Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
gothika
 
Posts: n/a
Default Remove Hard Deposits on Video Heads?

On Sun, 25 Jan 2004 00:01:52 GMT, (Michael) wrote:
Try using a stronger solvent. I use a cotton swab and a good brand of
carb cleaner(aerosol).
You can also use a contact cleanerlike CRC QD Electronic cleaner.
If you use carb cleaner use a clear type. I use the Wal-mart store
brand (SuperTEch) or the autozone stor brand(it comes in a yellow and
red spray can.)
Triple trico will work as well, or even butane lighter fluid.
Bear in mind that all these stronger solvents can damage plastic, so
use caution and don't oversaturate the swab.
Some disassembly will be required to get clear access to the
head.(Most of the time just removing the tape hatch cover will
suffice.)
spray the swab with the solvent and shake it a time or two to get the
"drips" out then quickly rub the drum head with it.
It'll take several swabs to remove all the deposits.
Once I get the hard muck off I follow up with a foam swab with head
cleaner or denatured alchohol to remove any lint or chemical residue
from the swabs.


Hi. I have a Panasonic PV-DV400D MiniDV camcorder that has gotten hard
deposits on the video heads, resulting in one head's not being able to
read. There's still enough tape contact for record, and recordings made on
this camera play in other cameras.

Microscopic examination shows obvious hard deposits across the head gaps,
but nothing I've tried will remove them. Is there any way to do it? If
not, is there some cheap source of a head drum (such as a wrecked unit)
for this camera?

Any help is appreciated.

Thanks!

Michael


  #3   Report Post  
MarkC
 
Posts: n/a
Default Remove Hard Deposits on Video Heads?

Have you tried Acetone? Also try calling or emailing Panasonic's
tech-help line to see what they recommend. You could see if there are
comparable parts units on Ebay.




  #5   Report Post  
Steve(JazzHunter)
 
Posts: n/a
Default Remove Hard Deposits on Video Heads?

On Tue, 27 Jan 2004 04:03:35 -0500, "Steve(JazzHunter)"
wrote:

On Tue, 27 Jan 2004 01:13:25 GMT, (Michael) wrote:

In article , gothika
wrote:

On Sun, 25 Jan 2004 00:01:52 GMT,
(Michael) wrote:
Try using a stronger solvent. I use a cotton swab and a good brand of
carb cleaner(aerosol)...


I've tried most of those solvents and they don't take it off. I'm an
ex-VCR tech, and yes, I do know how to open the machine and clean the
heads! I've never seen anything like these deposits. I suspect they were
caused by the famous Panasonic wet lubricant incompatibility problem.


For the most stubborn head deposits I use Perchloroethylene, also
known as tetrachloroethylene, ethylene tetrachloride, or PERC. It
comes in a bottle labeled "Spot Remover." It is harmless to heads,
and evaporates instantly, but is lethal to plastics! There has never
been a situation where it has not removed the problem, unlike gasoline
and alcohol-based solvents.


I should mention it also makes chamois stucky. Put a drop of Perc on
a bit of lint-free paper and by hand turn the heads against it. For
the worst cases moisten a Q-tip to apply to the head, then wipe with
paper. Since it dissolves plastic and petroleum materials, it will
remove lubricants and tape binder from the head, which is what we want
to accomplish. It doesn't attack carbon or metals, or shellac (except
by extended soaking)

. Steve .

. Steve ..

Strong solvents don't seem to do the trick. I've tried naptha (cig lighter
fluid, which I presume is what you meant by "butane lighter fluid," since
actual butane is a gas), petroleum-based contact cleaner, alcohol, you
name it. I haven't actually tried carb cleaner, but I think it's very
similar in composition to the petro-based contact cleaner I have. I guess
I can go get some actual carb cleaner and try that.

Any other ideas?

Thanks.

Michael




  #6   Report Post  
gothika
 
Posts: n/a
Default Remove Hard Deposits on Video Heads?

On Tue, 27 Jan 2004 01:13:25 GMT, (Michael) wrote:
Actually I meant butanol.
The carb spray I use has acetone and some other petroleum based
solvents.
Most of the hard black deposits you find on tape drums are from the
tapes themselves. The lubricants used on the moving parts is usually
lithium based or silicone based and will clean off very easy.(The
reason it'd be black is from dirt/dust and tape "shavings" that fall
down onto the tape guide runners.
This kind of deposit will clean off easily if it gets on the drum,
owing to it's base constituent being grease, which most solvents will
clean off very easily.
The hard to get off stuff is always tape coatings.
The binders and adhesives used inthe oxide coatings can be as tough as
cement and severe build up can necessitate drum removal and soaking.
I just keep at it with the swabs and carb spray until it starts to
flake off. It can take alot of time and effort but I've always been
able to get all mine ungummed this way.
If you do it by the book, pulling the drum and soaking it in acetone
or triple trico is the recommended procedure.

In article , gothika
wrote:

On Sun, 25 Jan 2004 00:01:52 GMT,
(Michael) wrote:
Try using a stronger solvent. I use a cotton swab and a good brand of
carb cleaner(aerosol)...


I've tried most of those solvents and they don't take it off. I'm an
ex-VCR tech, and yes, I do know how to open the machine and clean the
heads! I've never seen anything like these deposits. I suspect they were
caused by the famous Panasonic wet lubricant incompatibility problem.

Strong solvents don't seem to do the trick. I've tried naptha (cig lighter
fluid, which I presume is what you meant by "butane lighter fluid," since
actual butane is a gas), petroleum-based contact cleaner, alcohol, you
name it. I haven't actually tried carb cleaner, but I think it's very
similar in composition to the petro-based contact cleaner I have. I guess
I can go get some actual carb cleaner and try that.

Any other ideas?

Thanks.

Michael


  #7   Report Post  
Michael
 
Posts: n/a
Default Remove Hard Deposits on Video Heads?

Thanks for all the advice! I'll try PERC. That sounds like the next
natural step.

Michael
  #8   Report Post  
Michael
 
Posts: n/a
Default Remove Hard Deposits on Video Heads?

Forgot to mention... yes, it's definitely from tape coatings. When I
mentioned wet lube, I meant the famous miniDV problem with Panasonic
tapes. They use a wet lubricant, as opposed to every other brand's dry
lubricant, on their tapes, and mixing Panasonic tapes with those of other
brands in the same camcorder can lead to this ultra-tough deposit glaze.
This was widely written about in the early days of miniDV. It may be that
Panasonic has fixed this incompatibility, but I suspect this camcorder's
problem was caused by it, especially since it's a Panasonic cam, it's a
few years old, and it probably came with one of the offending Pana tapes.

Michael
  #10   Report Post  
Michael
 
Posts: n/a
Default Remove Hard Deposits on Video Heads?

I have some Gonzo Stain Remover, but I can't find any reference to what's
in it. Is this the right stuff (PERC or something similar that would
work)?

Michael


  #13   Report Post  
tweak
 
Posts: n/a
Default Remove Hard Deposits on Video Heads?

On 31 Jan 2004 03:44:42 -0800, (Andre) wrote:

"Steve(JazzHunter)" wrote in message . ..
On Wed, 28 Jan 2004 21:11:20 GMT,
(Michael) wrote:

I have some Gonzo Stain Remover, but I can't find any reference to what's
in it. Is this the right stuff (PERC or something similar that would
work)?

Michael



That doesn't ring a bell. The smell of Perc is pretty unmistakable.
One clue is that it would melt plasitc if applied. But if it's not
identified I wouldn't use it on a video head.


Yeah, you might end up with a nice clean video head chip which is no
longer attached!

The "microscope and very fine screwdriver" trick apparently works in
really stubborn cases, found that in one of the "VCR Repair
Illustrated" books.
Best used only as a last resort when you've tried everything else.


. Steve .



Didn't want to mention it either as using any hard tool against a
video head is very risky.
That said I have a right angle dental pick that I use in the most
dificult cases.
soak the large clump with plenty of solvent then using my 40x scope
and the pick very carefully apply pressure againdt the center of the
clump.(Nevery try to edge scrape, it'll ALWAYS scratch the drum head.)
Push very gently downward and laterally along the drum surface away
from the center of the drum towards the edge.
The clump should slide off if the solvent has soaked into the base of
the clump enough to soften it.
Like the man said this is a last resort.
If you have the tools to pull the drum and an ultrasonic cleaner
that's the best possible solution.
Run it overnight in an ultrasonic bath and that will clean it all off.
  #14   Report Post  
Hubert Littau
 
Posts: n/a
Default Remove Hard Deposits on Video Heads?

Before the chemists and M.E.s among us get too carried away, put a
brand new tape in it, press play and take a 2 hr. walk You might be
surprised by the result. Ditch the new tape and enjoy.

On Sat, 31 Jan 2004 13:00:37 -0600, tweak
wrote:

On 31 Jan 2004 03:44:42 -0800, (Andre) wrote:

"Steve(JazzHunter)" wrote in message . ..
On Wed, 28 Jan 2004 21:11:20 GMT,
(Michael) wrote:

I have some Gonzo Stain Remover, but I can't find any reference to what's
in it. Is this the right stuff (PERC or something similar that would
work)?

Michael


That doesn't ring a bell. The smell of Perc is pretty unmistakable.
One clue is that it would melt plasitc if applied. But if it's not
identified I wouldn't use it on a video head.


Yeah, you might end up with a nice clean video head chip which is no
longer attached!

The "microscope and very fine screwdriver" trick apparently works in
really stubborn cases, found that in one of the "VCR Repair
Illustrated" books.
Best used only as a last resort when you've tried everything else.


. Steve .



Didn't want to mention it either as using any hard tool against a
video head is very risky.
That said I have a right angle dental pick that I use in the most
dificult cases.
soak the large clump with plenty of solvent then using my 40x scope
and the pick very carefully apply pressure againdt the center of the
clump.(Nevery try to edge scrape, it'll ALWAYS scratch the drum head.)
Push very gently downward and laterally along the drum surface away
from the center of the drum towards the edge.
The clump should slide off if the solvent has soaked into the base of
the clump enough to soften it.
Like the man said this is a last resort.
If you have the tools to pull the drum and an ultrasonic cleaner
that's the best possible solution.
Run it overnight in an ultrasonic bath and that will clean it all off.


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
NTSC-compatible video signal circuit - ntsc.pdf (0/1) Rico Rivera Electronics 1 April 13th 04 06:57 PM
Replace vcr video head William Sangismoch Electronics Repair 10 October 1st 03 05:05 PM
A Video for Beginners (a bit long) Fred Holder Woodturning 1 September 30th 03 09:37 PM
HELP tuning video belmont5 UK diy 8 September 28th 03 06:56 PM
Sony Model KV-32XBR48 slow turn on and flashing video for short period at turn on Ron Novini Electronics Repair 4 September 20th 03 12:10 AM


All times are GMT +1. The time now is 08:06 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"