Okay, since the Dash update earlier in the year that allowed for bigger capacity discs, my 360 (Elite) has sporadically given me problems with some (not all) 360 game discs, whereby it wouldn't recognise them or it would think they were 'mixed media' discs or video DVDs. It only happened once in every while, and a quick eject & re-insert would resolve it, so I wasn't that bothered. Up until that update I'd never had a problem at all before with the drive.
However, I've been taking part in the new Dashboard update preview and, since installing the Dash, the problem has become a whole lot worse. Some of my 360 games will take 10+ attempts before the console will recognise them properly. During the reading process, the drive makes all manner of unnerving sounds that aren't the usual sounds it makes when things happen normally. Also, it can take the console a good 30 seconds sometimes just to read a disc before reaching the decision that it either doesn't recognise it or thinks it's something else. Before installing the preview Dash, I'd never had the reading process happen so regularly or take so long.
I've been through the preliminary steps mentioned on the forum and at Xbox Support. I've cleaned discs, cleared the 360's cache, tried without the hard drive connected, removed any USB peripherals - but the problem persists (and it certainly made re-installing all the updates for my games a long & drawn out affair). I'm convinced the problem is related to the update(s) and not console parts-related because of the way it's got worse since the Dash preview was installed, and because the problem only arises with certain games in my collection. Some games I can insert/read/play/eject/swap/re-insert until my heart's content and nothing untoward happens, but other games will be problematic absolutely every time I put them in. Also, once problematic disc are acknowledged properly, there's never any further problems while that disc is in the drive, as though there never was a problem. Finally, to add to that, no other disc types or formats give me any trouble whatsoever. Music CDs, mixed media CDRs, DVD video, mixed media DVDRs - they all work fine. If it's a problem with the parts within my console, then it's very selective as to when it presents itself.
So, can anyone offer me any practical suggestions?
I haven't put in a repair request yet because I don't much savour the thought of arguing with MS about paying for a fault which, as far as I can see, I haven't caused.