Cameras, camcorders and decks can have all sorts of
failures or intermittent problems with power connections and
distribution of power within the unit. Trouble shooting in the field
will often lead to a possible solution to get you through a shoot.
Is the unit totally dead? Check the unit's circuit
breaker or removable fuse if you can find one. Fuses can fail at any
time just from internal metal fatigue. It always helps to keep spares.
Try another battery. If your batteries don’t work, try powering up
through the 4 pin XLR input with an AC supply. Batteries have internal
fuses or circuit breakers that can also fail.
We recently had a client who was battling an
intermittent power problem when his camcorder died under battery power.
He was able to power up the camera though the 4-pin cable and was able
to finish the shoot with a battery to XLR power cord used for powering a
color monitor with a camera battery.
Don’t always assume the camcorder is at fault. We
have seen cases where batteries were so weak that cameras would not
power up. The problem turned out to be a failed battery charger.
Another common problem has been the battery bracket
to camcorder power lead attachment screws. Over time they can loosen and
develop an intermittent connection. Remove outside screws that hold the
bracket on, then tighten power lead screws.
The main power switch can wear-out and fail after
years of service. If that is suspect, leave the switch on and power up
and down by removing and installing the battery pack instead. This can
hold you over until that switch can be replaced.
Loose internal circuit boards have also been known to
cause power problems. If you feel comfortable, open the side of the
camera opposite the deck and reseat the plug in boards. They are subject
to poor connections because of vibration, shipping or whatever. We call
this symptom, "connectoritis".
The camcorder may actually be working but only the
display is out. Check the viewfinder image and video output to see if
the camera is actually working or not. Viewfinders have also been known
to fail and not show any picture at all. On some cameras, if the
contrast control is turned down all the way, no picture will be visible,
and it looks like the camera is dead. Check your output video on an
external monitor. It’s not a bad idea to have one of those small LCD
color monitors as part of your gear for back-up and camera color
checking purposes.
While you are checking your output video for life,
disconnect your lens and viewfinder cable. These on occasion, have been
known to short out the camera’s power supply, preventing the camera from
turning on. A good cameraman doesn’t need a viewfinder to shoot anyway.
(tee-hee)
With over three decades of deck experience, I have
seen several occasions where bad tape stock has caused overload of tape
transport electronics. This overload can cause the transport power
systems to go into a power protection shut down mode. There is no deck
problem at all - it was just reacting to bad or damaged tape.
We have also seen with some cameras that have low
voltage cut-off adjustment, for some reason fail and allow the unit to
shutdown at a higher voltage of a good battery. This problem requires
maintenance service to correct. It is often a condition where the menu
driven adjustment changes by itself. Often we see problems like this
happen if a battery is allowed to run dead. The internal microcomputer
just gets stupid.
Shooting in wet conditions has also caused problems
with power. Water droplets can easily short out sensitive electronic
circuits and make the camera or deck inoperative. If you feel it could
be moisture that has entered your gear, take a hair dryer to it and
drive out the moisture. As long as saltwater has not entered your gear,
you are probably ok. When salt water gets in, the water content may be
driven out but the salt deposits stay. When just humid air hits the salt
deposits, it absorbs the moisture and shorts out again. Here,
professional help may be required to remove salt deposits and eliminate
future problems.
Internal loose screws have also been known to work
out of position and wedge themselves against an electronic circuit,
causing a short. On one common dockable, this happens all too
frequently. With the power unplugged from the unit, shake it and listen
for something floating inside. If you hear something, open the side and
try to shake it enough to remove it. This may allow you to power up and
go on with shoot. Floating debris inside of electronic gear can cause
expensive circuit board damage and should not be taken lightly.
As a follow up on our "Attack of the Killer
Capacitors" article, we have had quite a few instances where old leaky
or shorting capacitors have shorted out internal power supply outputs,
making the camera inoperable. The camera, recorder, audio or any number
of circuit failures can take your gear down. Often the problem begins
with delayed power-up. Service will be needed soon.
Unfortunately, intermittent power problems are a pain
to deal with. We dislike them because too often, gear comes in without
any signs of the reported problem. We practically stand on our heads
trying to recreate the problem. We subject them to the cold conditions
of our refrigerator, heat them up under blankets, shake them, take them
down back roads in a truck, and any number of other conditions. Of
course, we have to charge for this service, but usually for only a
fraction of the actual time spent. The biggest downside is usually with
turn around time. You just cannot rush diagnosing intermittent problems.
Most of the time, the only way to diagnose is to
start swapping boards, or whatever we suspect could be the problem. We
once had a BVW-D600 with a bouncing black pedestal. We loaned out our
BetacamSP camcorder for weeks while we tried swapping virtually every
printed circuit board from CCD block, power supply, motherboard, and
everything except the wiring harnesses. To complicate things, every time
we disturbed the camcorder by swapping a board, or taking the camcorder
on trips down that bumpy road, or just poking around inside, the problem
would go away for the day.
After swapping nearly everything, the only parts left
were the wiring harnesses, which had never been a problem in thousands
of repairs. I swapped the suspect cable assembly to another deck and
sure enough the problem followed. Now you know the rest of the story.
Since then, we have repaired over twenty BVW-D600s with the same
bouncing pedestal by just replacing the worn pins on those wiring
harnesses. It’s a long story but it shows the complexity of some pesky
intermittent problems.
We keep a database of every problem we encounter, and
add the fixes to our preventive maintenance checklist for use on the
gear that comes in. This way we can minimize future problems you may
have in the field. For example, we inspect the internal boards for
failure signs such as corroded or discolored capacitor leads. We find
that most clients will go ahead with repairs if their gear is still
making a profit. Please re-read this article on our website
www.macievideo.com/tips/killercapacitors.html. I may be writing more
on this subject soon.
As we all know "Stuff happens" but with a little
maintenance education you may be able to get through an important shoot
and save a client.
Take care,
Roger
