schwrtze@csd2.UUCP (Eric Schwartz group) (09/03/85)
I have seen quite a few notes go by about this problem. Having had 2 supply problems requiring board replacement this is how I have so far successfully dealt with this problem. A muffin fan of ~3 1/4 " sq. is placed over the rear left vent ducts (looking from the front of the unit). The airflow is in a 'pull mode' i.e. air is drawn from the chassis. This method can be cheaply obtained via a pullout from you local electronics surplus. The fan should be supported by a box of similar dimensions and ~1" thick. (A Beeman airgun pellet box has been successfully tested). I have not had a failure with this method BUT Caveat: My two supplies died after two continuous spells of two month non-stop running. You analog people out there can fill me in about why this might happen. Hedley Rainnie. NYU brain research labs And Allied corp E/O hedley@alaya
maddog@tolerant.UUCP (Bill Arnett) (09/06/85)
> Caveat: My two supplies died after two continuous spells of two month non-stop > running. My Mac (very early model dealer upgraded to 512K) has been on continuosly for most of the last year (using screensaver). Do the new power supplies have a problem the old ones don't? Or am I just lucky?? -- Bill Arnett {ucbvax,nsc}!tolerant!maddog Tolerant Systems, Inc. San Jose 408/946-5667
jer@peora.UUCP (J. Eric Roskos) (09/09/85)
> My Mac (very early model dealer upgraded to 512K) has been on continuosly for > most of the last year (using screensaver). Do the new power supplies have a > problem the old ones don't? Or am I just lucky?? This re-raises a question I asked some time ago, but got no answer to... According to the Feb. '84 (had some great articles in it besides the ones on the Mac :-) ) issue of Byte, the first Macs released had a different power supply from the one intended to go in the Mac (which I think George Crow designed), because the intended power supply hadn't been completed yet. Do the more recent macs have a different power supply from the first ones, or did they go on using the original one? How can you tell? -- Shyy-Anzr: J. Eric Roskos UUCP: ..!{decvax,ucbvax,ihnp4}!vax135!petsd!peora!jer US Mail: MS 795; Perkin-Elmer SDC; 2486 Sand Lake Road, Orlando, FL 32809-7642