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Attack of the Killer Capacitors
Since finishing up the audio problem
series, we at Macie Video Service have increased our technical staff, finished our
shop expansion with the addition of a second camera set-up station, and
are in the middle of a better organization of our parts inventory. We
are now gearing up for servicing digital recording camcorders and decks.
As many of you probably know, we have not had the time to devote to any
format other than Betacam. We are beginning to see increased demand for
servicing digital recording camcorders from our own client base, but
more of that in an upcoming newsletter. Now I will cover an important
issue that has a major effect on long term operation of almost all video
gear.
In a previous newsletter entitled "Forever Young", I
wrote about several issues concerning proper care and maintenance of
your cameras, camcorders and decks. One of them was about a problem we
have seen more and more in recent years, failure of surface mounted
electrolytic capacitors.
Capacitors are components used in electronic circuits for coupling of
signals, filtering of power, timing of signals, etc. They are
constructed with metal foil, separated with an insulator soaked with an
electrolyte solution, and encased in an aluminum shell. These components
are not subject to wear such as heads and pinch rollers, but instead
deteriorate from heat and age.
With video gear being around for decades,
why has this become such a big problem? The answer lies in its
miniaturization. It started in the late 80s with the development of
camcorders, where both camera and VTR had to be shrunk into a case the
size of just a camera. Nearly every component - heads, integrated
circuits, resistors and capacitors - all have shrunk in size. These
smaller caps have
smaller and thinner housings, wire leads, insulation, and seals to keep
electrolyte fluids captive. The results are earlier internal failures
and greater chance of this corrosive fluid leaking out and damaging the
PCBs (printed circuit boards). Life span of caps in prior gear was rated
in excess of ten thousand hours, compared to newer ones rated in the low
thousands of hours. Problems can be as numerous as you can imagine,
considering that almost every circuit uses these caps. The cost of
repair varies with trouble-shooting time and extent of physical damage
caused if the cap leaks badly. Often it is too late to cost-effectively
repair the PCB, so it must be replaced.
This capacitor is good. Note shiny finish where cap
is soldered to board. This eventually turns dark gray just before
leaking. |
This capacitor has leaked electolyte onto the PCB.
Note the blackened area on the PCB. |
This shows the damage to board under the capacitor. |
To repair the board, the corrosion must be scraped
off and cleaned. |
What, you ask, are we doing about this problem? First
we are trying to let you know what to expect in terms of maintenance
problems for you gear. As for our servicing, we are on the lookout for
tell-tail signs of failures of these components, by making visual
inspections of all caps as gear begins to age, and checking for audio /
video record and playback problems. As it turns out it is more labor
cost effective to replace a PCB board full of caps than to trouble-shoot
just the bad ones, because with proper soldering equipment we can
replace each one in just 4 minutes. With just an hours labor we can
replace quite a few caps, which gives that PCB a new lease on life. By
the way a typical broadcast camcorder uses about 100 of these caps, a
popular field deck uses about 300.
Our ongoing preventative maintenance of camcorders
involves a systematic refurbishment of the PCBs as we discover problems
developing, usually when the gear is 6 to 8 years old. We continue this
over a period of several service check-ups until all the PCBs are done.
This maximizes reliability and spreads out maintenance costs. A total
camcorder recap costs about a third less than an upper drum replacement
and should last another six to eight years. What can you do about this
problem? Retire or sell gear before it hits 6 years old. Repair each
problem as it happens, which will nickel and dime you to death and
probably hurt your client relationship. Consider preventive maintenance
and begin a refurbishing program, which will spread costs and improve
reliability.
Unfortunately it's not just broadcast camcorders that
have this problem but virtually all video gear from broadcast to
consumer, from cameras to decks, and from manufacturer to manufacturer.
Did I hear anyone say disposable gear? On a personal note, my own
8-year-old consumer camcorder failed to operate recently. I recapped it
without any trouble-shooting and it came back to life, hopefully for
another 8 years. That's the good part of being handy at fixing gear.
How do you know if your video equipment has these
trouble-making caps? Remove a cover and look inside for ones similar to
the above pictures. Prepare yourself for the inevitable. Create a plan
for either maintenance or replacement.
By the way, because of our Internet exposure we get many e-mail
inquiries about service from around the globe and too often we are asked
about not only broadcast equipment but also consumer camcorders as well.
Our primary service is with broadcast television field cameras,
camcorders and decks. We serve in excess of a thousand broadcast
freelancers, government agencies, sport networks, rental companies,
production companies, and manufacturers.
We have been supporting Ikegami for over ten years
with their HL-V55 and HL-V59 camcorders. Our secondary focus has been
with maintenance of PVW and UVW studio decks and Sony's eight-inch field
monitors, which seem to be the standard field monitor these days. As you
all know we also specialize in professional camera set-ups on most
cameras and camcorders, from DVCAM, BetacamSP, BetaSX, Digibeta,and even
DVCPRO.
Take care,
Roger |
