Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!rutgers!labrea!decwrl!hplabs!hpcea!hpfcdc!hpfcdq!vodall From: vodall@hpfcdq.UUCP Newsgroups: comp.sys.m6809 Subject: Re: Poisonous File Bug in Level 2 Message-ID: <300007@hpfcdq.HP.COM> Date: Sun, 30-Aug-87 16:08:07 EDT Article-I.D.: hpfcdq.300007 Posted: Sun Aug 30 16:08:07 1987 Date-Received: Fri, 4-Sep-87 00:49:58 EDT References: <1939@ihwpt.ATT.COM> Organization: Hewlett Packard, TWO Lines: 32 > I don't know whether this is disk controller hardware problem, > RAM upgrade, bit-rot in OS9, or a subtle bug. > It usually doesn't happen till the system is pretty warm. > Maybe I'll have to run Commo-64 style, with the Coco case top off. > Or relocate that voltage regulator, stupidly buried in the > worst-ventilated part of the case. -- >Mike J Knudsen ...ihnp4!ihwpt!knudsen Bell Labs(AT&T) > Delphi: RAGTIMER CIS: This first thing I did to help alleviate my Coco 2's heat problem was to use an exacto knife to carefully cut out the slots above the transformer. I guess they were there to protect the 115v from falling paper clips, etc. (I won't comment on a design that leaves 115v on the circuit board with the switch off.) My final solution to the overheating was to: First, throw away the cover. It kept getting in the way of all the wires and modifications anyway. Second, purchase one of the 12v DC fans that RS sell for $15. I used a couple screws to mount the fan on the side of the Coco so it's 2/3's blowing on the regulator and 1/3 on the transformer. This gives a nice flow of air across all the ic's and everything runs real cool. Lastly, I build a variable dc supply using a LM317 regulator to power the fan. Adjustable voltage = adjustable speed = NO NOISE... Turns out I didn't need the regulator. Next time I'll just run the fan on it's minimum voltage, about 6 volts. Bill Vodall Intuitively Obvious Disclaimer: Hewlett-Packard isn't responsible for the above. Use at your own risk!!!!!!