Hoping this is a sci.electronics.repair problem: This concerns a Panasonic = SAPT760 home theatre system which has been repaired once under warranty and= suddenly new problems have appeared. (most of which I can live with but I = was wondering if anyone here recognised the symptoms).
There is an annoying half-second lag on sound output when played through th= e SAPT-760. Panasonic HT tech support said it is caused by the (Panasonic)= Plasma TV. TV Tech support at first agreed and sent me a BIOS upgrade. Th= e lag reduced to about a tenth of a second or less (this was almost definit= ely a coincidence) and has since increased back to about a half second agai= n. If I play the TV sound at the same time as the digital HT, sound, you ca= n hear the marked lag, with the TV sound being, of course lag-less.
Other problems with the HT setup which may or may not be relevant are that = when I first got it, my Nano played and charged through the built in dock. = Now it shows incompatibility which Panasonic confirms! But I am wondering = how it played and charged formerly??
More importantly perhaps, on initial turn-on, when switching to the Toslink= input, I initially get no sound whatsoever. Leaving it on digital input, = after a few minutes, I start to hear a low frequency (3-4 hertz?) popping w= hich slowly increases to about 10-15 Hz before the unit starts to recognise= the popping as the light based sound it is supposed to be decoding and the= n the sound quality is generally OK with no popping. But with that annoying= lag. All other inputs (including the DVD) are OK, which told Panasonic Tec= h support that the unit is performing properly and that the problem must be= with the signal coming out of the TV. =20
On one call, the TV people said they found some reference to an adjustable = lag on the HT system but the HT people deny that any adjustment on this (or= resetting to defaults) exists. There IS a time delay adjustment on the DVD= side but it is set to zero.
Yes I DO know that there is some millisecond adjustment on individual speak= ers but this problem concerns a general half second lag on all speakers and= all speakers seem to be set up OK on the in-built DVD system.
One last thing: The lag isn't always there: Sometimes the toslink sound (i.= e. the sound from the tv into the HT) dissolves into a generalised cracklin= g.