Panasonic NV-9600 will not eject?
 

Howdy,

I have a Panasonic NV-9600 3/4" U-Matic deck that won't eject. Got it on ebay for 350. All lights come on, keys work, etc. Bought the weird power cord, and tried to get a tape in. Come to find that the eject key just flashes and makes a whining sound.

I've made a YouTube video demonstrating the problem.

https://youtu.be/S0X8WNWSs6M

Also, looking from the back of the VCR, is the right pin on a three-prong oval connector usually the hot wire? How would I be able to tell if the polarity was wrong? I have determined that the right plug on my female oval connector, again, with the plug facing the VCR, is the hot one.

I have to ask all this because even through all the service manuals for these panasonic u-vision machines, I cannot find any indication of which of the wires is hot and cold. I think the machine might not be ejecting because the polarity could possibly be wrong. I read that HP, way back in the 60/70's had some variation in the polarity of their power cables.

It's certainly at the right voltage though, 120. Checked it with a multi-meter from both the AC socket itself, and from the power cord. It's also dialed in correctly on the VCR's adjustable voltage switch. I marked the power cord correctly with red sharpie just in case I forgot. I still, however, cannot determine if it's the correct polarity for the VTR itself.

Also, do these VCR's use more than 7 amps? Is it OK to use a cable marked at 125v, as shown in the video, with a 120v outlet? Will the VTR not function properly since it's so close to voltage limit of the power cord?

Thanks!

You just have to read through the service manual, Though a service manual is not a troubleshooting guide, It is a measurement and testing manual with parts breakdown and schematics, you would have to know how to diagnose a problem from a given symptom and go through the troubleshooting steps.

Would you happen to know what would cause something like that to happen?

Hundreds of things, the only way to find out is to examine the parts and look for anything unusual.

Don't worry about the voltage rating of the cable in this instance. Without wandering too far in to electrical theory, cable voltage ratings are quite nominal and generally refer to the insulative properties rather than conductive properties. I would be inclined to imagine that if this cable was sold in a 230VAC region it would be stamped 230VAC - it's just a differentiation between using it for domestic and HV use. Don't play fast 'n' loose with it, but in this instance, it's not a consideration.

Another way to think of this is imagine the cable is a hose, for Voltage we're considering the pressure we can put through the hose before it bursts. That's a function of the cross-sectional area of the hose wall and its construction materials. The width of the conductor is the flow-rate (current).

If you've ever replaced an HT lead on a car or lawnmower spark plug (US terminology might be different) you'll think it's a very thick cable, but the conductor inside is often a single strand of very thin copper with a very thick insulator as although it's very low current (flow rate) the potential (pressure) is very high.

Guessing that you're in the US, 7A @ 110VAC is 770W, that's quite a lot of power for a device like and I doubt that this machine requires anything near that, even considering it's age. This isn't going to be your problem. I would guess it draws something like 100-150W at full tilt, which is 1-1.5A, well within the specification of your cable.

Basically, it's not a cable related issue.

Thanks, power rating of the machine is "130 watts". I guess I'm gonna' have to get it apart, then.

Yep, that's makes sense.

If you want to work it out, we can go to basic Ohms law:

130W = ? Amps x 110V;

Re can then rearrange this to:

130/110 = 1.2A

So if you ever need to work out what sort of cable you should use, just divide the Power rating (Watts) by your Voltage, which stateside is usually 110VAC. That will tell you the current that the device uses (Amperage).

This is all 'nominal' meaning it's just nice round numbers, your actual supply voltage is probably between 90-130VAC and there are many obfuscations when you're working with AC, but this will get you 99% of the way there for general calculations for the non engineer. The 'nominals' are fine for working with questions like this.

This device should have an internal fuse of 1.2A (or thereabouts), this means it can't draw more than that without popping the fuse anyway, so the 7A cable is more than adequate.

Thanks!...Guess I'm gonna have to try and open it up. Are you aware of any techs on YouTube who'd be able to do like a video call so they can try and help me through it? Paid handsomely, obviously.