I have a problem with my Sony Betamax SL HF100 VCR. After starting play
mode, I can see the video for about 2-3 seconds and then get an blue
screen, while tape transport continues. When pressing Play and FF
simultanuously, the video can be seen but vanishes, when returning to
normal play mode. All this does not happen with all tapes, there are
others, that play with no problems. Is there any circuit in these old
Betamax recorders, which disables the reproduction because of i.e. poor
sync signal? Thanks for any hints to fix the problem.

Dietrich

Head cleaning problem. Video heads mainly, but the audio/control head could
cause this also. Caution is advised - improper technique can ruin the video
head. The affected head gap on the A/C head is the lower one - Sony's were a
bit notorious for this one getting dirty.

Mark Z.


"Dietrich Steinmeier" wrote in message
...
I have a problem with my Sony Betamax SL HF100 VCR. After starting play
mode, I can see the video for about 2-3 seconds and then get an blue
screen, while tape transport continues. When pressing Play and FF
simultanuously, the video can be seen but vanishes, when returning to
normal play mode. All this does not happen with all tapes, there are
others, that play with no problems. Is there any circuit in these old
Betamax recorders, which disables the reproduction because of i.e. poor
sync signal? Thanks for any hints to fix the problem.

Dietrich

"Mark D. Zacharias" wrote:

Head cleaning problem. Video heads mainly, but the audio/control head could
cause this also. Caution is advised - improper technique can ruin the video
head. The affected head gap on the A/C head is the lower one - Sony's were a
bit notorious for this one getting dirty.

The video mute is controlled by the sync signal from the control head,
so any dirt or wear here will kill the output.

(Trust Sony to be different, everyone else used the video signal!)

(I'm just jealous because you've got an HF100 and I haven't!)

--

rgds
LAurence

....But if I'm not who I am, who am I?

Laurence Taylor wrote in message ...
"Mark D. Zacharias" wrote:

Head cleaning problem. Video heads mainly, but the audio/control head could
cause this also. Caution is advised - improper technique can ruin the video
head. The affected head gap on the A/C head is the lower one - Sony's were a
bit notorious for this one getting dirty.
The video mute is controlled by the sync signal from the control head,
so any dirt or wear here will kill the output.

(snip)
I saw this problem a few years ago. I had an HF 100 in the bedroom,
One day I came to use it and after about half an hour the symptoms you
describe appeared. The video mute had me a bit perplexed for a while
(being a heathen who grew up with VHS, plus Beta is a bit of a rarity
round here.)
On opening up the deck, I found the cassette I was using (an old
scotch L-830) had literally fallen apart in use - shed its oxide
coating everywhere, and after cleaning the tape path and especially
the A/C head, all was well again.

My point is that it may be worth inspecting the tapes in use when this
problem occurred, considering that (here in Europe at least) they
haven't been in stores since the late 1980s and will be consequently
showing signs of age. Don't just treat the symptom (ie, dirty tape
path), go for the root cause as well!

While you're in there, take a look at the pinch roller. If you are at
the end of a tape and try to do picture search rewind and it crumples,
you'll need to give the roller a good clean - I tried ammonia I think,
seemed OK, you copuld try alcohol, some don't recommend alcohol but I
personally haven't seen it damage any rubber provide it's used
sparingly and excess is dabbed up.

(Anybody reading this with good or bad experiences with using alcohol
in this manner could perhaps enlighten me?)

good luck
Ben

Alcohol is ok, but I find naptha (lighter fluid) to be a much more effective
cleaner. You use it sparingly, and don't get it on any plastics, some don't
like it too much. The old beta tapes are probably the biggest problem,
finding new(er) ones would be a good idea. When the tape coating binders
start breaking down and the oxide sheds, the end is near. Transfer your
treasured video from the old ones and pitch them in the trash.
Regards,
Tom

you copuld try alcohol, some don't recommend alcohol but I
personally haven't seen it damage any rubber provide it's used
sparingly and excess is dabbed up.

(Anybody reading this with good or bad experiences with using alcohol
in this manner could perhaps enlighten me?)

good luck
Ben

pitch them in the trash.

Just thought I'd mention that you can reload Betamax shells with tape from
VHS cassettes. You would need to place the Beta reel into the VHS shell
for the actual winding using a VHS deck. Of course you retain the
metalized Beta leaders so the autostop functions properly. The splice can
be simply Scotch tape or whatever works...neatly trimed on the edges. The
splice won't contact anything important but don't let it ooze adhesive onto
the next turn of tape which will. Standard T120 type tape has the
thickness of Beta L500 tape so you'll end up with a tape of that length or
a bit longer.