NATIONAL |
NV300 |
Any Function Lights Up Power On Intermittently Changes Mode |
Pin 8 Of Ic6005 Changes Amplitude, Normally 2.62v If Low Replace Ic6005 (upd4069ubc) |
NATIONAL |
NV300 |
Blank Raster On Tuner. |
Check C7009 (.01mfd). |
NATIONAL |
NV300 |
Buzzing In Sound With Low Sound On Recorded Programs. |
Check 17v Rail If High (18.45) Look For D/j On D1013. |
NATIONAL |
NV300 |
Capstan Motor Speed Fast |
Fault In Fg On C.Mtr |
NATIONAL |
NV300 |
Capstan Motor Wont Start When Loading Is Complete. |
If Pin 6 Of Ic6001 Stays Low Check Mode Switch. |
NATIONAL |
NV300 |
Capstan Not Locking. |
Bottom Board Plug Off. |
NATIONAL |
NV300 |
Capstan Slow Or No Go |
C2049 10/16v |
NATIONAL |
NV300 |
Capstan Speed Faulty In Record Mode Play Mode Is Ok |
Check Faulty C2034,0.1µf 100v |
NATIONAL |
NV300 |
Capstan Wont Lock. |
C2026 .22uf Cap |
NATIONAL |
NV300 |
Clock Display Very Dim |
D7511 Leaking |
NATIONAL |
NV300 |
Distorted Sound On Playback. |
Change Q4014. |
NATIONAL |
NV300 |
Door Stays Up (ejects) |
Lever Broken. Q6025 To Q6030 Or Ic6005 |
NATIONAL |
NV300 |
Drum Hunts. Poor Pic Like Heads |
C2003 10/16v |
NATIONAL |
NV300 |
Drum Speed Int |
C2022,c2023,c2026 2.2uf/50v |
NATIONAL |
NV300 |
Drum Wont Go. Play Mode Wont Load. |
Check Q6002 (qsb641) |
NATIONAL |
NV300 |
Function Buttons Not Operational Except Eject. |
O/c Remote Jack. |
NATIONAL |
NV300 |
Goes In To Ff When Lid Closed |
Plug From Reel Sensor Off. Lhs Rear 2pin |
NATIONAL |
NV300 |
Goes Into F.F. When Door Closed With No Tape In. |
Bottom Board Plug Has Come Off. |
NATIONAL |
NV300 |
Hum In Video And Audio In Playback, Sound Wows, Hum In Ee |
C1002 (2200 Uf) O/c |
NATIONAL |
NV300 |
Hum In Video/ee.Capstan Wont Lock. |
C1002 2200uf Cap And C2026 .22uf Cap |
NATIONAL |
NV300 |
Int Failure To Record The Audio Track. |
Replace Q4003, D4001, D4002, 2sb642rs/2sa564a. |
NATIONAL |
NV300 |
Int Leds Come On |
Ic6005 4069 |
NATIONAL |
NV300 |
Int Non Erasure Of Previous Sound Track. Chroma Sig. Remain |
Look For D.J On Bias Osc Q4014. |
NATIONAL |
NV300 |
Int Wont Go Into Record, Or Stops Recording |
Record Tab Switch Vsm0043 |
NATIONAL |
NV300 |
Int Wont Start Drum |
Replace C2026, 2027, 2028 .22µ 50v Caps |
NATIONAL |
NV300 |
Interm. Not Rec. Audio. No Audio Record. |
Solder Wire From Connector Bp6009 Pin 1 Directly Onto Pcb. |
NATIONAL |
NV300 |
Mechanical Mode Switch Check. |
Pins Of Bp6003 Should Go Low. stop Mode - 5, Laced Up Play Or Record - 1, F.Fwd. Rew. - 4, Record Pause - 3, Eject - 6. |
NATIONAL |
NV300 |
Missing 13v Rail |
R1006 1O Fuseable |
NATIONAL |
NV300 |
Mode Sele. Switch Wont Return To Normal Pos.Cass Wont Engag |
Check Q6010, Q6026, Q6028, Q6029 And R6023, R6024. |
NATIONAL |
NV300 |
No 18 V Capstan Motor |
R1010 (3O3), D1007 |
NATIONAL |
NV300 |
No Capstan 18v |
Check R1010 (3.3ohm). |
NATIONAL |
NV300 |
No Clock |
Ic7501 Mn1435vxb |
NATIONAL |
NV300 |
No Clock Or Channel Display. |
Change Ic7502(an5033) |
NATIONAL |
NV300 |
No Drum |
Q6002 2sb641 |
NATIONAL |
NV300 |
No Erase. Bias May Be Int. |
C24 10 Vfd 16v Int. |
NATIONAL |
NV300 |
No Functions |
Q 6008 |
NATIONAL |
NV300 |
No Functions Ex Eject |
Remote Control Socket Vej0229 |
NATIONAL |
NV300 |
No Functions Operating |
Change Q6008 |
NATIONAL |
NV300 |
No Go. |
Timer Record Switch. |
NATIONAL |
NV300 |
No Picture. Horizontal Lines, Wowing Sound. |
Change Ic2003. |
NATIONAL |
NV300 |
No Play, Eject Etc. |
Cass. "in" Switch (dirty). |
NATIONAL |
NV300 |
No Power. No Functions. |
Check Remote Control Socket. |
NATIONAL |
NV300 |
No Reel Drive |
Ic6006 µpc358, Motor Myn13v5l |
NATIONAL |
NV300 |
No Reel Motor Drive. |
Pin 7 Of Ic6006 Should Read 14.2v Disconnect Pins 5 And 6 If Then Ok Replace Icupc358c. |
NATIONAL |
NV300 |
No Regulated 13v |
Check Q6002 (qsb641) |
NATIONAL |
NV300 |
No Tape Functions. |
Check And Replace Load Motor Drive Transistors. |
NATIONAL |
NV300 |
No Tuner In Ee, Or Channel Indication |
R7020 3O9 On Demodulator Pcb |
NATIONAL |
NV300 |
No Video In Ee Mode |
Q703 2sd945 |
NATIONAL |
NV300 |
No Video In Play |
Q3022 2sd636 |
NATIONAL |
NV300 |
No Video In Record |
Q3017 2sb641 |
NATIONAL |
NV300 |
No Video On Playback, Blank Raster Only. |
Check Q3022 (2sd636). |
NATIONAL |
NV300 |
No Video On Tuner. |
Check Q3017 (2sb641). |
NATIONAL |
NV300 |
Not Recording Or Erasing |
Q6005 2sa719 |
NATIONAL |
NV300 |
Not Tunning Stations |
R7019, D7006 |
NATIONAL |
NV300 |
Picture Fuzzy In Playback And Ee Through Rf Out Only. video Out O.K. |
Replace Faulty Capacitors C9, C4, In Rf Modulator. (not Rf Box Where Leads Go In). |
NATIONAL |
NV300 |
Plays For A While Then Stops. |
Mode Switch. |
NATIONAL |
NV300 |
Poor Or No Lum In Play |
C3007 10µf/16v D3012 |
NATIONAL |
NV300 |
Records Low Audio On New Tapes But Loud Audio On Old Tapes. |
Replace Audio Control Stack. |
NATIONAL |
NV300 |
Rewinds And Ejects Intermittently. |
Change Q6010 (2sd636) |
NATIONAL |
NV300 |
Slow Rewind |
Clean Supply Reel Shaft |
NATIONAL |
NV300 |
Snatching Tape In Review |
Excessive Wear In Reel Idler |
NATIONAL |
NV300 |
Stays In The Eject Mode And Wont Accept Tapes. |
Change/replace All Four Q6025, Q6028, Q6029, Q6030 And Ic6005 (upd4069ubc). |
NATIONAL |
NV300 |
Supply Voltage 15 V Low |
C1003 3300uf25v |
NATIONAL |
NV300 |
Tape Speeds Increases In Pause Mode. |
Change Qr201 (dtc124a) In Noise Advance Pack. |
NATIONAL |
NV300 |
Trouble With Tape In Review |
Lower Drum Worn Sticking To Tape Polish |
NATIONAL |
NV300 |
Tuner Not Working, No Leds On Tuning. |
Check R7020 (3.9ohm) Fuseible On Demodulator Board Also D7007. |
NATIONAL |
NV300 |
Tuner Not Working. |
Check 30v Missing On Tuning Pots Because Ic7001 S/c. |
NATIONAL |
NV300 |
Vcr Stays In Rec Mode |
Ic6005 |
NATIONAL |
NV300 |
White Flickers On E-e And Playback. |
Check 5v Line For Ripple (5mv P-p Normal) |
NATIONAL |
NV300 |
White Lines In Play, Ee |
Ripple In 5 Volt Rail |
NATIONAL |
NV300 |
Wont Go Into Mode Or Goes Berserk. |
Ic6001 (mn1405) Faulty. |
NATIONAL |
NV300 |
Wont Go Into Mode Selected, Goes Berserk In Play Mode. |
Check Faulty Ic6001 (mn1405vkf) Note These Last Three Letters Are Important, Must Replace Only With Original Part Being Replaced. |
NATIONAL |
NV300 |
Wont Lock In On Playback. |
Check Ic3003 (an6327) In Luminance Channel. |
NATIONAL |
NV300 |
Wont Play. Tape Loaded. Capstan Not Functioning. |
Replace Both Loading Belts. |
NATIONAL |
NV300 |
Wont Select Play, Eratic Tape Functions |
R6056 680O Resistors Near Bj6007 Pin 2, Shb 5.24 V No Load. |
NATIONAL |
NV300 |
Wont Tune Channels. |
R7019 O/c Tuner Board. |
NATIONAL |
NV3000 |
Capstan Motor On Ay All Times. |
Check Q1016, 2sd946, Under Shield On Main Pcb. Cap. Stop. Low Should Be At Base Of Q1016. |
NATIONAL |
NV3000 |
Cuts Out In Play/fr/ff Ect |
Electro Leaked. B/t P13 P14 Bottom Pcb Reel Pulse Low. |
NATIONAL |
NV3000 |
Dew Sensor On At All Times. |
Suspect Ic 5, An6912, On Front System Control Pcb. |
NATIONAL |
NV3000 |
Dropout Compensator Not Operating,d/outs On Play. |
Check Delay Line Dl3001, P.No. Vld0020. Rf Envelope Should Be Present At Both Input, Pin 1, And Output, Pin 3. |
NATIONAL |
NV3000 |
Drum Motor Fails To Start, Interm. Stops During Play/rec. |
Go To The Edge Of The Main Pcb That Has Many Plugs Mounted Along It. Measure Ohms Between Pin 8 Of P9 And Pin 5 Of P15. This Should Measure Approximately 1.8 Ohms. if Measures High, Replace R2120 Mounted On Jumper Wire Between Pin 8 And Pin 5. |
NATIONAL |
NV3000 |
Int Lines In Pb. Drum Servo Fault |
Dj On Leads To Cylinder Drive Pcb |
NATIONAL |
NV3000 |
Int No Colour In Pb |
C8041 10µf/16v, Ic8004 An6342n |
NATIONAL |
NV3000 |
Int No Rewind |
Q6552 T/up Sensor |
NATIONAL |
NV3000 |
Int Traking Problems |
Check R2088 100k Preset Dj's |
NATIONAL |
NV3000 |
Lines In Picture. Mistraking. |
Replace Back Tension Band If Faulty. |
NATIONAL |
NV3000 |
No Audio In Pb |
Q4 2sd655 Leaky |
NATIONAL |
NV3000 |
No Audio In Record |
C47 10µf/16v |
NATIONAL |
NV3000 |
No Capstan |
Q2020 2sb641 |
NATIONAL |
NV3000 |
No Loading Motor |
Cap On Top Pcb 6800µf/16v Shorted |
NATIONAL |
NV3000 |
No Pic In Play, Distorted Video |
C122 10µf/50v In Tuner |
NATIONAL |
NV3000 |
Play Audio Volume Faulty. |
Check C22, 16v 10 µf And C19, 16v 10µf, In Audio Section Of Chroma Pcb. |
NATIONAL |
NV3000 |
Stops Int |
Q6411 2sb641 On Load Mtr Pcb |
NATIONAL |
NV3000 |
Turns Off After Several Sec's |
R6417 3O9 Fuse Res. Load Mtr Pcb |
NATIONAL |
NV333 |
2sc2671 Transistor Used In The Booster Amp.,is Trouble . |
Repair Kit, Part No. Vvk4059, Which Consists Of A 2sc2671 Transistor Plus Two Ma161c Diodes And Fitting Instructions. |
NATIONAL |
NV333 |
Buzzing Sound. E-e Normal.Recording Sound Very Low, Buzzing |
Change D1013. |
NATIONAL |
NV333 |
Cant Tune Stations In, When In E-e Mode. |
Check Tuner. |
NATIONAL |
NV333 |
Capstan Runs Too Fast. |
Check Faulty Fg In Capstan Motor. |
NATIONAL |
NV333 |
Capstan Speed Varies, Sometimes Intermittently. |
Monitor The Capstan Fg Pulses At Pin 5 Of P6001. If The Pulses Disappear Intermittently, Suspect A Faulty Fg Generator. This Is Within The Capstan Motor - Check The Interconnections First. |
NATIONAL |
NV333 |
Capstan Speed Wanders In Playback. |
Check Whether Tracking Control R2064 O/c. |
NATIONAL |
NV333 |
Cass. Wont Eject, Or Carry Out Deck Functions. |
Suspect The Mode Switch. |
NATIONAL |
NV333 |
Cassette Carriage Ascends Too Quickly. |
Teeth In Damper Unit Worn. Part No. Vdg0100. |
NATIONAL |
NV333 |
Clock Failure With No Display. |
Check 100 Ohm Safety Resistor (r7632 In Nv 366), Check Back Up Battery Is Not Leaking. |
NATIONAL |
NV333 |
Clock Not Lighting, Capstan Motor Not Turning. |
No 18v Due To Q1002 (2sd973) Being O/c. |
NATIONAL |
NV333 |
Clock Wont Relight After Mains Supply Interruption. |
Change Ic7501. |
NATIONAL |
NV333 |
Distorted Sound With Corrugated Verticals. |
Thoroughly Clean The Erase Head - Replace If Necessary. Can Also Be Caused By A Worn Audio/control Head (vbr0050). |
NATIONAL |
NV333 |
Drum And Capstan Servos Pulsing And Out-of-sync. |
Check R2017 Is Dirty. |
NATIONAL |
NV333 |
Excessive Noise In The Load And Unload Modes. |
Replace Reel Idler Arm Vxl0997. |
NATIONAL |
NV333 |
Failure To Eject. |
Check Switch, If Ok, Check C6011 (18µf) And Ic6002 (m53216p). |
NATIONAL |
NV333 |
Failure To Record The Sound. |
Change The Str1096 Regulator Ic1001 In The Power Supply. |
NATIONAL |
NV333 |
Goes Into F.F. As Soon As The Try Is Closed. |
Faulty Supply Reel Sensor. |
NATIONAL |
NV333 |
Head Switching Line Runs Through Picture. |
50hz Reference Switched On During Recorded Because Ic8004 (an6342n) Faulty. |
NATIONAL |
NV333 |
Hum On E-e Sound, Amplified To An Obliterating Buzz On Rec. |
Check For Hum On The 17v Rail. If Present D1013 (1ss16) Faulty. |
NATIONAL |
NV333 |
Hum On Sound. |
Ic4001 (ta7325p) Developing Hum Internally. Check The Inputs And Outputs With Scope. |
NATIONAL |
NV333 |
In Reverse Pic. Search Mode The Tape Loops Into Machine. |
Faulty Head Drum. (the Engraved Tracks Wear Thin And The Tape Sticks). |
NATIONAL |
NV333 |
Inter. Head Switching Line Runs Through Pic.,drum Speed Var |
Vss Signal Missing Due To A D/j At Pin 1 Of Ic301. |
NATIONAL |
NV333 |
Interm. Loss Of Colour Or Interm. Colour Bars On Screen. |
Check If The Pulses At Tp8006 Are Less Than 6v P-p, Adjust R8036 To Correct. |
NATIONAL |
NV333 |
Intermittent Audio Erase. |
Remove R4049 (4.7) In The Bias Oscillator Circuit And Replace With A Shorting Link. |
NATIONAL |
NV333 |
Intermittent Chroma On Record. |
Connect A Fast-acting Diode (ma161 Or Ma162) Between Pins 11 And 12 Of Ic6003 On The Syscon Board, Cathode To Pin 11. |
NATIONAL |
NV333 |
Intermittent Failure To Eject Tape. |
Check Key Scan Inhibited Due To C6011 (ecqv05184jz) Or Ic6002 (m53216p) Faulty. |
NATIONAL |
NV333 |
Intermittent Loss Of Capstan Lock In The Record Mode. |
Suspect An Intermittent Fault In Ic2003 (upc1505c). |
NATIONAL |
NV333 |
Intermittently Cuts Out On Deck Functions. |
The Counter Has A Hall-effect Sensor. Any Of The Following Can Cause The Complaint: The Reel Idler, Idler Arm, Counter Belt, A Tight Take-up Reel, The Hall-effect Device Faulty Or Too Far From The Magnet, Or A Defective Reel Motor. |
NATIONAL |
NV333 |
Knocking Noise On Fast Forward. |
Noise Affected By Pressure On The Cassette. Lubricate The Spool Shafts. |
NATIONAL |
NV333 |
Lid Wont Stay Down. Seems To Be Permanently In Eject Mode. |
Check The Operation Of The Cassette Down And Loading- end Switches, Mode Select Switch. |
NATIONAL |
NV333 |
Loading Motor Continues To Run. Stays In Loaded Condition. |
A Very Common Cause Of This Problem Is Slippage Of Loading Belt 2. If Replacing This Doesn't Provide A Cure, Suspect Misadjustment Of (or Fault In) The Mode Switch. Its Mechanical Adjustment Is Very Critical. |
NATIONAL |
NV333 |
Loading Motor Stops During Loading. |
Ic6005 (upd4069ubc) Probably Faulty. Also Check That C6008/9 Have Been Changed From 100pf To 300pf. |
NATIONAL |
NV333 |
Machine Intermit. Stops And Rewinds During P/back,or Rec. |
Supply Phototransistor Q1503 (pn150nv) Faulty. Sometimes Ic6004 (an6912) Is Respnsible. |
NATIONAL |
NV333 |
Machine Wont Switch On. |
Power On/off At Pin 3 Of P1003 Not Switching Due To A Faulty M53216p Chip (ic6002) In The Syscon Circuit. |
NATIONAL |
NV333 |
No Capstan Lock In Playback. |
Check The D.C. Level At Pin 16 Of Ic2003 (upc1505c). If Low Suspect No 9v Supply As Q6003 (2sa719) In The Syscon Circuit Is O/c. |
NATIONAL |
NV333 |
No Capstan Motor Rotation. |
Check Ry1 On The Servo Panel Faulty. |
NATIONAL |
NV333 |
No Chroma In The Record Mode. |
If The Chroma Is Present At Tp8003 Check At Pin 8 Of Ic8001 (an6360). If The Chroma Is Missing Here And The D.C Level Is High (should Be Aspprox. 4.5v) D8005 (ma165) Is Probably Leaky - It Links Ic8001 To The Colour Killer In Ic8003. |
NATIONAL |
NV333 |
No Clock Display. |
Ic7501 On The Front Panel Is Faulty. In The Nv333 It's Type Mn1435vxb. Getting The Suffix Right Is Vital. |
NATIONAL |
NV333 |
No Deck Functions. |
Cassette Down Switch On Eject Latching Assembly Dirty Or Worn. Part No.Vsh0013. |
NATIONAL |
NV333 |
No Eject Damping - The Gear Teeth Inside Damper Unit Break. |
Replace The Unit. |
NATIONAL |
NV333 |
No Field Lock In Playback. |
Change Ic3003 (an6327) |
NATIONAL |
NV333 |
No Field Sync On Playback. |
Check The Signal At Pin 1 Of Ic3003 (an6327). If Missing, Suspect Ic3003. The Signal Should Be 2v P-p. If Less Than 1v P-p, Change Ic3003. |
NATIONAL |
NV333 |
No Functions Except Eject. |
Check For Dirty Contacts On Thr Cassette-in Switch. |
NATIONAL |
NV333 |
No Go. |
If Pin 8 (power Off) Of Ic6001 Is High, Q6010 (2sb641) Faulty. |
NATIONAL |
NV333 |
No Go. |
No 9v And 6v Outputs From The Str1096 Chip Ic1001 At Pins 4 And 5 Respectively. Check Whether The Unregulated 15v Supply Is Present At Pin 1. If This Is Present And The Supplies Dont Return When The Loads Are Disconnected Ic1001 Is Faulty. |
NATIONAL |
NV333 |
No Playback Colour, Unlocked Colour Flickering Occasionally |
If Pin 9 Is Linked To +5v And Colour Comes Back Ic3002 Faulty. |
NATIONAL |
NV333 |
No Power After 10 Sec., With No Loading. |
No Loading Motor Drive As Ic6005 (upd4069ubc), Q6026 (2sb819) And Q6029 (2sd1051) Faulty. Change C6008 And C6009 (300pf)> |
NATIONAL |
NV333 |
No Reel Drive. |
No Motor Drive As Q6022 (2sb641) And Q6023 (2sd12730) S/c. |
NATIONAL |
NV333 |
No Rewind Or Fast Forward With No Cue Or Review. |
Check Q6023's Emitter For Dry Joint. |
NATIONAL |
NV333 |
No Rewind Or Fast Forward. |
D1009 (ma165 Or 1ss133) Faulty. |
NATIONAL |
NV333 |
No Tuner Operation Or Channel Leds. |
Check 3.9 , 0.5w Safety Resistor R7020 Is Probably O/c. |
NATIONAL |
NV333 |
No Tunning. |
Tuning Voltage Missing R7019 (100 Ohm, 0.25w) O/c. The Upc574jk Stabilizer Ic7001 And Q7005 (2sb642) Probably S/c. |
NATIONAL |
NV333 |
Permanent Eject. |
Change Q6028. |
NATIONAL |
NV333 |
Poor Field Sync On Playback Of Own Rec. Hum, Ripple On Edge |
Check Hum On Thr 1.T. Lines Because One Of The Em1z Rectifier Diodes D1001-4 Is O/c. |
NATIONAL |
NV333 |
Poor Recording And Sound Coming Through From Other Channel. |
Dry-joints On The Bias Oscillator Transistors Q4014. |
NATIONAL |
NV333 |
See Nv366 |
|
NATIONAL |
NV333 |
Sluggish Rewind. |
Check If The Reel Idler Is Ok Check The Supply Reel - it's Probably Tight On Its Shaft (lubricate As Necessary). |
NATIONAL |
NV333 |
Sometimes Wont Rec. Or Play. F.F. And Rew. Ok. |
Set Up The Cam Gear And Action Gear As Per The Manual. Clean The Belt And The Pulley Wheels. |
NATIONAL |
NV333 |
Squeaking Capstan. |
Put Into The Pause Mode To Confirm. This Fault Can Be Caused Either By Worn Bearings In The Capstan Motor Itself (max13v9lp), Or By A Dry Flywheel Bearing. |
NATIONAL |
NV333 |
Squeaking Noise Which Stops In Pause. |
Noisy Capstan Motor. |
NATIONAL |
NV333 |
Squeaks When Loading Or Unloading. |
Lubricate Loading Roller Bearings. |
NATIONAL |
NV333 |
Take-up Spool Rotates In The Stop Mode. |
Check For Dirty Connections At The Supply Photosensor Connector P6010. |
NATIONAL |
NV333 |
Tape Is Not Reeled Back Into The Cassette During Unloading. |
Replace The Reel Idler (vxp0401) And Check The State Of The Intermediate Geaar (vdg0017). |
NATIONAL |
NV333 |
Tape Loops Into The Machine In The Review Mode. |
This Is Caused By Excessive Friction At The Drum. It's Sometimes Due To The Grooves On The Drum Being Worn, Or A Worn Lower Drum. |
NATIONAL |
NV333 |
Tape Snatching In The Review Mode. |
Check Excessive Play In The Joints Of The Reel Idler Arm (vxl0997). If A Replacement Doesn't Provide A Cure, Fit A Washer On The Joint. |
NATIONAL |
NV333 |
Tape Will Not Unlace Or Will Not Complete Lacing. |
Replace The Large Loading Belt And Check The Others. |
NATIONAL |
NV333 |
Tuning Drift. |
Remove C7010 (0.22uf) On The Demodulator Pcb. |
NATIONAL |
NV333 |
Wavering Playback Sound. |
Check For Worn Capstan Motor. |
NATIONAL |
NV333 |
When Cass Is Loaded The Machine Wont Respond To Any Command |
Check The Cassette-down Switch Under The Main Board. |
NATIONAL |
NV333 |
When Review Is Selected The Machine Ejects The Cassette. |
Check For Faulty Or Misaligned Mode Switch. |
NATIONAL |
NV333 |
Whine Or Whistle From Direct-drive Unit. |
Check The Discharge Angle At The Top Of The Drum Was Worn. Sometimes The Dd Motor Bearings Become Noisy. |
NATIONAL |
NV333 |
Won't Switch Off, Even When Timer Button Is Pressed. |
The 2.5a Fuse On The Mains Transformer Pcb Is O/c. Change Ic6002 (m53216p). |
NATIONAL |
NV333 |
Won't Tune In. |
No 30v Supply At Pin 10 Of P7005 Because D7005 (ma26wcb) In The 30v Regulator Circuit On The Demodulator Pcb Is S/c. |
NATIONAL |
NV333 |
Wont Eject And No Other Functions Work. |
Check Eject Switch Sw6501. |
NATIONAL |
NV333 |
Wont Erase Prev. Sound Track. Pic. Has Chroma Washover. |
Check For No Erase Bias, Probanly Because Of D/j's On Q4014 And T4001 On The Audio Panel. If The Problem Persists, Or Low Bias Seems To Be Incurable, Link Across R4049 (4.7mfd) In Q4014's Emitter Circuit. |
NATIONAL |
NV333 |
Wont Lock In The Playback Mode. |
Q6003 O/c. |
NATIONAL |
NV333 |
Wont Rec In Colour. Replays Prerecorded Tapes In Colour. |
D8005 (ma165) Which Turned Out To Be Leaky. |
NATIONAL |
NV366 |
Bottom Half Of Pic., Covered In White Noise Spots, Flicker. |
Replace Rl3501 & Rl3502. |
NATIONAL |
NV366 |
Cass. Stuck, Only Clock, Programmer Work. |
Sitch Ing Off The Power For A Long Time Restores Normal Operation Until Next Lock-up. Check The Syscon Microcomputer Chip That Its 5v Supply (pin 39) Is Present And Correct, With No Ripple/hash. If Ok Change (mn1405vkk). |
NATIONAL |
NV366 |
Channel Change Faulty, Wrong Led Lights Up.More When Cold. |
Replace Q7553 (2sd637) With Improved Typ[e 2sd637s Or T Or Type 2sc1685s Or T. In Addition Fit A 2.2k Resistor In Unused Position R7565. |
NATIONAL |
NV366 |
Check 3.3mfd 2.0v (3 Off). |
Leak Goo Into Board, Sparks When Hit With Soldering Iron. Check Also R1101. .12 Ohms For O/c. |
NATIONAL |
NV366 |
Cue/review Modes Are Released And Returns To Play. |
Check Dirty Contacts On Switching Relays Rl3501/2. Replace Both (part No. Vsy2029) |
NATIONAL |
NV366 |
Interm. Noisy Picture,tracking Control Has No Effect. |
Replace Faulty Switching Relays. |
NATIONAL |
NV366 |
Intermittently Incorrect Capstan Speed. |
Check The Capstan Fg Signal At Tp2007. When Motor Is Gently Tapped The Speed Corrects Itself. Change Motor - (the Capstan Fg Generator Is Built Into The Motor.) |
NATIONAL |
NV366 |
No Clock Display. |
Ic7501 On The Front Panel Is Faulty In The Nv366, It Is A Mn1455bub. Getting The Suffix Right Is Vital. |
NATIONAL |
NV366 |
Pic. Noisy After The Still. |
Check Dirty Contacts On Switching Relays Rl3501/2. Replace Both (part No. Vsy2029) |
NATIONAL |
NV366 |
Saturated Colours From Pre- Recorded Tapes Only. |
Check Back Tension Should Be 25/30 Grams. |
NATIONAL |
NV366 |
See Nv333 |
|
NATIONAL |
NV366 |
Still Mode Pic. Has Black Spikes. |
Replace C3529 And C3530 With 40pf Type Ecv1zw40x53n Capacitors And Change R3522 To 100. Fit A 22pf, 50v Capacitor (c3535) Across Pins 1 And 2 Of P002. Readjust The Head Amplifier Peak Frequency (tp3508) To 4.9 Mhz Instead Of 4.5mhz. |
NATIONAL |
NV366 |
This Machine Doesn't Like Hg Tapes. |
Machine Will Squeal In Record And Playback. E180 Tapes Work Ok. |