JVC HR-C3 VHS-C repair

[Studio263]

I've wanted to have a go at a JVC HR-C3 VHS-C portable for some time, they are a beautifully made and unusually well styled machine. This was JVC's first VHS-C model, they were announced in 1982 and appeared in the UK during the following year. Television magazine mentioned the UK launch of the HR-C3 in its April 1983 issue. To put this into context, the HR-7200EK (= Videostar 3V29) was still in the JVC catalogue alongside the HR-C3, even though they look several generations apart.

The HR-C3 is very much a first generation VHS-C recorder and so it has a full-sized drum - the 3/4 sized ones with four sequenced heads and a 270 Deg. wrap came later. It is still tiny though - about 19cm square and less than 2kg in weight.

As bought my HR-C3 was sold as having a jammed cassette door, although some of the LEDs on the front panel were lit. Taking the machine apart is tricky when its like this as you need to be able to open the lid to remove it, and you need to be able to do that to get the top off. I worked around it by removing the front panel and the microprocessor PCB behind it, this made it possible to tweak the mechanism just enough to pop the lid up.

Removing all the PCBs from the deck allowed the mechanics to be inspected. To save power this model uses a latching solenoid with a permanent magnet inside to select some of the deck functions, including locking the cassette lid when the tape is playing. This was still engaged but it popped out easily enough, now the lid opened normally. However, once the power was applied the solenoid locked again so I was back to where I started.

Apart from this little else worked. The LCD tape counter buttons did what they were supposed to and the power indicator was on but none of the other controls did anything. Winding the mechanism through all its modes by manually turning the loading motor didn't change anything either. One problem with working on machines like this is that everything is very small and it is difficult to make measurements unless you have an extension lead set (which I don't). Therefore repairs have to be done by guesswork, dismantling everything to replace the suspect part, re-assembly and test. I thought that the symptoms looked like the microprocessor stuck in reset. It lives on the back of the front panel PCB and is inaccessible, however you can see C7 (4.7uF/25V) and this sets the reset pulse length. Looking at the circuit diagram the voltage here should get to just over 2.6V to clear the reset but in my case it got stuck at 1.6V. C7 was leaky, a replacement cleared the reset fault.

The machine would now switch on and the solenoid unlatched, the next problem was that it would only stay on for about a second before switching off again. I suspected the dew sensor but the light wasn't on - probably not that then. Persistence and repeated pressing of the power button made the machine stay on for longer and longer periods until eventually it stayed on permanently. The tape then laced up and played but the next time I tried it it went back to turning itself off again. There was clearly nothing serious wrong so what does that leave? The low battery function prevents the tape being left threaded up if the battery runs out and stops the battery from being too deeply discharged by switching everything off if the voltage falls to far and sure enough C3 (22uF/16V, also on the front panel PCB) only had just over 2V across it when 4V is the correct figure. This is where the battery voltage is sampled; IC3 is a dual comparator which then gives two levels of warning as the battery is used up. Replacing C3 cured this one.

A tape could now be played, the picture was in colour and there was good sound. The only thing that spoiled it was a noise bar running through it, clearly the capstan servo wasn't locked. The control head wasn't dirty and the pinch roller wasn't worn either so it was something more serious that had to be amiss. Bearing in mind the previous problems and that servo circuit is all underneath and you can't see most of it I looked for small electrolytics of same type as the previous faulty ones. C7 on the servo panel (47uF / 6.3V, not to be confused with C7 on the front panel) was the right colour, looked a bit corroded underneath and hissed and smelt of fish as it was being unsoldered. As a pattern was clearly emerging I had a look on the other PCBs and found two more suspect looking 10uF capacitors on the Y/C panel which measured OK but still hissed when they were removed. Most of the others were of a different type which appeared to be more durable.

That was the last of the faults cleared. Portables don't get used as much as full-sized machines (this clearly hasn't done a decade of time-shifting Corrie...) but they do get pushed to the back of wardrobes and forgotten about - this one probably worked when it was put away.

Now all I have to find are all the accessories, of which there are many. So far I have the carrying bag, strap, pouch for a spare battery, battery, battery charger, AC adaptor, car battery adaptor and remote control unit. that just leaves the camera (GZ-S3E) and monitor (TM-P3E) to find, and of course the SF-P3U 'shoulder frame' which turns the whole system into a giant camcorder - they can't have sold many of those!

In the pictures I've shown the HR-C3 with its rival from Sony, the EV-C8. These are quite a bit later (1985) and are one of the original Video 8 models. Despite the narrower tape, the greater availability of miniature components and Sony's magic ability to make a tiny version of anything it isn't really that much smaller. I think this shows what an incredible piece of work the JVC HR-C3 was.

[Jonster]

Nice recorders, the bees knees back in the day. I have a couple of the cameras here, along with a selection of tapes and a couple of the hard carrying cases plus all the interconnecting cables here, message me if you are interested.