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.

First Movie

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 painted lettering.

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 would have been no mystery.

If you need to repair a 3100R Video Capsule, you can buy the Sams Photofact online (Set 1466, Folder 1).

Here are a couple of photos of my Video Capsule in action.

It's a neat little TV, with surprisingly good audio. Combining a nice FM radio with television, it makes a dandy workshop set.

©1995-2023 Philip I. Nelson, all rights reserved