tandberg 3400x_3500x_3600xd-servicemanual 维修电路原理图.PDF

IffiEffi SERVICE MANUAL SoooxD CONTENTS l. l.l r.2 , 2.1 99 3. 3.1 3.2 3.3 3.4 c.c 3.6 4. 4.1 4.2 4.3 4.4 4.5 5. 5.1 5.2 5.3 5.4 c.5 6. 6.1 6.2 6.3 6.4 6.5 7. 7.1 19 7.3 8. 8.1 8.2 8.3 8.4 9. 9.1 9.2 10. 11. 11.1 rt.2 11.3 Page Introduction. .,.3 General .3 Removingthe toppanel . .3 Maintenance. .,.,.4 Cleaningthetapepath. .4 Lubrication .4 Mechanicalchecksandadjustments. .5 Checking the take-up force and winding force. . . . . . 5 Adjustingthetake-upforce. .5 Adjustingthe windingforce. .6 Adjustingthebrakes .8 Rubberdrivebelt .8 Pressurepadarm .9 Tapepath .10 Capstan .10 Headparallelism. .10 Tape guide posts and guide screws. . . . . . .11 Pinchroller .11 Flutterroller. .12 Head alignment with Tandberg test tapes, four tracks . . . . .13 Playbackhead. .13 Recordhead. .13 Height adjustmentby trackmeasurement. .13 Biashead .I4 Erasehead .I4 Head alignment without Tandberg test tapes, four tracks . . . . . . .15 Playbackhead. .15 Recordhead. .15 Biashead .15 Erasehead. .15 Aligning the hum shield for the playback head . . . . .15 Headalignment,two tracks .16 Playbackhead. .16 Recordhead. .16 Erasehead .17 Circuits .77 Oscillator. . . .I7 Photoend-stop .I7 Record and playback frequency responses . . .18 Faultinthetotalresponse curve,one channel. .19 Modifications. .20 Changingthelinevoltageand frequency. .20 Changing from four tracks to two tracks version . . . .20 Blockdiagrams .20 Electricaladjustments. .22 Outputamplifiers (3400X) .22 Dolby*leveladjustments (3600XD). .22 Adjustments,allmodels. .23 Circuitdiagrams . from page24 * The word Dolby is a Trade Mark of Dolby Laboratories Inc., USA -.- - t a 1.INTRODUCTION - 1.1 GENERAL Only LH (Low Noise/High Output) tape should be used for recording. Make sure that the heads and tape path are clean. To check the heads: - l. Remove the front head cover by depressing the spring loaded buttons at both ends and lifting the cover straight upwards. 2. Remove the back cover by depressing the spring on its rear side and lifting straight upwards. When electrical adjustments are to be made, the bottom panel must be removed. The tape path must be degaussed both before and after adjustment. Do not switch off the degausser until it is about 3 feet from the tape path. To make magnetized parts of the tape visible, dip the tape in Magna See. This is a mixture of iron oxide powder and alcohol. Iron oxide powder can be obtained from our service department. A NOTE! All paragraphs in this manual are valid for: Model 3400X, from serial No. 4300 000 Model 3500X, all decks Model 3600XD, from serial No. 4200 000 1.2 REMOVING THE TOP PANEL Remove the head covers and the speed selector knob. Then remove the screws as shown in Figure 1.1. Removal of the top panel will usually only be necessary for checking and adjustment of clutches and other parts in the drive mechanism. Fi4.1.1. Top panel screu)s .HHs.n - 2.MAINTENANCE Fig. 2.1 Cleaning the taPe Path 2.1 CLEANING THE TAPE PATH It is important that the tape path is clean before adjustments are made. If the heads and guide posts have been adjusted, the tape path must be de- magnetized. Cleaning should be carried out with cotton-bud sticks (Q-tips) moistened with pure alcohol or methylated spirit. A special cleaning kit called Tandberg Professional Tape Head Cleaner is also available. Aerosol sprays indented for video tape recorders may be used, but it is not sufficient just to spray the parts; cotton-bud sticks must also be used. Obstinate deposits on guide posts should be first well softened with the cleaning agent and then removed with the aid of a toothpick. The pinch roller A should be cleaned if the tape runs unevenly or if there are visible deposits on the roller (4 to 6 times a year should be sufficient, even if the tape recorder is much used). Make sure that the pinch roller is dry after cleaning. 2.2 LUBRICATION NOTEI Do not usc more than one drop of oil on each bearing, as excessive oil may penetrate into the drive mechanism and disturb friction conditions. The turntables, flywheel and transfer wheel are mounted in selflubricating bearings and should not need attention under normal conditions. If for some reason lubrication appears to be necessary, use Teresso oil No 43 or 47 from Esso. The motor should be lubricated after every 3000 hours of operation. Apply only one drop of Teresso oil No. 43 or 47 from Esso. ffi -= o t A 3. 3.2 3.1 MECHANICAL CHECKS AND ADJUSTMENTS CHECKING THE TAKE-UP FORCE AND WINDING FORCE Fig. 3.1 Checking the winding force. A 7 reel with a hole drilled in it 80 mm from the hub hole is required together with a torque gauge. Insert the leg of the torque gauge into the drilled hole. The reel should be allowed to rotate slowly in the direction of the clutch torque while the measurements are performed to obtain the speci- fied values. see table 3.2. ADJUSTING THE TAKE-UP FORCE Fig. 3.3 Adjusting the take-up force. NOTE ! Do not touche the textile side of the belt with your fingers. The rubber drive belt does not move during normal forward drive. This is because a textile belt pro- vides the take-up force via a drive wheel mounted behind the take-up turntable. Adjust the take-up force by moving the spring, see Figure 3.3. If the winding force is not correct it should be adjusted as explained on the next page. TurntableOperating lever position Playback or wind force Rieht 25- 30 e* Right 9o-2so g* Left 90-250 p* Table 3.2 Clutch torque x It is normal for the winding force to increase 20-30% after the machine has been in conrinuous operation for some time. O 3.3ADJUSTING THE WINDING FORCE f-x ! a The lifting arms for the drive belt should be adjusted when the joystick is in NEUTRAL (nrid- position). Adjust for I mm clearance with flat pliers as shown in Figure 3.10. Adjust A first and the B. 3.6 PRESSURE PAD ARM With the joystick in the ) position, the tension from the pressure pad arm against the bracket should be between 80 and 100 g. This pressure should be measured as shown in Figure 3.11. Adjust by bending spring A which presses the pressure pad arm against the head. Check that the pressure pad arm is parallel when it meets the bracket. Fi9.3.10. Adjusting the clearance on the driue belt Fig.3. 1 1. lvleasuring the pressure-pressure 4.TAPE PATH 4.1 CAPSTAN Before the heads and tape guide posts are adjusted, the position of the capstan must be checked. Useipecial tool No. 5 as shown in Figure 4.1. All three legs of the special tool should rest on the upper mounting plate. If one or more of the legs dois not rest on the plate the capstan needs adjusting. To adjust the capstan, loosen the three coioured screws and adjust the capstan until all three legs of the tool rest on the plate. Tighten up the screws and check again that the legs are all touching the Plate. NOTE! The capstan will not go out of adjustment with normal use and transit. 4.2 HEAD PARALLELISM Check that the heads are parallel with the aid of a tape path gauge see Figure 42. This adjustment aflects the passage of the tape through the tape path, and where the heads are seriously out of ilignment the complete tape path must be checked, see next page. Fig. 4.1. Actjusting the capstan with special tool No 5 4N 1 s Adjust Forwards Adjust Backwards r-TIl L_J Correct Zenith Fig. 4.2. Adjustirtg with the tape path gauge (s 4.3TAPE GUIDE POSTS AND GUTDE SCREWS 4.4 PINCH ROLLER Fig. 4.3. Adjustable tape guide posts. a ; Thread a tape into the tape path. pull the joustick slowly down into the ) position and tishten the tape by rotating the left reel slowly cloikwise. Check that the tape does not come into contact with the edges of the tape guide screws. If necessarv, adjust the guide screws shown in Figure 4.3. When the machine is in the playback mode and tape is passing the heads, the tape may touch the top edges of the guide posts and guide screws, but under no circumstances should it twist or distort. The two adjustments possible on the pinch roller are parallelism and azimuth. Parallelism. Push the pressure roller arm in and check that the pinch roller is parallel with the capstan. To adjust, loosen screw A and adjust screw B (Figure 4.4) until the pinch roller and capstan are parallel. Tighten up screw A. Azimuth. Put a tape into the tape path and move the joystick to ) . Check that the tape does not distort when it has passed the pinch rbller. To adjust, loosen screw A and move bracket C (Figure 4.4) until the tape runs properly. Tighten up screw A. Fig. 4.4. Adjusting the pinch roller. A ttr 4.5 FLUTTER ROLLER Parallelism. Loosen screw A (Figure 4.5). Insert a screwdriver into the slot and move the upper bearing forwards or backwards until the flutter roller is parallel with the head front. Azimuth. Set the speed selector to 7Vz ips, put a tape into the tape path, and move the joystick to ) . Insert a screwdriver as shown in Figure 4.6 and twist it to move the flutter roller to the left until the tape just touches the top edge of the nearest tape guide post. Move the screwdriver to the position shown in Figure 4.7 and move the flutter roller carefully to the right. If the roller is correctly adjusted the tape will lift slowly upwards from the bottom part of the tape guide post and touch the upper part of the tape guide post without curling. This adjustment can be checked with a lamp placed behind the tape path. Look from the front to see light between the tape and the lower part of the tape guide post. Fig. 4.5. Adjusting the parallelisem of the flutter roller. Fig. 4.6. Adjusting the azimuth of the flutter roller. (R ,-l 17/ IE Fig. 4.7. Adjusting the azimuth of the flutter roller. ($ I 5.HEAD ALIGNMENT WITH TANDBERG TEST TAPES, FOUR TRACK NOTE! The tape path must be thoroughlv cleaned before adjustments are carried out. Use tape without any defects. If the heads have grooves caused by wear, adjustment of the heads should be avoided. Seal all screws in the tape path after the adjust- ments have been made. After replacement of a single part in the tape path, it may often be necessary to adjust the new part only. If, however, more parts have to be adjusted, a complete check and adjustment of the entire tape path must be performed. Adjustments must be carried out in the same sequence as explained in this section. 5.1 PLAYBACK HEAD Connect an a.c. voltmeter to each of the LINE OUT sockets and set the SOURCE/TAPE buttons to TAPE. Height adjustments Play back test tape No. 1. This is a full track pre- recorded tape with 1,000 Hz recorded at 7/z ips and with the area corresponding to track 3 reduced by approximately 35 dB. Adjust the height of the pla,vback head by means of scrcw A, Figr-rre 10.1, page 2l until minimum outplrt is obtained from track 3, channel R while maintaining the head-front parallel to the tapc. Azimuth adjustments Play back Tandberg test tape No. 2 at 7tl: ips (or a standard azimuth tape). Adjr,rst the azimuth posi- tion of the playback head by means of screw B, Figure 10.1 (page 2l) until maximum output on the voltmeters is obtained on both channels, or adjust for the best compromise. 5.2 RECORD HEAD Height adjustment by visual inspection Insert a new tape and set the deck to normal forward drive ( ) ). Check visually that the tape appears to run parallel with the upper track on the record head, n,ithin approximately 0.1 mm (0.04) see Figure 5.1. If necessary adjust the height with scrervs C, Figure 10.1, rvhile main- taining the head-front parallel with the tape. HeightLateral Alignment t; a J- Qf l-r t v l l ( AzimuthZenith 5.3 HEIGHT ADJUSTMENT BY TRACK MEASUREMENT Record in stereo a 1,000 Hz siqnal lvell above the normal level, first in one direction, then in the opposite dire ction. Cut off a length of tape and dip into a solution of fine-grained iron-oxide powder and alcohol (Magna See). The tracks will then be visible as four dark stripes. Figure 10.2 (page 21) sholvs the correct pattern on the tape and the patterns obtained when the head is either too high or too low. If necessary, adjust the height of the head and repeat the measurement until the patters are correct. Azimuth adjustment Load the dcck rvith a new tape and record at 33/a, tps a 12 to 13 kHz signal in stereo. Set the SOURCE/TAPE buttons to TAPE. Adjust both INPUT LEVEL potentiometers for approximately 150 mV reading on a.c. voltmeters connected to the LINE OUT sockets. Adjust the screw D (figure 10.1) for maximum output from both channels, or the best compromise. Approx.0.1 mm of upper pole piece visible above tape. - Fig. 5.1. Four track record head. tEt / 5.4 BIAS HEAD Vertical adjustment Move the operating lever slowly to the normal for- ward drive position ( I ) and check that the head- front of bias and record heads are parallel. If necessary, bend the arm of the bias head as required. Height adjustment Set the deck to the stereo screw the locking screw H turn. record mode, and un- (Figure 10.1) about one ,( 1 Connect an a.c. voltmeter across each half of the record head. Nlove the bias head up or down by means of adjustment screw M (Figure 10.1) for the highest possible reading on the voltmeter. Check that the tape runs freely in the groove in front of the bias head, and that there is sufficient clearance between the bias head and the mounting plate for the record head. If necessary, raise the bias head slightly. The height position of the bias head is not critical. Before tightening screw H, carry out the horizontal adjustment as follows. Horizontal adjustment Connect an a.c. voltmeter across each half of the record head and set the deck to the stereo record mode. Insert a screwdriver in the groove shown in Figure 5.2 and tilt the bias head to the right. Then tilt the bias head carefully by means of the screw- driver towards the left until the induced voltage (bias) in the record head increases to a maximum. Continue tilting the head towards the left until the induced voltage (bias) in the record head is redr.rced to between 10 and lSYobelow maximum. Tighten screw H while maintaining the correct horizontal position for the head. Then re-check the output voltage. If the voltage has changed notice- able, the horizontal adjustment procedure must be repeated. Fig. 5.2. Ilorizontal adjustment for the bias head. 5.5 ERASE HEAD Height adjustment By visual inspection, check that approximately 0.25 mm (0.01) of the upper half of the erase head is visible above the tape, see Figure 5.3. Insert fandberg test tape No. 9 and record on channel R a 400 Hz signal well above normal recording level. Dip the tape in a solution of fine-grained iron-oxide powder and alcohol (Ntlagna See). Check that the recorded track is positioned in the centre of the erased track, see Figure 10.3, page 21. Approx. 0.25 mm of upper ferrite core visible above tape.