Drako@cup.portal.com (Chris Del Grande) (04/20/91)
A friend of mine installed two 1 meg SIMMS chips into a Mac SE a few
days ago to achieve a 2.5 megabyte configuration, and apparently everything
went fine exceptuUpon startup, the monitor was filled with vertical black
stripes and the machine never made it past the 'Happy Mac' startup icon.
He first suspected that he had accidentally clipped the wrong
resistors (R35 & R36) but upon further examination everything was in order.
The 1 meg chips were also in the proper rows/banks, etc. All wires and cables
were intact also. The mac still would not startup properly.
He took the machine to a local Mac dealer who said it was a fried
CPU (I believe) and charged him > $400 for a replacement. Does this seem in
order? My friend says that he didn't touch any of the other components and
such, so just how sensitive are these inner components to the human presence.
Any information would be greatly appreciated...(his dad didn't appreciate the
VISA charge and would like some answers.) Thanks!
Chris Del Grande___________________________________Drako@cup.portal.combarvian@ece.cmu.edu (Scott Barvian) (04/20/91)
In article <41443@cup.portal.com> Drako@cup.portal.com (Chris Del Grande) writes: A friend of mine installed two 1 meg SIMMS chips into a Mac SE a few days ago to achieve a 2.5 megabyte configuration, and apparently everything went fine exceptuUpon startup, the monitor was filled with vertical black stripes and the machine never made it past the 'Happy Mac' startup icon. He first suspected that he had accidentally clipped the wrong resistors (R35 & R36) but upon further examination everything was in order. The 1meg chips were also in the proper rows/banks, etc. All wires and cables were intact also. The mac still would not startup properly. He took the machine to a local Mac dealer who said it was a fried CPU (I believe) and charged him > $400 for a replacement. Does this seem in order? My friend says that he didn't touch any of the other components and such,so just how sensitive are these inner components to the human presence. I've come across black stripes and/or checkerboard patterns when I've installed memory in the wrong slots and/or snipped out the wrong resistors. Are you really sure you did it right? I think there are at least 3 combinations of bank/resistor combinations, one for a Plus and for two different flavors of SE. And certainly ESD (static-induced damage) is easy enough to cause. A dry room and/or a dry day and you're just asking for trouble. But a wrist strap (grounded to a suitably safe place) just about eliminates that possibility. You don't necessarily have to touch a given chip to "zap" it- if you touched a board trace or connector and created a discharge, the "least protected" circuit is most likely to be harmed. "A fried CPU", given the symptoms you describe, doesn't sound likely. But anything is possible. I'm not a doctor. Nor do I play one on TV.
tempest@ecst.csuchico.edu (Kenneth K.F. Lui) (04/20/91)
[Stuff about upgrading an SE and the CPU ended up being fried somehow.] There are a lot of sensitive components in today's computers and it wouldn't take a whole lot to fry a component via electrostatic discharge. You don't have to actually touch anything because the charge stored in your body can leap through the air; all it takes is for the charge to touch the right place and wham! When the SE was upgraded, did you/your friend wear a grounding wrist strap? If you/your friend did, was the strap connected to _metal_ (painted metal don't count)? The environment is also important because I've opened up my SE many times (~50) without any ill effects (and this was before I knew about ESD, so naturally, I had no grounding wrist strap) for which I was grateful and very lucky. That's one possibility. Another is improper mounting of the new SIMMs. When I upgraded SIMMs in my SE to 4MB (I had upgraded to 2.5MB before without any problems) I didn't set a pair of high-profile SIMMs and I got the same result your friend did. I opened up the Mac again and after careful inspection, noticed the SIMM pins weren't in contact with their holder pins. Reseating the suspect SIMMs fixed it. Ken difficult to ______________________________________________________________________________ tempest@ecst.csuchico.edu, tempest@walleye.ecst.csuchico.edu,|Kenneth K.F. Lui| tempest@sutro.sfsu.edu, tempest@wet.UUCP |________________|
rbrink@hubcap.clemson.edu (Rick Brink) (04/23/91)
From article <41443@cup.portal.com>, by Drako@cup.portal.com (Chris Del Grande): > > A friend of mine installed two 1 meg SIMMS chips into a Mac SE a few > days ago to achieve a 2.5 megabyte configuration, and apparently everything > went fine exceptuUpon startup, the monitor was filled with vertical black > stripes and the machine never made it past the 'Happy Mac' startup icon. > He first suspected that he had accidentally clipped the wrong > resistors (R35 & R36) but upon further examination everything was in order. > The 1 meg chips were also in the proper rows/banks, etc. All wires and cables > were intact also. The mac still would not startup properly. > He took the machine to a local Mac dealer who said it was a fried > CPU (I believe) and charged him > $400 for a replacement. Does this seem in > order? My friend says that he didn't touch any of the other components and > such, so just how sensitive are these inner components to the human presence. > Any information would be greatly appreciated...(his dad didn't appreciate the > VISA charge and would like some answers.) Thanks! > > Chris Del Grande___________________________________Drako@cup.portal.com Seems like I had one SE install do that to me [I've done 50 or more] and I was the connector on the cpu board loose (I'm guessing, it may have been another connector for the diskdrive), anyway I just readjusted the connections and it came up normal. You didn't mention if there were any tones on startup, or if there were any sadmac error codes. The most common problem I ever had was bad simm chips. Dead out of the box. As I write this, it seems the simms in the wrong slots gives that stripe pattern. In any event, the problem it created, could have killed the cpu. Loose connectors can cause voltage surges that will zap that 68000 in a flash. Warning to anyone doing memory upgrades. Pay the apple shop th $50 to install the chips? Or pay the Apple shop $400 for a new logic board? They like it either way. If you aren't willing to take the risk (have no exper., etc.) don't open the box. As to weather the Apple shope ripped you off? I suppose it's possible, but apple shops don't need to be dishonest to make a good buck, the design of the Mac+ is enought to keep them rich. I hear a lot of IIsi's are putting smiling faces on them now...
tgoose@eng.umd.edu (Jason Garms) (04/23/91)
In article <41443@cup.portal.com>, Drako@cup.portal.com (Chris Del Grande) writes: > [stuff deleted...] > He first suspected that he had accidentally clipped the wrong > resistors (R35 & R36) but upon further examination everything was in order. > The 1 meg chips were also in the proper rows/banks, etc. All wires and cables > were intact also. The mac still would not startup properly. There are atleast 4 different revisions of the logic board and some require the higher density SIMMs closer to the CPU (in the back) and some require them to be farther from the CPU (in the front). Did your friend try it both ways? > He took the machine to a local Mac dealer who said it was a fried > CPU (I believe) and charged him > $400 for a replacement. Does this seem in > order? My friend says that he didn't touch any of the other components and > such, so just how sensitive are these inner components to the human presence. > Any information would be greatly appreciated...(his dad didn't appreciate the > VISA charge and would like some answers.) Thanks! Actually the most common cause of the symptom you just described is a problem with the ROMs. This can usually be corrected by just replaceing the ROMs. Many Apple dealer don't do this. (or maybe they don't realize that they can do this). A possible cheaper alternative would have been to have an FDHD ROM upgrade installed. This would only have cost about $100 instead of the $400. Jason Garms tgoose@eng.umd.edu
rubin@chocktaw.cis.ohio-state.edu (daniel j rubin) (04/24/91)
When I installed my simms, I could not get my mac to boot up correctly. I thought that I fried a cmos chip or something, but actually I just did not shove the simms in their sockets hard enough and all of the traces on the simms pc board were not making good contacts with the socket. Try to re-install the simms with a little more force.
tswift@well.sf.ca.us (Theodore John Swift) (05/09/91)
> A friend of mine installed two 1 meg SIMMS chips into a Mac SE a few > days ago to achieve a 2.5 megabyte configuration, and apparently everything > went fine exceptuUpon startup, the monitor was filled with vertical black > stripes and the machine never made it past the 'Happy Mac' startup icon. > ...He took the machine to a local Mac dealer who said it was a fried > CPU (I believe) and charged him > $400 for a replacement. Does this seem in > order? My friend says that he didn't touch any of the other components and > such, so just how sensitive are these inner components to the human presence. Hmmm... if it really made it as far as the "happy Mac" icon, then it's not strictly a fried CPU: if the 68000 itself was fried, you wouldn't even get the "bing" at start time, and it certainly woundn't have it together enough to get the Happy Mac on the screen; it would just be an 80 watt paperweight. From your description, it sounds like the dealer probably said "it's a fried CPU _board_ (as opposed to the only other board, the power supply board). Field repair of Macs is almost too simple: it's either the CPU (or logic) board, the power supply/video board, the floppy drive, or the picture tube. The dealer undoubtedly has no clue as to what's wrong, but $400 is the price of pulling the logic board, popping in a replacement, and sending the sick one back to Apple for repairs. So as far as it goes, that seems like it's "in order". But it still doesn't explain what went wrong. It's moot now, but I would go over the instructions a few more times, maybe get some independant confirmation, try the SIMMs in a known working configuration to determine that they're not the problem, etc. -- ---------------------- Ted Swift tswift@well.sf.ca.us "You bally well are informed, Jeeves! Do you know everything?" "I don't know, sir" ~P.G. Wodehouse