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brain transplant for 475

Author	Topic
muzhok New Member Germany 91 Posts	Posted - 01 Aug 2003 : 03:16:20 I noticed a 68040 33MHz processor (not the lc version) on sale on the local e-bay and thought it might be possible to replace the brain-dead chip on my Performa 475. Has anyone attempted this operation? Can the chip survive without a heat sink? The same chip on my Quadra 950 has a monster of a heat sink. Is it just a matter of "pulling out" the old chip and "pushing in" a new one? working 68ks: 2 lcs, Quadra 950 (80/4.3Gb), Mac IIsi (17/1Gb/500MB, Performa 475 (20/300Mb)
QuadraJets Junior Member USA 344 Posts	Posted - 01 Aug 2003 : 04:27:23 Yep, it will work fine, and unless you overclock it, it probably would not need a heatsink (because it will run at 25mhz). It is simple, just pry out the old chip with a small screwdriver or knife, and seat the new one in the empty socket. BUT, if you are putting a 33mhz 040 in there, why not put a heatsink on it and o/c it to 42mhz? Artillery Commander/Engineer, 68kMLA Liberated: LCII , III+, IIci, Q700, 800, and 840av, P550, 410 Contraband: Beige G3/300 MT o/c 400mhz, (2) 6100's Hotline mirror server: 68k.dyndns.org Edited by - quadrajets on 01 Aug 2003 04:29:02
wisof Junior Member USA 257 Posts	Posted - 01 Aug 2003 : 08:16:23 I just put the same processor in my Performa. Get a small flathead screwdriver and gently work it into the space between the processor and the slot. Twist the screwdriver so the flathead lifts the processor out. Do this in small increments all around the processor. Eventually it will rise out. Take notice of where the "missing" pin is on the bottom of the processor. Processor will only fit in one way, so make sure you take not of where the missing pin is. to put it back in: line up the missing pin on the new processor and place the processor on the slot. gently, apply equal amounts of pressure all around the processor. Little by little, the processor will make its way in there. there should be a small(very small) gap between the slot and the processor. (should take 10-15 minutes) Good luck! _________________________ I have a problem with vintage electronics. . .I am working on it.
muzhok New Member Germany 91 Posts	Posted - 03 Aug 2003 : 08:08:23 The price went up much too high for my finances, but I spotted another processor on e-bay that no one has bid for yet - a Motorola HX 68040 RC 25Mhz. Does anyone know if this would work in the 475? Thanks.
muzhok New Member Germany 91 Posts	Posted - 03 Aug 2003 : 13:15:27 it is the "HX" part that troubles me. The processors in my macs usually begin with "MC". Does it make any difference?
maclover5 LC Doctor/Hot Rodder Australia 5830 Posts	Posted - 03 Aug 2003 : 16:14:13 It shouldn't. Got a link for us to look at? "**** em" - Jobs in regards to customers Warrior maclover5 68kMLA Official 68kMLA Detective Number of 68ks Liberated: 7 Number of Contraband (PPC) Liberated from the Dumpster: 1
SiliconValleyPirate Junior Member United Kingdom 273 Posts	Posted - 03 Aug 2003 : 16:29:32 I would suspect the HX means it's a different package type. I have a 68000 manual from Moto that lists them all somewhere. OK the 68000 manual doesn't list the HX suffix but it does tell me tere are 4 different main types - PGA (pin grid - like the Mac ver.), Quad Pack (contacts arranged around the 4 sides for a push-in socket - used for Mac FPUs), Leadless (same as quad pack but uses small indents with the actual contacts in the socket - may also be used for Mac FPUs) and SIP - which is a long one with pins down 2 sides like they used in the Mac and Mac Plus. Insist on seeing a photo. -- Mark Benson FlatPackMacs http://fpm.gotdns.com 2nd Lieutenant - 68kMLA, LC Quartermaster Holder of the Crowbar of Persistant Crate Opening "Never send a human to do a machine's job" - The Matrix
muzhok New Member Germany 91 Posts	Posted - 03 Aug 2003 : 23:08:14 The very fuzzy photo just shows the top of the chip and therefore looks like a "normal" 68040. I will write the seller and ask about the type of pin grid. If things work out, I will get back to this thread. Thanks for the tips!
muzhok New Member Germany 91 Posts	Posted - 03 Aug 2003 : 23:18:20 Oh yes, and the photo link: http://ebay1.ipixmedia.com/abc/M28/_EBAY_8fbb28703623ed093853827d39347142/i-1.JPG I can hardly read the fine print!
tmtomh Junior Member USA 172 Posts	Posted - 04 Aug 2003 : 05:22:15 That sure looks like the right thing, but I'm not making any guarantees... M No rank Permanent 68k roommates: - "PowerMystic" Color Classic, 66MHz PPC601 card, full '040, 36/1.2G/enet, OS 8.1 - "Mystic" Color Classic, full '040, 36/700/enet, OS 8.1
wisof Junior Member USA 257 Posts	Posted - 04 Aug 2003 : 08:50:00 yeah, pretty fuzzy, but they look like 68040 _____________________________________________ I have a problem with vintage electronics. . .I am working on it. Performa 630CD Centris 610 Quadra 950 Quadra 605 Giant 80mb SCSI HD
maclover5 LC Doctor/Hot Rodder Australia 5830 Posts	Posted - 04 Aug 2003 : 16:02:28 Yeah, definately. "**** em" - Jobs in regards to customers Warrior maclover5 68kMLA Official 68kMLA Detective Number of 68ks Liberated: 7 Number of Contraband (PPC) Liberated from the Dumpster: 1
muzhok New Member Germany 91 Posts	Posted - 14 Aug 2003 : 14:49:01 Finally installed the 68040 33MHz into the Performa 475. Quite pleased as it only cost me a total of 5 euro bucks and I did find the performa in the trash, after all. I have a question similar to the one recently posed by vortex. The processor is now "underclocked" - running at only 25 MHz with a Macintosh ID = 89, and I don't have any pressing need to increase the speed. The processor is still quite warm to the touch - if not downright hot. I do not have a heat sink for it and in fact have seen no heat sinks for such processors on the German e-bay. Is it in fact necessary, seeing as how it is running at the same setting as its 68LC40 25 MHz predecessor? Is there a "do it yourself" heat sink solution? I also have a number of fans from old mac lcs, although I don't know how one on top of the processor would be fixed, nor whether the cover would shut. Any suggestions?
Jobf Junior Member United Kingdom 162 Posts	Posted - 15 Aug 2003 : 11:10:58 No need for a heatsink, but put one on if it makes you feel better. I got a low profile heatsink off a Pentium 75. I applied some thermal paste and stuck it to the 040. Works great, and the lid shuts too! BTW: You should definately clock-chip it. Chipping it to 33mhz gives you a speed boost of 33%! Not bad for 5mins work, and its not hard.
tomlee59 Starting Member USA 46 Posts	Posted - 15 Aug 2003 : 14:03:41 Here's an approximate rule: If it's cool enough for you to touch it indefinitely (even though it might be uncomfortable to do so), it's cool enough for the electronics. Most people can (barely) stand to touch a ~60C object, and that's ok for silicon circuits (the actual chip will be hotter still, but a 60C case temperature usually implies a safe chip temperature). If it's too hot to touch even for a short time, then you need to provide additional heatsinking, and/or add a fan. Cool chips live longer and can run at higher clock rates. If you plan to overclock, additional cooling gives you higher reliability overall.
Macintosh�OrInBetween Starting Member 8 Posts	Posted - 23 Aug 2003 : 11:35:19 My LC 475's CPU is labeled XC68LC040RC25, and it looks like a PGA chip with pin pattern/chip size close to the Intel (boo hiss) i486DX2/66 in my FTP server. (I don't have a lot of macs. I could probably get more power out of a stack of LC-III's the same size as this old IBM tank.) Rank: Technician 68k's Liberated: Macintosh SE, Macintosh LC 475. 68k-related Equipment: ImageWriter II
muzhok New Member Germany 91 Posts	Posted - 24 Aug 2003 : 01:12:49 Got a connection for a heat sink the other day and will probably pick it up towards the end of next week. Read the clock-chipping page (http://homepage.mac.com/schrier/q605.html)and regret that I didn't picked up that soldering kit at the flea market. I guess I will just have to stay at 25 MHz for the time being. If I do find a fan, do I just connect the power in parallel to the mac's cooling fan? Thanks.
maclover5 LC Doctor/Hot Rodder Australia 5830 Posts	Posted - 24 Aug 2003 : 01:31:28 I piggyback it on the hard drive power cable. "**** em" - Jobs in regards to customers Warrior maclover5 68kMLA Official 68kMLA Detective Number of 68ks Liberated: 7 Number of Contraband (PPC) Liberated from the Dumpster: 1

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