I recently got hold of a used Optiplex 745 (Intel E6400 CPU @2.13GHz, 2GB RAM) which seems, from an almost complete absence of internal dust, to have been very little used.
It works perfectly other than the problem described in the thread title. When it's switched on, "sometimes" (maybe 2 out of every 3 attempts), the screen freezes on the Dell boot splash page with the progress bar (between Optiplex 745 and BIOS 2.6.6) stopping well before reaching the end of its travel.
It seems to stop either half-way through (under the "7" in Optiplex 745) or after only 25% of its travel.
It's interesting that it stops, apparently, at exactly one or other of those two points every time.
Immediately after, if I switch the machine off and back on, it will boot perfectly about 95% of the time. Otherwise, I might have to stop/restart a third time to get it to boot.
While Google has found countless instances of Desktops freezing while displaying the boot splash, all that I've come across seem to be "permanent" problems. In other words, booting is just not possible. In my case, however, I can boot and the machine seems to be working perfectly other than this occasional glitch.
Can anybody shine a light on what might be happening here? And should I be worried?