Sidney Ho wrote... >> >>> I've had a Newer G3/240/512kb die from (partially) heat related causes (in >>> August, when temps could run 168-170F on the G3 CPU). Fortunately, Newer >>> replaced this under warranty before they went bust. Ambient temperature, air >>> circulation and the type of surface the 2400 is placed on are important >>> determinants in heat transfer efficiency. I've added an aluminum block to >>> connect the CPU directly to the aluminum pad of the lower case housing the >>> convection tube. >> >>Bob Friede replied... Any chance of a step by step how-to? Sidney replied... >Groan...Well, as lazy as I'd like to be, it's hard to refuse such a direct >request and actually a quite IMPORTANT modification. > >Heat reduction of the CPU is extremely important. The cooler it is the more >stable it will run and the longer it will live. It will even run >(un)measurably faster as heat increases conductivity resistance. The >original 603e/180 mhz runs quite hot. The Newer G3/240mhz runs hotter. In >winter, room temperature on a hard desk surface, I'm running 62 C / 143 F >under constant normal load. A summer temperature might be 10-15 F higher, >but I haven't monitored it so closely since I had to reinsert a G3/240 to >replace my failed G3/320. I turned the backside cache back down to the >standard 120 mhz from the accelerated 160 mhz. The latter does cause >increased instability and heat while little speed increase is to be noted in >the real world--or even with MacBench. With no more 2400/G3 upgrades likely >to be available, survival/reliability over speed becomes a paramount >consideration. For reference, my own MacBench 4.0 (without LibMoto) tests >scored: > >G3/240 at 120mhz 160mhz backside > >Processor 756 783 >Floating Point 597 598 >Disk 308 310 > >The modification is actually quite easy, assuming you know how to reassemble >a 2400c. > >1. Disassemble and pull out complete motherboard (MB) and I/O power board. >You will see an aluminum heat sink block about 20 x 20 mm x 2-3 mm thick, >sitting on top of a hollow cavity, with a convection pipe leading towards >the PC card cage. > >2. Take some aluminum foil sheet, fold it repeatedly until it is about the >same size (L x W) of the heat sink and about 1.5-2 mm thick (this is about >the air space between the CPU and the heat sink). Compress this foil block >to eliminate any residual air pockets and maximize its density, even >crimping the edges with pliers (if necessary). > >3. Glue (lightly) the foil block on top of the heat sink. The objective is >to maximize the heat transfer efficiency from the CPU ASAP through the heat >sink so the natural air convection can optimally dissipate heat buildup. >Replace the MB and reassemble the 2400c. The CPU will then sit flush over >the foil. I think this modification lowers CPU temperature by around 15 F, a >big difference. Thank you thank you thank you! I never would have figured this out alone... Bob Friede ---------- Duo/2400 List, The friendliest place on the Net! A listserv for users and fans of Mac subportables. FAQ at <http://www.themacintoshguy.com/lists/DuoListFAQ.shtml> Be sure to visit Mac2400! <http://www.sineware.com/mac2400> To unsubscribe, E-mail to: <[EMAIL PROTECTED]> To switch to the DIGEST mode, E-mail to <[EMAIL PROTECTED]> Need help from a real person? Try. <[EMAIL PROTECTED]> ---------- Dr. Bott | Great Duo & 2400 stuff including 10/100 Ethernet for 2400s! Dr. Bott | Duo Batts too <http://www.drbott.com/prod/alist/duo.html> NineWire | If they are cool enough to host this list... Digital Solutions | ...you should check them out! http://www.NineWire.com/ PowerBook Guy is | Click here! Everything PowerBook! | http://www.powerbookguy.com Midwest Mac Parts ][ <http://www.midwestmac.com> After-market parts for Macs. ][ 888-356-1104 ][ MacResQ Specials: LaCie SCSI CDR From $99! PowerBook 3400/200 Only $879! Norton AntiVirus 6 Only $19! We Stock PARTS! <http://www.macresq.com>
