaged.

Note: Do not use an Alignment Tape for this procedure. If the unit is not correctly aligned, the tape may be damaged.

1. Playback a blank cassette tape and check to see that the tape runs without creasing at Guide Rollers [2] and [3], and at points A and B on the lead surface. (Refer to Fig. M3 and M4.)

2. If creasing is apparent, align the height of the guide rollers by turning the top of Guide Rollers [2] and [3] with a Guide Roller Adj. Screwdriver. (Refer to Fig. M3 and M5.)

3. Check to see that the tape runs without creasing at Take-up Guide Post [4] or without snaking between Guide Roller [3] and ACE Head. (Fig. M3 and M5)

4. If creasing or snaking is apparent, adjust the Tilt Adj. Screw of the ACE Head. (Fig. M6)

Azimuth Adj. Screw

ACE Head

Flat Screwdriver

Tilt Adj. Screw

Fig. M6

Guide Roller [2]

Take-up Guide Post [4]

Lead Surface of Cylinder

Guide Roller [3]

Tape

ACE Head

Fig. M3

Fig. M4

1-B. X Value Alignment

Purpose:

To obtain maximum PB FM envelope signal at the preset position of the Tracking Control Circuit, align the Horizontal Position of the ACE Head.

Symptom of Misalignment:

If the Horizontal Position of the ACE Head is not properly aligned, maximum PB FM envelope cannot be obtained at the preset position of the Tracking Control Circuit.

1. Connect the oscilloscope to TP (C-PB and CTL) on the Main CBA. Use TP (RF-SW) as a trigger.

2. Playback the Gray Scale of the Alignment Tape (FL8N --- 2 head model, FL8NW --- 4 head model) and confirm that the PB FM signal is present.

3. Set the Tracking Control Circuit to the preset position by pressing CH UP button on the remote control unit then “PLAY” button on the unit. (Refer to note on bottom of page 2-3-4.)

4. Use the Flat Screwdriver so that the PB FM signal at TP (C-PB) is maximum. (Fig. M6)

Correct

Tape

Guide Roller

Incorrect

Tape

Take-up Guide Post

Fig. M5

2-3-3 U29NMA_FC

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