Disk boot failure

[Ol Rattler]

Patrick, is there a notch in the black connector where it connects to the floppy drive .... if there is then you can only connect the cable to the floppy drive in one way so pin 1 is automatically correct. You also have a pic showing how it was originally connected, and this looks right to me .. note the twist in the cable ... as Dave says this has to be just behind the floppy like in your pic.

You have no way of knowing whether the connector is correctly installed on the controller side as you do not have the red stripe and there is not notch (see your pic below). Just try flipping the cable on the controller side therefore.

I flipped the cable on the controller side and got the same results. Floppy disk(s) fail. I then returned the cable back to it's correct orientation. What next?

 

[Ol Rattler]

I flipped the cable on the controller side and got the same results. Floppy disk(s) fail. I then returned the cable back to it's correct orientation. What next?

I could remove the floppy drive from the cabinet in order to get a better look at #1 position.

 

[Brian Todd]

Patrick, I just dug out one of my own floppy cable which does have the red stripe and the notch as shown in the pic below. If we compare my cable to the pic of your computer before you took it to bits, this means that pin 1 is the pin next to the power connector on your floppy drive assuming that the notch is oriented on the lower side of your floppy drive (which it seems to be from your pic in post #142). You can then trace this to your controller card and see if you have it correctly connected.

I assume you have the other end connected to "FDC connection" on the controller card?

 

[Ol Rattler]

Patrick, I just dug out one of my own floppy cable which does have the red stripe and the notch as shown in the pic below. If we compare my cable to the pic of your computer before you took it to bits, this means that pin 1 is the pin next to the power connector on your floppy drive assuming that the notch is oriented on the lower side of your floppy drive (which it seems to be from your pic in post #142). You can then trace this to your controller card and see if you have it correctly connected.

I assume you have the other end connected to "FDC connection" on the controller card?

Then both of my connections are correct. The red stripe on the cable end, at the controller, is connected next to pin #1. I can clearly see #1 position on the card. I then traced to red stripe all the back to floppy drive. Red stripe is next to power plug.

 

[Brian Todd]

Then both of my connections are correct. The red stripe on the cable end, at the controller, is connected next to pin #1. I can clearly see #1 position on the card. I then traced to red stripe all the back to floppy drive. Red stripe is next to power plug.

And to be clear ... you have connected the "twist" part to the floppy drive and the other end to the controller? There will be a third connector on the ribbon and this should not be connected to anything. Can you please make a pic of the way you have it connected so that we can visualise it? Thanks

 

[Ol Rattler]

And to be clear ... you have connected the "twist" part to the floppy drive and the other end to the controller? There will be a third connector on the ribbon and this should not be connected to anything. Can you please make a pic of the way you have it connected so that we can visualise it? Thanks

 

[Ol Rattler]

Yes, the twisted with red stripe connected to floppy drive, next to power. The other end
of the same cable with a black block in the middle of the cable is plugged into the controller. Middle cable block is not connected.

 

[Ol Rattler]

Yes, the twisted with red stripe connected to floppy drive, next to power. The other end
of the same cable with a black block in the middle of the cable is plugged into the controller. Middle cable block is not connected.

Should I unplug cd-rom power?

 

[Brian Todd]

No problem with leaving the CD Rom power in Patrick, and the floppy connector cable looks fine. When you boot up the computer, do you see the (green) LED light flash on the floppy drive? Also, if you insert a floppy does the LED come on and does the floppy drive make any noise? If the answer to both is no, then I suspect the floppy drive is not getting power or that something happened when you got the spark. Do you have a multimeter? If so, disconnect the power to the floppy, boot up the computer and measure how many volts you have on the floppy power connector (it is DC current).

@daver2 - any further ideas?

 

[daver2]

It is DC Voltage. Set the multimeter to read DC Volts and measure between the black and red wires (should be +5V) and between the black and yellow wires (should be +12V).

Brian,

You are suspecting what I am suspecting... No power somewhere.

Dave

 

[Brian Todd]

It is DC Voltage. Set the multimeter to read DC Volts and measure between the black and red wires (should be +5V) and between the black and yellow wires (should be +12V).

Brian,

You are suspecting what I am suspecting... No power somewhere.

Dave

Well spotted Dave ... I meant voltage not current! Thanks!

@patrick - as the CD Rom is also connected, please see if it will eject when the PC is powered up .. it is on the same power connector as your Floppy Drive...

 

[daver2]

I suppose the dumb question is: what is the manufacturer and make/model number of the floppy disk drive unit itself? We can then look up the manual for it to double-check the connections.

They look right to me though...

Dave

 

[Ol Rattler]

No problem with leaving the CD Rom power in Patrick, and the floppy connector cable looks fine. When you boot up the computer, do you see the (green) LED light flash on the floppy drive? Also, if you insert a floppy does the LED come on and does the floppy drive make any noise? If the answer to both is no, then I suspect the floppy drive is not getting power or that something happened when you got the spark. Do you have a multimeter? If so, disconnect the power to the floppy, boot up the computer and measure how many volts you have on the floppy power connector (it is DC current).

@daver2 - any further ideas?

No green light on floppy front, even after inserted disk. Gimmie a minute about multimeter.

No problem with leaving the CD Rom power in Patrick, and the floppy connector cable looks fine. When you boot up the computer, do you see the (green) LED light flash on the floppy drive? Also, if you insert a floppy does the LED come on and does the floppy drive make any noise? If the answer to both is no, then I suspect the floppy drive is not getting power or that something happened when you got the spark. Do you have a multimeter? If so, disconnect the power to the floppy, boot up the computer and measure how many volts you have on the floppy power connector (it is DC current).

@daver2 - any further ideas?

Blk/red=4 vdc
blk/yel=11 vdc
cd-rom eject, works.

 

[Ol Rattler]

I suppose the dumb question is: what is the manufacturer and make/model number of the floppy disk drive unit itself? We can then look up the manual for it to double-check the connections.

They look right to me though...

Dave

It'll take me a few minutes for extraction.

 

[Ol Rattler]

It'll take me a few minutes for extraction.

 

[Brian Todd]

Patrick, did you measure the 4V at the floppy connector or at the CD Rom connector? It would be good to confirm that the floppy is getting power - 4V sounds low to me, but maybe Dave can confirm if it is enough to drive the floppy disk. If the floppy is getting power and the LED light is not going on under any circumstances, then it is safe to assume that the floppy drive is dead. It should not be too hard to locate a replacement on Ebay, or maybe a fellow forum member can sell you one. First of all though, let's get confirmation from Dave that 4V is sufificient to drive the floppy.

What you could do in the meantime is to reconnect the CD Rom connector so that it is also connected to your interface card. Boot the system (using F1 to bypass floppy) and see if the CD Rom is recognised. This being the case, you can put the sound card and network cards back into the system and all should be well except the floppy.

 

[daver2]

+4V is too low. However, it is too low for the CD-ROM as well...

The +5V rail needs to be above +4.75 Volts.

However, it is also interesting that the +12V rail is also measuring +11V (1V low as well). This sort of indicates to me that your meter is reading low...

The fact that the CD-ROM drive is working correctly, and you do have approximately the correct voltages on the floppy connector implies that things are OK.

What I was thinking is that (when you attempted to connect the power to the floppy drive a while ago with the power ON and you got the spark) that you may have inadvertently attempted to plug the power connector on 'backwards'? This would have put +12V on the +5V rail of the floppy electronics and fried it...

I agree with Brian. Let's try and get the CD-ROM to work next and then put the motherboard cards back in to build up a working system (minus the floppy) and then buy a replacement floppy drive from eBay (or a local computer shop).

I have found some documentation on the Mitsumi D359T5 online and the implication is that you appear to have it cabled up correctly. Incidentally, pins 1 and 34 appear to be marked on the floppy PCB on the white silk screen next to the floppy signal connector.

Dave

 

[Ol Rattler]

Patrick, did you measure the 4V at the floppy connector or at the CD Rom connector? It would be good to confirm that the floppy is getting power - 4V sounds low to me, but maybe Dave can confirm if it is enough to drive the floppy disk. If the floppy is getting power and the LED light is not going on under any circumstances, then it is safe to assume that the floppy drive is dead. It should not be too hard to locate a replacement on Ebay, or maybe a fellow forum member can sell you one. First of all though, let's get confirmation from Dave that 4V is sufificient to drive the floppy.

What you could do in the meantime is to reconnect the CD Rom connector so that it is also connected to your interface card. Boot the system (using F1 to bypass floppy) and see if the CD Rom is recognised. This being the case, you can put the sound card and network cards back into the system and all should be well except the floppy.

Understood. I'm reinstalling floppy drive. Then get a +vdc reading for cd-rom. To be clear. The 40 pin cable from cd-rom goes to 40 pin position at silk screen 40/1 on the disk control card.

 

[Ol Rattler]

+4V is too low. However, it is too low for the CD-ROM as well...

The +5V rail needs to be above +4.75 Volts.

However, it is also interesting that the +12V rail is also measuring +11V (1V low as well). This sort of indicates to me that your meter is reading low...

The fact that the CD-ROM drive is working correctly, and you do have approximately the correct voltages on the floppy connector implies that things are OK.

What I was thinking is that (when you attempted to connect the power to the floppy drive a while ago with the power ON and you got the spark) that you may have inadvertently attempted to plug the power connector on 'backwards'? This would have put +12V on the +5V rail of the floppy electronics and fried it...

I agree with Brian. Let's try and get the CD-ROM to work next and then put the motherboard cards back in to build up a working system (minus the floppy) and then buy a replacement floppy drive from eBay (or a local computer shop).

I have found some documentation on the Mitsumi D359T5 online and the implication is that you appear to have it cabled up correctly. Incidentally, pins 1 and 34 appear to be marked on the floppy PCB on the white silk screen next to the floppy signal connector.

Dave

I'm getting a +vdc reading at the cd-rom power, as per Brian. Shall I leave floppy drive connected?

 

[daver2]

No. Disconnect the floppy drive (both signal and power) if it is not working.

That is a good question about the CD-ROM cable.

Can you remember how it was cabled originally?

Dave