Panasonic VCR; a grey screen unless you pause, FF or REW???

Possible missaligned or busted heads

"reverse_side" bravely wrote to "All" (09 Feb 06 18:01:52) --- on the heady topic of "Panasonic VCR; a grey screen unless you pause, FF or = REW???"

re> Subject: Panasonic VCR; a grey screen unless you pause, FF or REW??? re> Xref: core-easynews sci.electronics.repair:357884

re> Lots of talented people on this forum, if anyone knows how to explain re> this problem I'd be very grateful.

re> It's the NV-FJ710B (Tape Library System and very speedy fast forward re> and rewind capabilities flavour of a Panasonic workhorse) - just past re> it's 5th birthday and without a peep of a problem, suddenly won't play re> tapes properly anymore.

re> Symptoms: cueing forward or backwards is fine, pausing and slow frame re> advance is crystal too, but playing just gives a pure grey screen re> with audio in the background? The tapes won't play in another VCR, re> vice versa and the usual tracking & v-lock just made me frown re> :crybaby: Pre-recorded tapes are a no-no now too.

re> Is this repairable or have I got to start looking at DVD RW / hard re> drive / combi alternatives?

It may be simply one clogged or really dirty playback head. :) OTOH that head may be chipped. :(

The typical symptom here is that the special effects heads work fine but playback is noisy or blanked.

Read the faq to learn how to clean the heads safely.

A*s*i*m*o*v

... If all else fails, hurl it across the room a few times!

Thanks nvic/asmiov; I tried a careful head clean with a small amount of meths, can u adv where the faq is for doing cleaning heads properly etc, the one on the bottom is mainly for forum admin etc.

wouldn't be surprised if there's an olympic event of VCR shot put soon!

are the chipped/misaligned symptoms visible btw?

just tested playback and it looks so close to being fine, grey then good picture, then it fights but then goes grey again (or gray as you guys may like instead!).... grrrr. 300 joules, stand clear.

"reverse_side" bravely wrote to "All" (10 Feb 06 12:01:08) --- on the heady topic of "Re: Panasonic VCR; a grey screen unless you pause, FF or REW"

re> Subject: Re: Panasonic VCR; a grey screen unless you pause, FF or REW re> Xref: core-easynews sci.electronics.repair:357963

re> Thanks nvic/asmiov; I tried a careful head clean with a small amount re> of meths, can u adv where the faq is for doing cleaning heads re> properly etc, the one on the bottom is mainly for forum admin etc.

re> wouldn't be surprised if there's an olympic event of VCR shot put re> soon!

re> are the chipped/misaligned symptoms visible btw?

re> just tested playback and it looks so close to being fine, grey then re> good picture, then it fights but then goes grey again (or gray as you re> guys may like instead!).... grrrr. 300 joules, stand clear.

The faq has a new address so you should search for it. There was a change of ip server so the address seen around might not be right.

A small 30x lens and bright light is needed to inspect the head chips for damage. An effects head looks different from a play head (gaps). The head gap looks like the points of the z here: ==z== Tiny wire coils can be seen behind the pole pieces that protrude. The gap is wide or narrow depending if it is an effects or play head. A chipped head will have half a corner missing: ==... or ...== Or worse: ..... just jagged edges or completely broken off.

As for cleaning the heads, the most important warning is to never scrub up and down. The next most important warning is not to use anything that can get snagged, for instance cotton swab is a no, no. There are special chamis swabs made for vcr head cleaning.

A simple method I use is with the machine unplugged. Take a 5cm (2") long strip of printer paper 1cm (3/8") wide dipped in isopropyl 99%. Place the strip along the tape path edge over the bottom drum and shuttle the top drum back and forth so that the head scrubs against the strip of paper. Apply only gentle pressure with the fingertips. Turn the strip over or use a new strip until it no longer streaks with dirt. Do this for each head in turn. It seems crude but is quite safe. Let the alcohol dry off before use.

A*s*i*m*o*v

reverse_side ha escrito:

if the picture is cycling off and on or good and bad, replace the pinch roller. This is probably skewing the tape up and down on the AC head. Watch its behaviour with the top off and see if the tape gets slightly wrinkled at any stage of the tape path.

-B.