^ it depend ..... they are series strings, like the christmas light ..... if the diode jus LED, but still act as a diode, nothing too much happens, all the others still works ..... if the diode short circuit, the string "lost" 4V of dropout voltage, and the driver can notice it and stop all ..... if the diode goes open circuit, the whole string stop to work, and also in this case, the driver notice it and stop the projector .....
Difficult that you fry the string, anyway, cause the checking circuit on the driver acts in less than half second, usually ..... only case that i can imagine, for fry the string, is if the diode "melt" something, going opened, and suddenly going back shorted, in 1/10 of second ..... in this case, the string get disconnected, and then immediately reconnectrd on the driver output, that in the interval increased the current ..... but i think is really rare, as problem .....
EDIT: also, those diodes are insanely robusts ..... i have one working at 1,2A, and for a mistake, i reverted it (positive on negative and negative on positive) ..... this usually means "instant death" ..... other than this, i turned it on and off 3 times, for some seconds, when i noticed it was not working, before notice my mistake ..... i was thinking i wasted the diode, but wanted to check it the same, and reconnected it right ..... and it still work perfectly, no strange or dark zones in the beam, and still the same power as before ..... i think i can call it "the miracled one"
..... also, if you remember, i had one of my first diodes in a "torture chamber" for see if there was some degradations, in the long time ..... initially, i had planned to get the data and post them here, but there's no "degradation data" to post, yet ..... the diode is working continuously at 1,6A, 10 seconds on / 10 seconds off, from 30/06/2010, 24/7, and til now it showed no power degradation at all ..... i'm wondering how much it can go, at this rate