Super clean (but slightly sick) Mac Plus
I picked up a very clean Mac Plus with all the trimmings - 40mb CMS external HDD, even the original cover. She boots System 6.0.8 beautifully but intermittently locks up - at least that's what it did prior to my opening the case. I carefully opened it up to visually inspect the components. Everything at least looks in good shape. Absolutely no leaky/popped caps, etc. I carefully removed the 30pin SIMMS and cleaned the edge connectors with a pencil eraser. I did a bit more housecleaning before I reassembled it. It booted right up but after awhile now it randomly reboots. I am beginning to suspect bad RAM. I am an old-school computer technician, and am pretty good at what I do but I cannot troubleshoot board-level component failure. I'm thinking of replacing the 4 256k sticks. Any ideas where I could obtain some? Thanks in advance! -- - You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to vintage-macs@googlegroups.com To leave this group, send email to vintage-macs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/
Re: Super clean (but slightly sick) Mac Plus
--- On Mon, 6/27/11, poopoopoopoo countjim...@gmail.com wrote: I'm thinking of replacing the 4 256k sticks. Any ideas where I could obtain some? May as well go for 1 meg SIMMs to max out the RAM. You'll have to find surplus or used SIMMs. Try the LEM Swap e-mail list or someone on here might have some. Non-parity is the type needed but parity ones should work, the Mac will simply ignore the 9th bit. The only 68k Mac to require parity 30 pin SIMMs was the IIci some US Government agencies used. It had an extra parity controller chip on the motherboard. Civilian IIci versions have an empty spot for that chip. -- - You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to vintage-macs@googlegroups.com To leave this group, send email to vintage-macs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/
RE: Super clean (but slightly sick) Mac Plus
If it will handle parity chips, I've probably got some around somewhere (of of PC's) that I could spare... I always assumed Mac's had to have non-parity... Wesley -Original Message- I'm thinking of replacing the 4 256k sticks. Any ideas where I could obtain some? May as well go for 1 meg SIMMs to max out the RAM. You'll have to find surplus or used SIMMs. Try the LEM Swap e-mail list or someone on here might have some. Non-parity is the type needed but parity ones should work, the Mac will simply ignore the 9th bit. The only 68k Mac to require parity 30 pin SIMMs was the IIci some US Government agencies used. It had an extra parity controller chip on the motherboard. Civilian IIci versions have an empty spot for that chip. -- - You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to vintage-macs@googlegroups.com To leave this group, send email to vintage-macs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/
Re: Super clean (but slightly sick) Mac Plus
Hi, Saw your post. I have a large bag of 256K and 1M 30 pin simms available. I still have a IIsi that I can test them in. Let me know if you're interested. Your choice - $10 shipped. Tom On Jun 27, 2011, at 9:56 PM, poopoopoopoo wrote: I picked up a very clean Mac Plus with all the trimmings - 40mb CMS external HDD, even the original cover. She boots System 6.0.8 beautifully but intermittently locks up - at least that's what it did prior to my opening the case. I carefully opened it up to visually inspect the components. Everything at least looks in good shape. Absolutely no leaky/popped caps, etc. I carefully removed the 30pin SIMMS and cleaned the edge connectors with a pencil eraser. I did a bit more housecleaning before I reassembled it. It booted right up but after awhile now it randomly reboots. I am beginning to suspect bad RAM. I am an old-school computer technician, and am pretty good at what I do but I cannot troubleshoot board-level component failure. I'm thinking of replacing the 4 256k sticks. Any ideas where I could obtain some? Thanks in advance! -- - You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to vintage-macs@googlegroups.com To leave this group, send email to vintage-macs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/ -- - You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to vintage-macs@googlegroups.com To leave this group, send email to vintage-macs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/
RE: Super clean (but slightly sick) Mac Plus
Random reboots often point to the voltage of the PSU being out of specs. Measure the 5 and 12 volt lines through the external floppy drive connector. Take Care, Nico -Oorspronkelijk bericht- Van: vintage-macs@googlegroups.com [mailto:vintage-macs@googlegroups.com] Namens poopoopoopoo Verzonden: dinsdag 28 juni 2011 6:56 Aan: Vintage Macs Onderwerp: Super clean (but slightly sick) Mac Plus I did a bit more housecleaning before I reassembled it. It booted right up but after awhile now it randomly reboots. I am beginning to suspect bad RAM. -- - You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to vintage-macs@googlegroups.com To leave this group, send email to vintage-macs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/
Re: Super clean (but slightly sick) Mac Plus
On Jun 27, 11:56 pm, poopoopoopoo countjim...@gmail.com wrote: I picked up a very clean Mac Plus with all the trimmings - 40mb CMS I did a bit more housecleaning before I reassembled it. It booted right up but after awhile now it randomly reboots. I am beginning to suspect bad RAM. Most likely the power supply is marginal and every time an event draws a little too much power the voltage dips below the level that will support the CPU, and it resets. See this document for details: http://68kmla.org/files/ In brief, you'll want to measure the 5V supply with a voltmeter and if low, measure the 12V supply (they're linked rather than individually regulated). If they're both low, then you can adjust the internal pot. to raise the 12V back up to nominal and get the 5V back up as well. If the 12V is nominal and 5V is low then some components need replacing. If adjusting the pot. won't bring the voltage back up to nominal, then some components need replacing. Jeff Walther -- - You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to vintage-macs@googlegroups.com To leave this group, send email to vintage-macs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/
Re: Super clean (but slightly sick) Mac Plus
On Jun 28, 8:17 am, Wesley Furr wes...@megley.com wrote: If it will handle parity chips, I've probably got some around somewhere (of of PC's) that I could spare... I always assumed Mac's had to have non-parity... Wesley I have all 4MB SIMMs in my IIci and I used to have all 8MB SIMMs in the IIci and the SE/30, which gave that one like 128MB or something ridiculous like that. You might go for that rather than just 1MB SIMMs, and maybe also upgrade to 7.5.3 like me, now that it's free. You'll find a lot of improvements over OS 6. I also got a video card out of an 8100/80 PPC that work fine in the machine and found a DayStar 68x030 or 040 upgrade card that fit in the Cache slot, which left me with a Cache card... I really need to get on the Swap List... Regarding the SIMMs, I've used the same 30-pin units in all kinds of old Macs (IIci, IIsi, SE/30, LC II, etc, etc.), as well as some Sun SparcStation 3's and they all came from a huge pile of old PCs I had. Parity is preferable to non-parity in every machine that supports them, as it adds a level of redundancy and supposedly improves performance. The only people who would disagree are maybe folks trying to sell you non-parity SIMMs... About the random restarts, try opening it up and pulling the PSU. It could be a connection issue and after you test the voltages (like the other guy suggested), you can clean the connectors and re-seat it, which may solve the issue too. Another idea is re-installing the OS, and maybe swapping out the power cable (this has worked for me). Hope this helps. My IIci didn't power up the last time I tried it, so I may be in a similar situation and the possible causes are manifold. I also have a huge bag of 1-4MB SIMMs, so if you can't find good matched sets of parity memory, let me know and I'll throw some your way. Best of luck! -Joel -- - You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to vintage-macs@googlegroups.com To leave this group, send email to vintage-macs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/
Re: Super clean (but slightly sick) Mac Plus
On 28 Jun, 2011, at 11:27 AM, Jeff Walther wrote in reply to poopoopoopoo's msg: On Jun 27, 11:56 pm, poopoopoopoo countjim...@gmail.com wrote: I picked up a very clean Mac Plus with all the trimmings - 40mb CMS I did a bit more housecleaning before I reassembled it. It booted right up but after awhile now it randomly reboots. I am beginning to suspect bad RAM. Most likely the power supply is marginal and every time an event draws a little too much power the voltage dips below the level that will support the CPU, and it resets. See this document for details: http://68kmla.org/files/ In brief, you'll want to measure the 5V supply with a voltmeter and if low, measure the 12V supply (they're linked rather than individually regulated). If they're both low, then you can adjust the internal pot. to raise the 12V back up to nominal and get the 5V back up as well. If the 12V is nominal and 5V is low then some components need replacing. If adjusting the pot. won't bring the voltage back up to nominal, then some components need replacing. Jeff Walther Jeff is most likely correct. That is one of the main causes that I have seen. It was worse with the IIc range, IIRC, as they ran a bit warmer. Due to the age of the Plus, I'd use the shotgun approach I use on most computer power supplies of that age -- replace all the caps. It's possible to adjust it within spec, but if it has drifted enough to cause random lock-ups, you can bet the caps have risen in ESR. (remember the thread just prior to this about motherboard/logic board caps? Same goes for this. Need help with the repair, send me a private email off-list. Regards Tom Norris -- - You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to vintage-macs@googlegroups.com To leave this group, send email to vintage-macs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/
Re: Super clean (but slightly sick) Mac Plus
On Jun 28, 2011, at 5:57 PM, Tom Norris wrote: On 28 Jun, 2011, at 11:27 AM, Jeff Walther wrote in reply to poopoopoopoo's msg: On Jun 27, 11:56 pm, poopoopoopoo countjim...@gmail.com wrote: I picked up a very clean Mac Plus with all the trimmings - 40mb CMS I did a bit more housecleaning before I reassembled it. It booted right up but after awhile now it randomly reboots. I am beginning to suspect bad RAM. Most likely the power supply is marginal and every time an event draws a little too much power the voltage dips below the level that will support the CPU, and it resets. See this document for details: http://68kmla.org/files/ In brief, you'll want to measure the 5V supply with a voltmeter and if low, measure the 12V supply (they're linked rather than individually regulated). If they're both low, then you can adjust the internal pot. to raise the 12V back up to nominal and get the 5V back up as well. If the 12V is nominal and 5V is low then some components need replacing. If adjusting the pot. won't bring the voltage back up to nominal, then some components need replacing. A common form of this problem is the computer starts up and when it goes to boot from the floppy it restarts, due to the floppy loading down the power supply too much and triggering a protection circuit that forces a reset if the 5V supply goes too low. You need to adjust the 5V supply till it is 5.00V. The 12V supply isn't very critical on voltage but the 5V is. There are three axial lead (leads on opposite ends) electrolytic capacitors all together at the center rear of the logic board. IIRC, one is +12V, one is +5V and one is -5V. Touch the (-) lead of a voltmeter to the metal chassis and check the + lead of each capacitor until you find one showing +5V (more or less). Then connect the meter across this cap and tweak the power supply adjustment pot on the analog board until it reads 5.00V. Clark Martin Redwood City, CA, USA Macintosh / Internet Consulting I'm a designated driver on the Information Super Highway -- - You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to vintage-macs@googlegroups.com To leave this group, send email to vintage-macs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/
