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IIfx Won't boot
- Thread starter Tempest
- Start date
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)
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)
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
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
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?
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.
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.
The Mac will almost certainly be able to boot from a hard drive, but it will not help fix the floppy drive problem.
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.
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.
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
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.
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
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
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.
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.
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.
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
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
Yep yep, I see that now. That would have been a quick easy test.
Yes, the Mac needs to be plugged in and powered on to do this.
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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