VHS HiFi track won't play?
 

I have a tape which has a Hi-Fi track, but it doesn't play for more than half a second every few minutes or so. The mono track is incredibly quiet - peaking at around -42 dB.

I've tried manually adjusting the tracking but that only affects the picture not the audio.

If this can't be corrected with the tracking, only another player/vcr to play this tape will help, it's always a good thing to have some vcr's in stock, for this.
I don't know if cleaning the heads will help in this case....

I've tried both a Philips VR 1000 and a Panasonic NV-HS1000.

You may have a recording alignment issue on the tapes, as mentioned in the other thread. That woudl require misaligning a deck to attempt to lock on the audio.

And, as I mentioned in the other thread, I have no idea what that means.

Linear track peaking at -42 dB is odd if the recording had normal sound levels. This could happen if for some reason the left and right input channels were reversed phase, as could happen when using an external balanced mic/source and the wrong adapters/connectors when recording.

Does the HiFI track indication stay on (if the VCR has it) during playback, or does it stay off when you hear no HiFI track?

What do you mean?

Many vcrs (including the ones you got) have indicators on the front display showing whether it's playing hi-fi or linear audio. On both I think it is L/R boxes showing under the volume meter indicators.

Right, that's off when it's only playing the mono track. The HiFi track pops in occasionally, and when it does the L/R thing lights up (actually from the small sample I had before giving up on trying it in HiFi mode, only the left channel is active anyway).

That seems like normal behaviour to me. I've had other HiFi tapes in the past where the audio has been quite crackly for a period, then it switches to the mono track for a bit, including doing so on the front display. It's just that in this case the mono is so quiet it functions the same as shutting the audio off entirely, rather than simply switching temporarily to slightly worse-sounding but otherwise acceptable audio. There have even been tapes where the HiFi crackled so much I just did it in mono instead, and it's fine.

Another possiblitity is the audio head being misaligned or dirty on the recording VCR, which results in the audio signal being off-position or have bad azimuth (angle between head and tape). It's possible to adjust these, though unlike the tape guide posts, the A/C head is stationary and it's very rare for it to go out of alignment.

Do you have any knowledge about what VCR it was recorded on? Or was it a commercial tape?

It seems to have been provided to a sports club by the network broadcasting the game.