Prev: magnavox plays only background noises
Next: Antenna interaction question
From: powerampfreak on 24 Jan 2010 13:45
Hi all.
I was helping a friend replacing his video drum on a Panasonic NV-HV61
vhs player.
This because it hardly played tapes in SP mode (picture full of white
sparks) but EP recording went fine. He bought a replacement drum
(entire unit, upper drum and lower part of it). This was a simple
task, just 3 screws, place the new drum and the mechanics back.
Now it plays SP just fine (except for it takes about 10-15 seconds
before the picture comes, which is probably not right) but LP and EP
tapes won't give any picture.
My question is: Is there something that might need to be adjusted
when fitting a new drum?
Why will it take so long (10-15) seconds to get a picture in SP mode,
but when it comes the picture is great, and wil last until you stop
the tape.

Thanks a lot for any advice.
Best regards
PAF
From: circuit on 26 Jan 2010 00:29
Yea, the guide posts will need to be readjusted...and its a good idea to
clean all the tape paths and the pinch roller and the capstan it presses
against. The guide posts alignment is best done with an oscilliscope,
because if its not done precisely, it may not be able to play tapes recorded
on other machines.

The guide posts are what moves up and wrap the tape around the head.

http://www.youtube.com/watch?v=Mo_dA-k5bIw


VCR alignment kit:

http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=180448638876






"powerampfreak" <powerampfreak(a)hotmail.com> wrote in message
news:abcd9ec8-69c5-463f-a100-ccf5fb390966(a)22g2000yqr.googlegroups.com...
> Hi all.
> I was helping a friend replacing his video drum on a Panasonic NV-HV61
> vhs player.
> This because it hardly played tapes in SP mode (picture full of white
> sparks) but EP recording went fine. He bought a replacement drum
> (entire unit, upper drum and lower part of it). This was a simple
> task, just 3 screws, place the new drum and the mechanics back.
> Now it plays SP just fine (except for it takes about 10-15 seconds
> before the picture comes, which is probably not right) but LP and EP
> tapes won't give any picture.
> My question is: Is there something that might need to be adjusted
> when fitting a new drum?
> Why will it take so long (10-15) seconds to get a picture in SP mode,
> but when it comes the picture is great, and wil last until you stop
> the tape.
>
> Thanks a lot for any advice.
> Best regards
> PAF

From: powerampfreak on 26 Jan 2010 15:58
On 26 Jan, 06:29, "circuit" <circ...(a)123456.tv> wrote:
> Yea, the guide posts will need to be readjusted...and its a good idea to
> clean all the tape paths and the pinch roller and the capstan it presses
> against. The guide posts alignment is best done with an oscilliscope,
> because if its not done precisely, it may not be able to play tapes recorded
> on other machines.
>
> The guide posts are what moves up and wrap the tape around the head.
>
> http://www.youtube.com/watch?v=Mo_dA-k5bIw
>
> VCR alignment kit:
>
> http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=180448638876
>
> "powerampfreak" <powerampfr...(a)hotmail.com> wrote in message
>
> news:abcd9ec8-69c5-463f-a100-ccf5fb390966(a)22g2000yqr.googlegroups.com...
>
> > Hi all.
> > I was helping a friend replacing his video drum on a Panasonic NV-HV61
> > vhs player.
> > This because it hardly played tapes in SP mode (picture full of white
> > sparks) but EP recording went fine. He bought a replacement drum
> > (entire unit, upper drum and lower part of it). This was a simple
> > task, just 3 screws, place the new drum and the mechanics back.
> > Now it plays SP just fine (except for it takes about 10-15 seconds
> > before the picture comes, which is probably not right) but LP and EP
> > tapes won't give any picture.
> > My question is:  Is there something that might need to be adjusted
> > when fitting a new drum?
> > Why will it take so long (10-15) seconds to get a picture in SP mode,
> > but when it comes the picture is great, and wil last until you stop
> > the tape.
>
> > Thanks a lot for any advice.
> > Best regards
> > PAF

Thanks for the reply. So, the guides are the only necessary
adjustment, then..
As I said, SP tapes plays just fine (after 15 seconds), but I realize
the LP and EP demands more of the machine.
I've access to an oscilloscope, where do I hook it up?
If you don't mind you could post my e-mail if you like!
Thanks a lot!

Regards, PAF
From: Wild_Bill on 27 Jan 2010 08:42
There is a head amplifier module associated with the head(s) signals. The
alignment procedures info is included in the service manual for that
particular model.

A 'scope is required for both mechanical and signal alignment, and you'll
need to know the correct test points and service adjustment steps, all
included in the service manual.

I think you need an alignment test tape for the procedure, but it's been a
long time since I've done the alignment procedures.

Playing random tapes isn't a particularly revealing test. You'll want to try
to accomplish very good results with FF, Rew and freeze in Play mode, and
also recorded material compatibility with other machines.

--
Cheers,
WB
..............


"powerampfreak" <powerampfreak(a)hotmail.com> wrote in message
news:abcd9ec8-69c5-463f-a100-ccf5fb390966(a)22g2000yqr.googlegroups.com...
> Hi all.
> I was helping a friend replacing his video drum on a Panasonic NV-HV61
> vhs player.
> This because it hardly played tapes in SP mode (picture full of white
> sparks) but EP recording went fine. He bought a replacement drum
> (entire unit, upper drum and lower part of it). This was a simple
> task, just 3 screws, place the new drum and the mechanics back.
> Now it plays SP just fine (except for it takes about 10-15 seconds
> before the picture comes, which is probably not right) but LP and EP
> tapes won't give any picture.
> My question is: Is there something that might need to be adjusted
> when fitting a new drum?
> Why will it take so long (10-15) seconds to get a picture in SP mode,
> but when it comes the picture is great, and wil last until you stop
> the tape.
>
> Thanks a lot for any advice.
> Best regards
> PAF

From: amdx on 27 Jan 2010 11:15

"circuit" <circuit(a)123456.tv> wrote in message
news:hjluko$1dh$1(a)speranza.aioe.org...
> Yea, the guide posts will need to be readjusted...and its a good idea to
> clean all the tape paths and the pinch roller and the capstan it presses
> against. The guide posts alignment is best done with an oscilliscope,
> because if its not done precisely, it may not be able to play tapes
> >recorded on other machines.

I would be a little slow to start adjusting the guide posts, in my
experience*
(I admit it's been 15 yrs) I very rarely had to adjust the guides after a
video
head replacement, they are/were made very precise. Make sure the head drum
seated properly when you installed it.
Mike
*I replaced over 100 head assy's in my 11,000 vcr repairs.
I got out when the price of vcr's got down to about $200.


 |  Next  |  Last
Pages: 1 2
Prev: magnavox plays only background noises
Next: Antenna interaction question