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Tempest

IIfx Won't boot

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I figured I'd better start a different thread about this issue as the monitor thread wasn't really appropriate. If the mods feel otherwise feel free to close this thread.

 

The topic says it all. My IIfx won't boot. I get the start up chime, but nothing after that. I can hear what sounds like two faint clicks coming from the speaker shortly after the chime and the keyboard lights flash briefly but there's nothing else. I put two new batteries in it, removed all the cards, unplugged the internal HD, but still nothing. At this point all that's plugged in is the disk drive and keyboard, but it never accesses the disk drive. I've made sure all the memory is seated properly and tried resetting the PRAM. The motherboard looks good and there's no corrosion or blown capacitors.

 

It tried to access the HD and disk drive the first time I turned it on, so I don't know what's changed since then.

 

Tempest

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This behaviour sounds just like that of my 840av before I washed the logic board. (I know, it needs new caps really.) Much a-goo about everything, as it turned out, though on first inspection, I thought the l.b. was fine.

 

Conductive residues can be hard to spot and a little goes a long way.

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Leaking capacitors do not usually explode; they usually leak a barely visible (as in, transparent) conductive liquid which spreads widely, being oily.

 

The solution to this is (a) to clean off the conductive liquid (aka "goo" in my previous post), and (B) ultimately to replace the capacitors. Apart from it being a necessary procedure if the caps have failed, since the electrolytics that will then have leaked out will be wreaking havoc, I find (a) to be good for a quick diagnosis, even if not a long-term solution. The long-term solution is (a) and (B).

 

Although it has never happened to me, I gather that (a) alone may not be sufficient in some cases, as the lack of (B) can keep a machine from working altogether, since capacitors are meant to regulate the power supplied to components on the board. An example of how this can impact a machine comes from an SE/30 of my acquaintance. Worked intermittently without anything plugged into its PDS slot. Would not work at all with the additional load put on it when an ethernet card was plugged into the PDS slot. Failed capacitors were the problem.

 

A logic board can be washed in medical alcohol (this also reduces the temptation to lick the board that might come from using single malt whisky), in distilled water, in a dishwasher (no soap and empty otherwise), in the sink, or in the shower. I have done them all and have not ruined anything yet on some 10-12 machines that have needed such treatment. I find a hand-held shower with a good spray works very well, but note that we do not have hard water in my area; YMMV. Remove all cards etc., and dry the board thoroughly before reassembly.

 

Seek and ye shall find: there are lots of posts about this on here.

 

The other thing to note is that you do need actual termination on that scsi bus. You do have the drive terminated, definitely?

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I was under the impression that the IIfx had NO electrolytics on the logic board. I could be wrong, but that's what I seem to remember. I know for sure that the Quadra 700 doesn't have any, so I could be getting this confused.

 

If there's a startup sound and no death chime, that could mean:

 

A. The ROM is crashing or stalling for some reason, possibly PRAM. I would zap the PRAM and reseat the ROM SIMM. I would also let it sit for a length of time and see if anything happens.

 

B. Because you don't have a monitor set up, it could actually be functioning properly and not able to boot from the hard drive. Try inserting a floppy disk. If it eventually spits it out or boots from it, you know that the IIfx is working properly and it's just a video and hard drive problem.

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Already tried resetting the PRAM (got the second Chime) and reseating all the RAM and the ROM. Nothing. I have a disk in the drive, that's what I'm trying to boot from, but it never starts the drive.

 

How long would it take for the system to do its RAM check if the RAM was full? I know it took my Mac Plus about 20 seconds or so to do 4MB, maybe it's just taking a long time to do the check? Then again I've left it on for 3 to 4 min so I doubt that's it.

 

Tempest

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Make sure you get at least to the third chime when resetting the PRAM. Not everything is reset only on the second chime.

 

We also can't rule out a bad floppy drive. Do you have a way to test the drive in another Mac, or use another Mac's auto-inject floppy drive? Manual inject drives almost certainly will NOT work in a IIfx.

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Tried the PRAM reset again, no dice. I suppose the disk drive could be bad, but its not even hitting once. It's like the system is just sitting there waiting for something.

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My guess is that it's not even getting to the point in the boot sequece where it tries to read from a floppy. Video would defintely help here. It seems to be past the ADB check since the keyboard is blinking. I'll check my book when I get home to verify what occurs between the ADB test and checking for a boot floppy. It could be ROM, RAM, SCSI (this is my bet)...

 

I'll look through my video cards to see if I have one compatible with your monitor... if not, I have monitors we can use to test it too.

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Already tried resetting the PRAM (got the second Chime) and reseating all the RAM and the ROM. Nothing. I have a disk in the drive, that's what I'm trying to boot from, but it never starts the drive.

 

How long would it take for the system to do its RAM check if the RAM was full? I know it took my Mac Plus about 20 seconds or so to do 4MB, maybe it's just taking a long time to do the check? Then again I've left it on for 3 to 4 min so I doubt that's it.

 

If it has 128 MB of RAM it can take quite a while, but IIRC, 3 - 4 minutes should be more than enough. I timed it a couple of times, and my vague memory says about 1.5 minutes, but I don't remember for sure.

 

In response to earlier postings: All the IIfx boards I've seen have all tantalum caps and no electrolytics. Tantalums fail by exploding, not by leaking, but that's typically when they're installed backwards.

 

Um, let's see. The jumpers. I don't know what they're for. I do know that if they're installed wrong the machine won't boot. I don't remember how they should be configured. I would have to look at my machine at home.

 

Try taking all the memory out of the machine and see if the behavior is different. The IIfx is a little odd in that with 32K of SRAM cache on the logic board it will chime without RAM, although I think it later makes an alert sound for the lack of RAM, but I'm not sure. So try it without RAM to see if there's any difference in behaviour. If not, perhaps you have bad RAM.

 

What do your RAM SIMMs look like? Eight or nine chips on one side of a circuit board? Or something unusual?

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I took out all the memory and I still get the chime, but no keyboard click or light flash.

 

There are two different brands of memory stick in the machine. Four of each

 

NEC

421000-80

9045FU022

 

OKI

m511000a-80j

904555D1

 

Both have eight chips on one side. The NEC memory says PSI Integration Inc. and L.A. Components © 1990 NTX-4/16M on the back. The OKI just says Astronic. I'm guessing they're 16MB memory sims then?

 

Oh and the jumper is in J103 not 106.

 

Tempest

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Try installing only 4 matching RAM SIMMs in RAM Bank A, leaving Bank B empty. Then try the other set of 4 matching RAM SIMMs in Bank A, again leaving Bank B empty. If it still doesn't work either time, this makes it considerably less likely to be a RAM problem.

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Ok interesting little development. On a whim I put all the memory back in and plugged the IIgs monitor into the card. The monitor isn't perfect, but I can sort of see what's going on with a little adjustment (the picture is duplicated, in B&W, and there's a bar down the middle, but I can see). The machine starts up and right after the chime I see a SuperMac logo and then the ? Disk image. It all happens fairly fast and it never tried to go to the disk drive (HD is still unplugged). Shouldn't it at least take a little time to do the memory check?

 

Tempest

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Can you tell, is the question mark blinking on the disk?

 

Disk drive troubleshooting:

 

When the Mac is first powered on, there should be a chirp from the stepper motor that moves the heads in the disk drive. If this does not occur, there is a problem with the disk drive, or the drive is not getting power. If you hot-plug the drive (generally safe), each time it is plugged in, it should chirp. (The disk drive is moving the heads to the zero-point.)

 

When you insert a disk, the disk drive should spin for a short moment (~1 second) to engage the hub in the center of the disk. This makes a smooth metal rubbing noise followed by a click. You can verify by viewing the platter on the bottom of the drive. If it does not spin, there is a problem with the drive, or the drive is not getting power.

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It all happens fairly fast and it never tried to go to the disk drive (HD is still unplugged). Shouldn't it at least take a little time to do the memory check?

The Mac IIfx is FAAAAAST! hehehe

 

That's why everyone wants one. I'll be honest, it's sure looking like a bad floppy drive or bad ribbon cable that connects the floppy drive to the logic board.

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On top of making noises, the floppy drive should should eject any disk that it can't boot from. So, just the fact that it's getting to a blinking "?" and NOT booting or ejecting the disc is a good sign that the drive could be bad.

 

You could try plugging the floppy drive into the other socket on the motherboard just for something to do.

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Yeah I tried that, it still doesn't work. I'm starting to think the floppy has died. I do have a spare Superdisk drive that got out of a dead Classic that I can try. IIRC it didn't work, but it at least made noises unlike this drive.

 

Tempest

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id put a multimeter on it and at least see if its putting out 12v and 5v on the drive power lines, regardless on how much power your drawing from it, your not going to get very far if your +5v is actually +1.8v

 

there is some big juicy caps inside the psu that if failed can cause all sorts of issues

 

(and if you dont have a meter, ask around, someone you know has one and it doesnt have to be the best one ever made)

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Yeah I tried that, it still doesn't work. I'm starting to think the floppy has died. I do have a spare Superdisk drive that got out of a dead Classic that I can try. IIRC it didn't work, but it at least made noises unlike this drive.

 

Tempest

 

I've probably got a drive laying around my place that you could test it with.

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If AfterMac's spare drive hooked up I now get a disk with a red X through it. The drive never actually tries to read the disk though (no noise) and I know the disk is good anyway. If I manually eject it I get the disk with the ? again.

 

I'm totally stumped now. Could the drive controller chip be bad? Perhaps I need to rip a working System 6 HD out of one of my other Macs and see if the IIfx will boot from it?

 

Tempest

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