National NV100 Video Cassette Recorder

[Terry Collins]

I have been given a National NV100 Video Cassette Recorder. Naturally it
doesn't work.

First problem; The tape holder keeps popping up, whether there is a tape
(VHS) inserted or not. Any clues on what to examine as to cause.

Second problem; one the rare occasion that the tape stayed down, it
would neither rewind/FF/play/etc. Transport seemed to be jammed.
Cluebies wanted.

Is it worth "repairing" this device or should I just strip it for screws
{

 

[James254]

I have been given a National NV100 Video Cassette Recorder. Naturally it
doesn't work.

First problem; The tape holder keeps popping up, whether there is a tape
(VHS) inserted or not. Any clues on what to examine as to cause.

Second problem; one the rare occasion that the tape stayed down, it
would neither rewind/FF/play/etc. Transport seemed to be jammed.
Cluebies wanted.

Is it worth "repairing" this device or should I just strip it for screws
{

Hi Terry,

Due to the age of the unit my immediate thought is strip it for screws and
chuck the leftovers in the bin. But the following may help you if time is
not an issue...

Symptom - Loads then ejects.
Remedy - Cassette down switch open circuit.

Symptom - No take-up of tape slack in the play mode.
Remedy - Remove circlip on transmitting gear unit (Run by timing belt).
Remove transmitting arm unit underneath and clean and re-grease. Please
note! In play mode take-up is done by the transmitting gear unit. In fast
forward and rewind it is done by the F/F idler assembly.

I no longer work for the company where I compiled this information, so I
can't assist you with service manuals or further information if my
suggestions didn't help.

Good luck!

 

[Terry Collins]

James254 wrote:

....snip.....

Due to the age of the unit my immediate thought is strip it for screws and
chuck the leftovers in the bin. But the following may help you if time is
not an issue...

Beautiful. Thank you. Took 5 minutes. Handles the tapes nicely. Will
give it a quality check out later.

 

[Terry Collins]

I have been given a National NV100 Video Cassette Recorder. Naturally it
doesn't work.

Okay, I've fixed the first problem { thanks to newsgroup help, but
now it "chugs". -blerk.

Inserted a tape, it rewound it for full length then FF for a short
while, then left it for a few hours and came back to it.

Insert tape, press play and it chugs ( that what is sound like) then
stops.. Rewind and FF seem to move a little, then stop. Tape is still in
the cassette. I don't have to wind it back in when it ejects.

At one stage I had disco lights (well they were all flashing red on all
the various buttons).

Fiddling with this is worth is as I'm not in the position to go out an
buy a professional video camera (which is what I need atm).

Looking for tips on what to look out (that might get it working).

TIA

 

[James254]

Okay, I've fixed the first problem { thanks to newsgroup help, but
now it "chugs". -blerk.

Inserted a tape, it rewound it for full length then FF for a short
while, then left it for a few hours and came back to it.

Insert tape, press play and it chugs ( that what is sound like) then
stops.. Rewind and FF seem to move a little, then stop. Tape is still in
the cassette. I don't have to wind it back in when it ejects.

At one stage I had disco lights (well they were all flashing red on all
the various buttons).

Fiddling with this is worth is as I'm not in the position to go out an
buy a professional video camera (which is what I need atm).

Looking for tips on what to look out (that might get it working).

TIA

Hi Terry,

I vaguely remember that all of the lights flashing at once was some sort of
error message, but I haven't made any notes on the cause. Sorry.

The "Rewind and FF seem to move a little, then stop" fault might be caused
by the following...

Symptom - Cuts off play, fast forward and rewind.
Remedy - Check the function of photo sensor under supply the take up reel
table (Part number for the sensor is ON2160). Possibly only cleaning of the
photo sensor and the underside of reel table is all that's required. Take
care not to scratch the reflective surfaces of the reel table!

Good Luck!

 

[Terry Collins]

James254 wrote:

....snip....

I vaguely remember that all of the lights flashing at once was some sort of
error message, but I haven't made any notes on the cause. Sorry.

The "Rewind and FF seem to move a little, then stop" fault might be caused
by the following...

Symptom - Cuts off play, fast forward and rewind.
Remedy - Check the function of photo sensor under supply the take up reel
table (Part number for the sensor is ON2160). Possibly only cleaning of the
photo sensor and the underside of reel table is all that's required. Take
care not to scratch the reflective surfaces of the reel table!

Bingo. Well a general blow out fixed that. I'm not sure where this
sensor is and suspect it is in a post that sticks up.

Okay, next problem (sigh). It starts to play and then stops. I can see
the arms that wrap the tape around the head/drum start to move the tape
towards the head/drum, then reverse. Next button press, they hardly move
at all.

any hints {.

I gather that these are your notes.
Unfortunately, I wasn't able to google anything on how this mechanism
works, other than a simple few lines on helical scan heads.

TIA.

 

[James254]

James254 wrote:

...snip....


Bingo. Well a general blow out fixed that. I'm not sure where this
sensor is and suspect it is in a post that sticks up.

Okay, next problem (sigh). It starts to play and then stops. I can see
the arms that wrap the tape around the head/drum start to move the tape
towards the head/drum, then reverse. Next button press, they hardly move
at all.

any hints {.

I gather that these are your notes.
Unfortunately, I wasn't able to google anything on how this mechanism
works, other than a simple few lines on helical scan heads.

TIA.

Hi Terry,

Had some problems with my ISP and their news server but they've fixed the
problem.

The "Take up reel table" is on the right hand side of the mechanism, when
you are looking at it from the front. It's the bit that fits into the
cassette to turn the tape around. The take up reel sensor is underneath the
reel table. Sometimes there not easy to remove as you've got to take brakes
and other stuff off first. A pair of circlip pliers are also required if I
remember correctly...

Mmm, could be one of two things

1. If the unit has a loading belt it could be slipping and causing lacing to
be very slow. The arms you mention should lace the tape around the drum in
about 2 - 5 seconds.

IF this unit uses a loading belt it will usually be underneath the
mechanism. It's not easy to get to if I remember correctly.

2. If the drum does not start turning (Or it's turning but the feedback
information is not reaching the right part, could be the servo IC or the
microcontroller) then this will happen.

If this is the case then you'll need a circuit diagram, my personal notes
don't cover this.

Hope this helps.

 

[Terry Collins]

James254 wrote:


...snip......

If this is the case then you'll need a circuit diagram, my personal notes
don't cover this.

Hope this helps.

Thanks for your help.

I eventually found the Sci.electronics.Repair stuff (excellent guide)
and started working through it. Finally convinved myself that it was
going to take some time (which I now don't have) and as you said a
circuit diagram. I seemed to be going in circles (problems kept coming
back). So it is now being broken down into bits - currently most is in a
large pickle jar. Not many screws, but a large number of circlips. Just
have to find a circlip pliers small enough.

The circuit board will go to a neighbourhood kid who likes to collect
bits (nice place to send all this {. Must remember to invite him over
to use the desoldering iron over the school holidays. Although I will
have to insist that he just brings circuit boards and not the TV's etc
that he and his mates have been collecting from the neighbourhood kerb.

I will build a power supply and signal splitter for the camera itself,
so it can be used as a webcam or computer capture camera. Maybe even a
"who is at the front door" cam.