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Tempest

IIfx Won't boot

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If AfterMac's spare drive hooked up I now get a disk with a red X through it.

I assume the X appears red because of your unusual monitor setup. In actuality the X is likely to be black.

 

I have trouble understanding your wording. Are you saying that you are trying a different floppy drive, one from AfterMac? Are you sure that this is a known-good auto-inject floppy drive?

 

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 fixed a floppy drive recently that did that. Transistor Q4 had gone bad. My drive appeared dead but it would still make the X on the screen.

 

I'm totally stumped now. Could the drive controller chip be bad?

Very unlikely.

 

The drive could be faulty.

The drive could be manual-inject instead of auto-inject.

The drive may not be receiving proper voltage.

 

To test the voltage in the most crude, simplest way (fairly safe procedure):

With the IIfx ON, unplug the floppy drive. Lightly plug it in and unplug it several times with you ear next to the floppy drive. If you hear a small motor chirp noise inside the drive each time you plug it in, the drive is getting power. This also verifies Q4.

 

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?

The Mac will almost certainly be able to boot from a hard drive, but it will not help fix the floppy drive problem.

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Dennis, to answer a couple of your questions, yes the drive is auto-inject, but it's not necessarily known working. It was working when it was pulled quite a while ago, but I did not test it again before letting Tempest borrow it. We were both attending the same event and I just grabbed it on my way out the door.

 

My guess at this point would be a lack of power to the drive. You should be able to hear it do *something*.

 

You could pull the HD from another Mac and try to at least get it to boot and get the video problem resolved. You could also test the floppy drives in your Classic just to verify that they are working.

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My guess at this point would be a lack of power to the drive. You should be able to hear it do *something*.

The drive must be receiving +5V because of the X floppy icon. This proves that the logical part of the drive is functional and communicating with the Mac successfully, which suggests that the SWIM chip is also doing fine.

 

The motors are not running, however. This can only mean one of two things:

 

  • +12V supply at floppy connector from the Mac IIfx is not working
  • Problem with the disk drive

 

You could pull the HD from another Mac and try to at least get it to boot and get the video problem resolved. You could also test the floppy drives in your Classic just to verify that they are working.

That sounds like a perfect plan, aftermac. Swapping drives with another Mac will be a PERFECT diagnostic.

 

Known-good floppy drive in IIfx works -> It was just a bad floppy drive. Problem solved.

 

Known-good drive in IIfx does not work -> We know it's either the logic board or the power supply.

 

Hard drive spins in the IIfx -> Verifies +12V, rules out power supply. Problem is on the logic board.

 

Hard drive does not spin -> We would need to find where we're losing the +12V. Could be on the logic board or in the power supply.

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I'll crack open my spare SE tonight. Not only does it have two floppy bays (which means I won't have to take the other one out), it also has a good working HD installed. I can kill two birds with one stone.

 

Tempest

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I'll crack open my spare SE tonight. Not only does it have two floppy bays (which means I won't have to take the other one out), it also has a good working HD installed. I can kill two birds with one stone.

 

Tempest

 

Keep in mind that in the SE, it will only function as an 800K drive... if I remember that's what your SE was, but at least it should tell you if the drive is working.

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Ok got some testing done, not good news.

 

1. AfterMAc's drive is good (tested on my SE), but the IIfx just gives me a disk with an X when I plug it in and try to boot from a disk (I tried with both disk slots). I didn't feel the motor move like I did when it was plugged into the SE.

2. I also tried to boot from the hard drive the was in my SE (it had System 6.0.8), also a no go. I didn't even hear it spin. I get a ? disk when I try.

 

I'm stumped now.

 

Tempest

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2. I also tried to boot from the hard drive the was in my SE (it had System 6.0.8), also a no go. I didn't even hear it spin.

AHA!

 

Your +12V is bad! We now have a much more narrow set of possible problems.

 

There is probably a problem with your power supply. Try unplugging the power supply from the logic board and reconnecting it. (There is a chance that this connection is just dirty.)

 

Do you have a volt meter, or multimeter with voltage setting? We can tell you how to use this to test your power supply.

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How to test the power supply:

 

1. Turn on the Mac IIfx.

2. Set your volt meter to 20V range DC

3. Touch the black probe to a pin of the power supply connector that is connected to a black wire. Hold this probe here for each test.

4. Now touch the red probe to pins leading to each of the following colors to test:

 

Red -> Should be +5V (We know this one is good.)

Blue -> Should be -12V

Yellow -> Should be +12V (THIS ONE is probably bad.)

 

These steps will just verify that the problem is definitely the power supply.

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Ok I can try this tonight. What do you mean by this though? The black wire?

 

3. Touch the black probe to a pin of the power supply connector that is connected to a black wire. Hold this probe here for each test.

 

So do I have the wall plug plugged into the power supply and on when I do this?

 

Tempest

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Your +12V is bad! We now have a much more narrow set of possible problems.

 

There is probably a problem with your power supply. Try unplugging the power supply from the logic board and reconnecting it. (There is a chance that this connection is just dirty.)

 

Do you have a volt meter, or multimeter with voltage setting? We can tell you how to use this to test your power supply.

 

Yea I suspected as much on page one :scrambled: seemed simpler to just test the power than rip apart 2 machines swap parts out etc etc etc but whatever, were back on track now

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have any clue what voltages the power supply is putting out
Yea I suspected as much on page one :scrambled: seemed simpler to just test the power than rip apart 2 machines swap parts out etc etc etc but whatever, were back on track now

Yep yep, I see that now. That would have been a quick easy test.

 

So do I have the wall plug plugged into the power supply and on when I do this?

Yes, the Mac needs to be plugged in and powered on to do this.

 

Ok I can try this tonight. What do you mean by this though? The black wire?

There are several black wires in the power supply connector. You can use any one of them. With the Mac running, touch your volt meter to the exposed metal areas that connect to each respective wire color. From any black wire to any red wire should read +5V. Verify this to make sure you're doing it right (we know +5V is working), then check the yellow wire, which should be +12V.

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whatever the answer is don't toss the original, its issue could just be a leaky cap or burned out regulator, which can be pretty easily repaired by someone trained and safe while working on power supplies

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So what's the fix to something like this? Complete replacement of the power supply?

 

Tempest

That would certainly work. There are people on this board including myself who would like to try to fix it, but depending on who you send it to and what's wrong, it may not get fixed, or it may take more time than expected to figure out what's wrong. If I were you, I would ask in the trading post to find someone to fix it, and get general quotes on shipping, fixing it, etc.

 

Another option would be to get a working power supply and then sell your bad one to one of us. This could also be facilitated in the trading post. I'd say that's a better option, possibly less expensive too. No risk of expensive labor or needing strange parts. You know you'll have a good power supply. You pay shipping only one way. etc.

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So what's the fix to something like this? Complete replacement of the power supply?

 

Tempest

That would certainly work. There are people on this board including myself who would like to try to fix it, but depending on who you send it to and what's wrong, it may not get fixed, or it may take more time than expected to figure out what's wrong. If I were you, I would ask in the trading post to find someone to fix it, and get general quotes on shipping, fixing it, etc.

 

Another option would be to get a working power supply and then sell your bad one to one of us. This could also be facilitated in the trading post. I'd say that's a better option, possibly less expensive too. No risk of expensive labor or needing strange parts. You know you'll have a good power supply. You pay shipping only one way. etc.

 

I would agree with that. The cost of finding another powersupply or Mac II, is probably less than having someone fix it. Does the guy you got the IIfx from still have any Mac II's?

 

Then there is the benefit of selling your non-working PS... even if it's for the cost of shipping... it keeps a potential replacement part from being trashed. We all know ho scarce parts are getting these days.

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Does the guy you got the IIfx from still have any Mac II's?

Yeah he had two Mac II's and another IIfx. Are we sure the Mac II power supply is compatible with the IIfx? I thought the IIfx one was different (a variable speed fan or something).

 

Tempest

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Does the guy you got the IIfx from still have any Mac II's?

Yeah he had two Mac II's and another IIfx. Are we sure the Mac II power supply is compatible with the IIfx? I thought the IIfx one was different (a variable speed fan or something).

 

Tempest

 

Yup, it's compatible... it just won't have the variable speed fan (ie. single speed). Apple's upgrade path from a Mac II to a IIfx was a motherboard replacement and did NOT include a power supply. All of the voltage outputs are the same.

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I got a working power supply from a dead IIfx and it is giving the proper voltages. Unfortunately I'm still not getting any disk or HD activity. However I took a closer look at the board I think I may have discovered the problem. The trace on the top of the board on the left side that goes from the capacitor(?) at C45 to the spot below the second Nubus slot labeled FD15 (between zones N2 and K2) is completely burned out. It looks like it took a hit or something in the past. I'm not sure what this trace connects, but I'm guessing it's needed since it seems to come from the power supply.

 

I think at this point I'm SOL unless there's an easy way to repair such a thing. As a consolation though I got two nice looking Mac II's from the guy (for parts in case this power supply was also bad), another video card, and another full set of IIfx memory. So I guess even if this IIfx is dead I can at least make my money back selling the memory. A Mac II isn't too bad for a gaming machine I suppose. At least not for the stuff I want to play.

 

Tempest

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I got a working power supply from a dead IIfx and it is giving the proper voltages. Unfortunately I'm still not getting any disk or HD activity. However I took a closer look at the board I think I may have discovered the problem. The trace on the top of the board on the left side that goes from the capacitor(?) at C45 to the spot below the second Nubus slot labeled FD15 (between zones N2 and K2) is completely burned out. It looks like it took a hit or something in the past. I'm not sure what this trace connects, but I'm guessing it's needed since it seems to come from the power supply.

 

I think at this point I'm SOL unless there's an easy way to repair such a thing. As a consolation though I got two nice looking Mac II's from the guy (for parts in case this power supply was also bad), another video card, and another full set of IIfx memory. So I guess even if this IIfx is dead I can at least make my money back selling the memory. A Mac II isn't too bad for a gaming machine I suppose. At least not for the stuff I want to play.

 

Tempest

 

That sucks...

 

The Mac II had a variable speed fan.

 

The Mac II and IIx power supply a single speed fan. The IIfx has a variable speed.

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