JVC 3100R Video Capsule Television/Radio (1978)
If you don't recognize this JVC Video Capsule TV, you're just not
paying attention! One of the most memorable TV designs ever, this
1978 creation is a favorite of "space-abilia" collectors as
well as television hounds.
The model 3100R Video Capsule is the perfect companion for my model
3241 VideoSphere. The following photos show them together.
In the second shot, they are using their built-in antennas to play a movie
broadcast from my home transmitter.
The VideoSphere and Video Capsule are pretty similar in performance. Both
receive UHF and VHF and can use an external antenna or built-in rod antenna.
The VideoSphere has a larger picture tube and a clock/timer in its base.
The Video Capsule has an AM/FM radio, which can be played when the TV screen
is lowered to its closed position.
Finding a Video Capsule
I've been trying to thin out collections lately, but when I saw this
Video Capsule for $30 in the local craigslist, I couldn't resist.
Lifting the pyramid-shaped top reveals the screen, which is held above the
base for a futuristic, Predicta-like look. These photos show the TV on the
day when I brought it home, before doing any cleanup or diagnosis.
The owner made no claims about it working, but when I got it home, the
radio played beautifully. No such luck with the television. When I switched
the mode control from Radio to TV, the screen flashed a momentary bright blip and
then the set went completely dead. No video, no audio, nada.
Oh well, at least it was cheap! "Perhaps it's something simple in the power supply,"
I told myself, as I began to disassemble the TV for diagnostics.
Disassembly and Initial Diagnostics
As with any pedestal-style
television, taking it apart is a multi-step process. First, you
remove the case from the upper unit. The speaker is mounted in the case;
be careful not to rip off its leads.
Removing the upper case provides access to the CRT and the small
video/horizontal board. At this time, I also removed the cover from
the base unit. You can flip up the upper unit while still connected, but you'll need
to support it, since the upper arm's spring is too weak
to hold it without the balancing weight of the upper case.
You can operate the 3100R in this state if you connect the
speaker via clip leads. Before applying power, I wanted to do some basic
component checks on the video/horizontal board. For this, I used my EDS 88A ESR tester, an
invaluable tool for working on solid state electronics. Solid state devices
tend to have many more electrolytics than older gear, and the 88A can
test them while still connected in circuit.
All of the electrolytics looked fine, except for one in the in the contrast control circuit
that was slightly questionable. I noted the part number but I didn't replace it. Although a
bad cap in that spot would affect video output, that wouldn't make the whole set go dead. If there's a smoking
gun, we'll have to find it elsewhere.
The next disassembly step is to remove the upper unit's arm cover. The following photo
shows the cover lying next to the TV's base.
Notice, too, that I have unplugged two
long, thin white connectors near the picture tube's base. These connect everything
between the upper and lower units. Mark one of them with a pen or a tag of
tape so that you don't mix up these identical connectors during reassembly.
Removing four screws from the arm lets you take off the upper unit. I temporarily
unplugged the CRT socket to ease those big white connectors out
of the cable snarl.
It takes some flexing and wiggling to slip off the lower case escutcheon.
In addition to removing knobs, you'll need to unscrew the rod antenna
mount. This lets you tilt the antenna enough to slide off the escutcheon
in that direction.
At this stage, I decided to do some voltage checks under power. The main
boards in the base unit are largely inaccessible, but at least I can measure voltages
in the upper unit, as well as some key points (at fuse connections, etc.)
down below. In this photo I have propped the upper unit with a piece
of stiff foam, plugged the big connectors in, and connected the
speaker with clip leads. It's a rather precarious setup, but I'm only
going to make some quick tests.
To my surprise, when I powered up the TV this time, I saw a flash of light on
the CRT that lasted a couple of seconds. What's going on here? I powered
down and then turned on the TV again. This time, the screen lit up and stayed
lit. I could also hear some static from the speaker.
Could it really be this easy? I powered down, loaded a test pattern DVD into
the player, and then tried again. Bingo!
It's a little odd for a dead TV to spring back to life like that. On the
other hand, this set does have a Radio/TV mode switch. If that had become
funky from disuse, perhaps moving it a few times dislodged
enough gunk to allow normal operation.
The other controls—Volume, Contrast, and so on—certainly
needed cleaning. The Volume slider scratched like crazy when moving it,
and Contrast blipped all over the place, from extreme contrast to almost
none, when moved even slightly. I cleaned all of them thoroughly with DeOxit.
Here's the television playing a movie at this stage. The audio and video
are fine and all controls operate smoothly.
Cleanup and Reassembly
Before reassembling the TV, I cleaned and polished the cabinet parts. The
white plastic is rather soft and it easily picks up scratches or
scuff marks. One side of the cabinet was also yellowed
from exposure to the Sun's ultraviolet rays.
I used Novus Plastic Polish #3 to deal with the scuffs and yellowing,
following it up with #2 polish to restore the shine. If you use polish
or fine sandpaper on this cabinet, be careful not to scrub off the black
When reassembling the cabinet, I noticed a problem with the TV's failsafe
switch. When you lower the screen, the switch turns off the TV to prevent
overheating when not in use. The switch is circled in the following photo.
When the TV is assembled, only the little black tip protrudes through a hole
in the base cover—easy to overlook unless you know it's there.
When the base was back on, the failsafe switch rubbed slightly against the
cover, occasionally sticking in the power-off position. This solved the
mystery of the dead TV. Had I known about the switch beforehand,
there wouldn't have been a mystery at all.
Here are a couple of photos of the Video Capsule in action.
It's a neat little TV, with surprisingly good audio. Combining a nice
FM radio with television, it just became my new favorite workshop set.