Consider the typical failure mechanisms and their causes.
1. Cassette is not loaded or unloaded:
- broken cassette holder (VXA4661)
- "Propylene" teeth on the gear lever boot tape (VXP1339);
- faulty or improperly installed switch mechanism.
2. Tape is not threaded through:
- faulty braking mechanism podkassetnyh nodes;
- broken teeth on the drive gear lever filling tapes;
- program is broken strap.
3. Does not reach the stop lever filling the tape:
- dirty guide slot chassis or dry lubrication;
- defective mechanism freezes podkassetnyh nodes.
4. Press down tape:
- is defective or not configured the ribbon (often Unstick felt strip);
- dirty or warped pressure roller;
- bent arm position P5.
5. Tape is not moving in the playback mode:
- improperly installed or defective drive bracket with the pinch roller;
- defective central clutch that transmits rotation podkassetnye nodes. 6. Tape is not at podmatyvaetsya raspravke:
- faulty braking mechanism podkassetnogo receiving node (VXZ0313).
7. Crashes when you change modes:
- faulty switch mechanism;
- crack in program bar (in this case usually fails the phasing mechanism.)
8. Shutter does not open when unloading the cassette tape:
- broken arm opening blinds (VXL2250);
- broken shutter (VKF2709).
9. Cover will not open the cassette upon startup:
- broken arm (VML2680), mounted on the cassette holder;
- broken opener magazine covers (VDM2101).
It should be noted that the reason of incorrect work may be the
mechanism of its contamination or ingestion of foreign objects. In the
latter case, may damage the gears, the program bars and levers.ADJUSTMENT MECHANISM
The need for mechanical adjustments tape mechanism occurs after
prolonged use, the replacement of any of its parts, as well as due to
unauthorized repairs.ADJUSTING THE ARM the ribbon
[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]
1. Remove the top panel with the cassette and cassette holder.
2. Rotate the engine load to bring the mechanism to the position filled by the tape.
3. With the holes in the eccentric holder belt controller belt
tension adjusting the position of the lever. The left edge of the lever
must match the left edge of the clip (see Figure 9)..
Fig. 9 band brake lever positionADJUSTING THE TENSION BAND
PROVISIONAL ADJUSTMENT POSTS P2 and P3[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]
1. Enables playback (mounted on top of the tape length 180 minutes) and give the tape to stabilize (approximately 10 ... 20).
2. Measure belt tension in the area between the head full erase and
fasting P2 (see Fig. 10) with a meter (VFK 0132). Meter reading should
be between 22.5 ... 27.5, the
3. If the belt tension does not fit into these limits, adjust it,
moving the governor spring tension belts on short-or long tooth (in the
original position it is on the average).
Fig. 10 Location of posts
1. Remove the top panel with the cassette and cassette holder.
2. Weaken the fixing screws positions P2 and P3.
3. Rotating positions P2 and P3 in a clockwise direction, set them in the lowest position.
4. Pivoted to positions P2 and P3 2 turns counterclockwise.
5. Set the cassette holder and the top panel cassette.
6. Load the tape and start playback. Verify the absence of knee tape
in the upper and lower floors of the restrictive positions P1, P2, P3,
7. In the case of bending strip remove him adjusting positions P2 and P3.
8. Setting compatibility BM (substitutability tapes).
To configure the compatibility of the VM should do the following:
1. Adjustment positions P2 and P3;
2. Preliminary adjustment of the block of magnetic heads (BMG) in height;
3. Height adjustment BMG;
4. Precise control of BMG;
5. Adjusting the BMG horizontally. Before you begin, you should
disable the auto-tracking. To this end, the microcontroller is converted
into service mode jumper between control points:
- TP SERV and TP GND for a series of SD;
- TP 6010 and TP 6011 series HD.
Voltage at NORM / SERV / TEST MCU in this case is 2,5 ... 4 B. At the end of the jumper settings are removed.
In the models later release disable Auto-tracking can be done
installing the service mode by pressing two buttons, the FF and EJECT.ADJUSTMENT POSTS P2 and P3
To adjust the tracking set to the middle position while pressing the
TRACKING "+" and "-" button on the remote control (RC) when playing a
standard recording (cassette VFJ8125H3F).
Oscilloscope control signal to the amplifier output signal from the
video heads (RF SIGNAL). To obtain a stable image scan of the
oscilloscope can zasinhronizirovat pulse switch the video heads (HEAD SW
PULSE).[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]
Fig.11 The shape of the envelope RF-signal (start reading)[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]
Fig.12 The shape of the envelope RF-signal (end of reading)
If the envelope of the RF-signal at the input tape in contact with
the video heads (when you turn on the video heads) has the form shown in
Fig. 11A or 11B, it is necessary to adjust the position P2 to obtain
the waveform shown in Fig. 11C. If the envelope of the RF-signal at the
output tape from contact with the video heads (when you turn off the
video heads) has the form shown in Fig. 12D or 12E, you should adjust
the position P3 for the waveform shown in Fig. 12F. Adjusting the
tracking in either direction from the central position, you must make
sure that the shape of the envelope corresponds to that shown in Fig.
13.V if necessary, further adjust positions P2 and P3.[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]
Fig.13 The shape of the envelope RF-signal at different positions of adjustment trackingPre-installation of unit magnetic heads (BMG)
Rotate the screw A (see Fig. 14) to touch his gear and then turn it to 1.5 turns counter clockwise.[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]
Fig.14 Block stationary heads
Turning the screws B and C, set the database D with respect to the
base E, as shown in Fig. 14. When adjusting the screws B and C are not
allowed to touch the surface with a screwdriver heads.ADJUSTING THE HEIGHT BMG
In playback mode, rotate the screw A or until the bend ribbon at the
bottom of the post of P4, and then turn the screw in the opposite
direction until the disappearance of knee tape. Attach the oscilloscope
to the output audio channel, and turning the screw C, we achieve maximum
signal. The bottom edge of tape should be above the lower edge of the
magnetic sinhrogolovki BMG approximately 0.25 mm.EXACT ADJUSTMENT OF THE HEIGHT BMG
If the position of tape does not match the above, then for BMG
lifting screw is rotated a counterclockwise until you bend ribbon at the
bottom of the post of P4. Then turn the screw in clockwise until the
disappearance of the bend the tape, and screw C until the maximum
amplitude of the signal. To lower BMG screws rotate in the same sequence
in a clockwise direction.ALIGN BMG Horizontal
Set the tracking to the middle position, while pressing the TRACKING
"+" and "-" on the remote while playing a reference recording. Connect
the oscilloscope to the amplifier signal video heads (RF SIGNAL). Weaken
the screws holding the base E BMG to the chassis and turn the base, we
achieve maximum value envelope of the RF-signal.
After that anchoring base E screws.MODE Self-Test
In video recorders (VTR) provides the function of self-diagnostics,
which provides, in case of malfunction, the displayed information in the
form of a code indicating a fault.
The list of codes is given in Table 1.
CodeThe reasonVerification (correction)
|U10||The formation of dew||Wait until it disappears|
|H01||Does not rotate SHIRBRIG||Check the motor control circuit SHIRBRIG|
|H02||No tape in the cassette podmatyvaetsya during raspravki except mode "Eject"||Check the control circuit of the drive shaft|
|F03||The mechanism is locked during mode switching, but the regime "Eject"||1. Check motor load control circuit|
2. Check the phase synchronization mechanism
3. Check switch
|F04||Mechanism is blocked during raspravki tape||1. Check motor load control circuit|
2. Check the phase synchronization mechanism
|F05||No tape podmatyvaetsya during raspravki mode "Eject"||1. Check the control circuit engine drive shaft|
2. Check the operation of sensor nodes podkatushechnyh rotation (the presence of pulses)
|F06||Mechanism is blocked after raspravki tape mode "Eject"||1. Check motor load control circuit|
2. Check the phase synchronization cassette
|F07||Supply voltage record does not show up in record mode||Check the power supply circuit for the circuit record|
|F08||Supply voltage recording appears, except the recording mode||Check the power supply circuit for the circuit record|
|F09||No transfer of a clock signal between the microcontroller and the chip timer||Check the path passing the clock signal|
Table 1: Error codesSERVICE MODE
Service mode allows you to verify the operation of various units of
VM. In this case, the display shows information in the form of
facilities and rooms service mode data service, which allows to detect
faults and, thus, reduce the repair time.
Entry into service mode by simultaneously pressing the "FF" and
"Eject" (or turning the handle to position "FF" and click "Eject") on
the front panel of the VM. Switching service modes implemented in the
The display shows information in the form of four (or five) digits.
The first digit (a digit hour display) indicates which of the seven
service modes the machine. The second and third digits (digits in
minutes) - this service data indicating a position to verify the scheme
or mechanism. The fourth (or fourth and fifth - 01, 02, etc.) figure (in
the discharge of seconds) - is the number of service data that
indicates in any scheme to be a problem.
Customer information is not dependent on service conditions and
stored in memory after you turn off the VM from the network. Deriving
this information to the display is carried out in service mode 2.
Consider the appointment of service modes.
Checks the tape protection schemes, ie Work
emitting diode and photodetectors beginning and end of the tape by
blocking the radiation on the photocell.
Checks the circuit switch modes in the transition
mechanism from one position to another with an indication of the
mechanism in the form of service data.
Checks the circuit switch mode after completion of the transition mechanism from one position to another.
Checks of the control buttons on the display should
appear on the index (in the ranks of service data), corresponding to
each of the buttons.
Calibrated work of motor control circuit of the drive shaft, ie, transmission of commands from the microcontroller (MC).
Inspects the work of the motor control circuit SHIRBRIG.
Checks of the engine load. When the button is
pressed "Play", the engine load is rotated in the direction of loading.
When the button is pressed "Stop", the motor rotates in the direction of
discharge. This mode can be indicated by an unlimited time with power.
Non-service data in various modes and their meanings are given in Table
2. Non-service information and their values are given in Table 3.
Room service modeNote: to check the package service dataCodes of service dataValueNotes
|1|| ||00||Radiation were found at both photodetectors||The tape is not required|
| || ||01||Blocked by radiation at the photodetector end of the tape (left)|| |
| || ||02||Blocked by radiation at the photodetector beginning of the tape (right)|| |
| || ||03||Radiation is fed into both the photodetector|| |
|2|| ||00||Cassette is unloaded||Requires tape|
1 Stop-3: The pressure roller is pressed against the drive shaft
2 Stop: pinch roller is spaced from the drive shaft.
To check the status of the mechanism and timing see Fig. 1
| || ||01||The cassette is loaded|| |
| || ||02||Rev, Rev Slow|| |
| || ||03||Filling, raspravka tape (middle position)|| |
| || ||04||Play / Rec, Still / Pause, Cue, Fwd Slow, Stop-31|| |
| || ||05||Stop2|| |
| || ||06||FF / Rew|| |
| || ||07||Intermediate position|| |
|3||During the transition mechanism from one position to another service data are not controlled||00||Any indication, other than "00" at the end of the operation means a fault in the circuit switching mode or system||Requires tape|
|4||Indication of number of service data only when the button is pressed|| ||The tape is not required|
|5||Controlled only by the left-hand figure||81||Indication 8, 9, U, A, -, n, L, and the lack of |
indication means that the MC had received information about passing
|Requires tape. If the display shows other than those indicated in the list, it means the failure of the scheme|
| ||Controlled only by the right-hand figure||87||Display of 1, 2, 3, 4, 6, 7 marks the command "Cue", "FF", "Fwd Slow"|| |
| ||Controlled only by the right-hand figure||8A||Indication 8, 9, U, A, -, n, L, and the lack of indication marks the commands "Rev", "Rew", "Rev Slow"|| |
|6||Controlled only by the left-hand figure||10||Display of 1, 3, 5, 7, 9, A, and nothing is displayed on the passing of the command rotation of the engine SHIRBRIG|| |
Table 2 The value of codes of service dataNotes:
1. In some models, the VM no code "U10", "F07" and "F08".
2. Code "U10" is displayed only when the power is.
3. When the lights code "F" or "H" powered the VM is automatically turned off. When power display fault code disappears.
4. Fault code stored in memory and microprocessor timer is stored in
it when disconnected from the VM network. If you repeat Mr. include
trouble code (in the form of one or two digits in the discharge of
seconds) can be displayed by moving the VM to service mode 2. If you
have any new fault in the memory is stored only by its code.
5. To erase the DTC from the memory to simultaneously push the buttons "FF" and "Eject" for 5 seconds.
|0 (00)||All right|
|1 (01)||Stop cylinder|
|2 (02)||Stop tape reels|
|3 (03)||Stop, except for positions 4 or 6|
|4 (04)||Stop during raspravki tape|
|5 (05)||Abnormal rotation of the drive shaft|
|6 (06)||Stop during loading or unloading tapes|
|7 (07)||Error in the circuit supplying power to the circuit record in writing|
|8 (08)||Error in the circuit supplying power to the circuit record is not in record mode|
|9 (09)||Error in the transmission of clock pulses between the microcontroller and timer|
Table 3 The value of codes of service informationELECTRICAL ADJUSTMENTS
Depending on the VM, the list of adjustable parameters can be
changed. For electrical adjustment requires the following hardware:
- dual-trace oscilloscope with a frequency range up to 35 MHz;
- frequency with a frequency range up to 10 MHz, with the ability to measure the period;
- digital voltmeter;
- Generator video sweep signal (video scan);
- generator of sinusoidal signals;
- video generator;
- Measuring videofonogramma VFV8125H3F (PAL), VFM8080HQFP (NTSC);
- net tape VHS;
- monitor (TV);
- DC power supply.
It should be noted that, depending on the model of the VM, the list
of adjustable parameters may vary considerably. Depending on the
location of the adjustment elements may vary their item numbers. May
also differ and the conditions under which carried out one or another
regulation.[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]
Fig.15 Timing diagram mode switch [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]
Fig.16 Adjustment of switching moment heads (PG-SHIFT) [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]
Fig.17 video sweep signal [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]
Fig.18 The waveform when adjusting the frequency response videochannel [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]
Fig.19 Waveform priregulirovke Identification System SECAM
In view of the foregoing, it is not possible in this article to
describe all the possible options for electric adjustments, so we will
focus on the most common of them. Electrical adjustment procedures are
presented as Table 4.