tezza wrote:Are you sure? I could have sworn my Mac Classic II, SE30 and SE had screws inside for various bits and pieces?
Gah! Another heathen. Any Mac junkie will tell you the all-in-one computers never break. The only reason to take the cover off is to upgrade the RAM - which should be done by a true member of the church of Jobs as they are the only individuals gifted enough to wield the 'sceptre of case cracking' in anger. How dare you desecrate the impeccable doctrine of mac serviceability! (ie, 'yes, but you're not supposed to know that' - didn't I admit even the most vaunted desktop models still use screws to convert drive fixings? There simply should not be screws rattling around loose in these cases as none need to be removed to dismantle and then service the system). I better watch out what I say around here, too many engineering types.
SpidersWeb wrote:I just reinstalled the VRAM SIMM and hooked it up it to a 19" Dell with all the digital menus etc, turning the machine on and the light goes green and it picks up a 35Khz 67Hz signal but it's black. On the IBM the pattern was only visible because those displays let you set the brightness to a rediculous amount, this one doesn't.
So I think the display output works - it sets a mode, and generates HSync and VSync, but the Mac isn't trying to display anything.
I just wish it'd do something to point me in the right direction.
I expect the mac is doing it's absolute damndest to display something - it needs a repair tech to see an error number, this reports what has causing the distress of your new friend. You just have a bunch of monitors that have been manufactured to meet the (wrong for you) mass production standard of the day. Even the dell, I'd be impressed if it could manage a low 640*400. VGA cards of the vintage this would be expecting usually use line doubling to provide CGA resolutions (320*240) on (S)VGA monitors.
I recall you have some amiga tech there. If some of it roughly translates to a 1084(xx) monitor and you have a VGA to CGA cable adapter, you could try that. (I know, this monitor is rated at only 256 scan lines, but I've seen them used for 'TV resolutions' (288 vertical scan lines), you might get lucky and see a fixed picture, or even a rolling display. Your best bet is going to be searching for suitable monitors in the 14" or 15" sizes. You really need a mac monitor or true muti-frequency monitor. If it really isn't trying to display something, then it is dead to all intents and purposes.
I've been watching a discussion about upscalers on one of the BBC micro boards so that those old systems can be used with modern LCD TVs. It's something I will have to lash out on, I'm down to my last two CGA resolution monitors. May be worth a bit of research for yourself and others too. Should save a bit on power and space required if you can chuck out a few CRTs and just use a LCD screen, and may mean that you can get by using some old box and strange video output frequencies with any dodgy 'old' LCD screen.
At the end of your trials, if you don't get the 'logic board' fixed, (mac people don't say motherboard, they're too 'special for that' - though not the sort of 'special' you're thinking of) even replacing it doesn't preclude the purchase of a proper monitor. But I've been wrong about absolutely everything else so far, so what the hey.
SpidersWeb wrote:Two things I'm curious about. Firstly it has a lot of test connectors on the side of the board, is there anywhere I can get a list of acceptable values?
Secondly there is a block of pins - 3 x 2 witht he labels A20 A21 and J17 - I was wondering if there was supposed to be a jumper on one?
Mystic apple juju knowledge! Best of luck tracking down any useful service/repair manuals that tell you this. I remember a set of techie discs listed on Trade Me a few years back. (Mac service manuals on CD), they went quick and for very good money. All trusted ones who enter the temple of Jobs and are bestowed with the knowledge of trace and voltage, guard their secrets better than the Masons. Must be something in the coke that is delivered to the apple stores.
SpidersWeb wrote:On the topic of screws, other than the drives the LC has two - one to hold the case on and the other I think might've been used to mount the fan cover (which mine is missing)? But yeah I was pretty impressed when I had the motherboard out by just pressing two tabs and pulling - crazy.
Yikes. I've never known a screw to be present in the case (at the top of the back, for anybody unfamiliar with the pizza box). The case only has two clips to keep it together. I remember opening up a NEW mac LC machine at polytech after they got a couple, and was seriously worried that somebody had made a mistake that it should be so easy! (A few years ago now guys) ;op Geeze, did any other mac people know this? And fan cover? You are pulling my leg, really? I give up.
http://www.macheaven.net/manuals.php (Random url, no help whatsoever).