Wednesday, May 16, 2007

Picture But No Sound?



This happens occasionally in our Prairie Lakes AEA Lending Library. A school will return a videotape with a Post-In note attached, saying that when they played the videotape, there was a picture but no sound. Most of the time, the sound is there but the school VCR could not find it.

If this happens, here is the “short answer.”

1. Look at the remote for your VCR. Is there a button marked AUDIO (or perhaps SOUND)? If so, press the button.

2. If you don’t have an AUDIO or SOUND button, then you’ll have to access the MENU for your VCR. What you want to do is change the AUDIO output from HI-FI to NORMAL.

Every menu looks a little different, so I can’t post detailed instructions for your specific equipment.

All right, if you would like to know the theory behind what we just did, here is the “long answer.”

On every VHS tape, the following information is recorded:

A: This is the NORMAL (or LINEAR) audio track. Every VCR, even the oldest RCA SelectaVision VCR from 1977 records audio here.

B: This is the VIDEO TRACK. As you can see, the video is recorded as stripes on an angle.

C: This is the CONTROL TRACK. The control track records 30 electronic pulses per second that are used to synchronize the tracks.

For many VCRs, including very old and very inexpensive ones, this is everything that’s recorded on the tape.


D: Most newer VCRs also are able to record and playback audio in high fidelity sound, or HI-FI. The HI-FI track is embedded in the video track. Our illustration shows the HI-FI track in red.

Sometimes, because of equipment failure or operator error, a Hi-Fi audio track is recorded with no sound. (It’s like there is a highway with no cars on it.) When you play such a tape, your VCR senses there is a Hi-Fi track and plays it. But no sound was recorded on that track…it’s just an empty audio track. So you have picture and no sound.

The solution is to tell your VCR to quit horsing around and just play the NORMAL audio track.


If you are lucky enough to have the remote handy, and if the remote has an AUDIO button, it’s a simple matter to switch from HI-FI to NORMAL audio playback. If that’s not an option, then you have to open the MENU on your VCR and find the AUDIO or SOUND command, and switch that to NORMAL.

Unfortunately, we do sometimes discover a tape with this problem in our library. By selecting the NORMAL audio track playback on your VCR, you will be able to work around this problem and show your video tape in class as planned.

7 comments:

Anonymous said...

Thanks. This was amazingly helpful.

tebeth05 said...

It's playing sound but now we have an annoying buzzing/humming sound I. The background

Unknown said...

I know this post is several years old but I just stumbled across it today and wanted to say Thank you so much! This was really helpful and the best explanation I found. I'm so happy to figure out that we didn't lose the sound after all on our wedding video! (And maybe after 25 years we should get it converted to DVD before it really does deteriorate.)

Roberta said...

Thanks so much. Happy to find your instructions which I followed, changed Hi_Fi to Normal, but it did not bring back the sound on my Zenith VCR.

Any other suggestions would be welcome!

Thanks so much.

Aloha,
Roberta

Ed Zimmerle said...

Answering tebeth05's comment, a buzzing sound could be a short in a cable. You might try using a different cable from the VCR audio out to the TV.

Michelle, glad this is useful to you. And yes, get those VHS tapes transferred to DVD before they fade away.

Roberta, look at the back of your VCR. Does it have separate audio outputs for HiFi and Normal Audio? If so, run the audio cable from Normal Audio to your Audio Input on your TV.

Roberta said...

Ed, thank you so very much!! I checked and there isn't 2 outlets but I found another cable from the VCR video plug that I plugged into the audio on the TV and bingo the sound came on!! The cable end doesn't even have the right connecting end for the TV but I pushed it in enough to make contact.

I still don't understand why it's always had the audio and then it just quit!

Thanks again for taking time to help me. Prayers answered!

Aloha

Unknown said...

I have the control and press audio, but nothing shows up on the screen to change it to Normal.