okenido
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Why 80 pin IDE cable fried my Pi

Mon Jun 03, 2019 1:09 pm

Hello,

I know, NOW, that 80 wires IDE cables have pins 2, 19, 22, 24, 26, 30, 34 and 40 shorted together. Misleading design in my opinion...

Image

But even knowing that, I'm not sure WHY it fried my PI.

I provide 5V to pins 2 and 4, and they have been shorted to ground via pin 30 in the IDE cable itself. My power supply entered in security/recovery mode because of the short, but even if it may be slow to react, all current (or like 99.9% of it) should be flowing through the easiest path, which is the direct 5V - GND short which is nearly zero ohm resistance... thus preserving the Pi from being destroyed. Am i wrong here ?

Interestingly enough, my Pi is only partially fried - it would crash very easily and some GPIOs doesn't work anymore.
Last edited by okenido on Mon Jun 03, 2019 1:46 pm, edited 1 time in total.

W. H. Heydt
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Re: Why 80 pin IDE cable fried my Pi

Mon Jun 03, 2019 1:35 pm

Have you given the polyfuse time to recover?

As for the cable... It's designed for a late version of the PATA HDD interface specification, and--thus--NOT designed for use with a Pi. There is nothing "stupid" about the design. It would work just fine if used for its intended purpose.

LTolledo
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Re: Why 80 pin IDE cable fried my Pi

Mon Jun 03, 2019 1:41 pm

That cable WAS DESIGNED and INTENDED FOR USE with IDE drives and NOT FOR THE RPi GPIO.

It was your fault for using it, that fried your RPi, not the fault of the designer of the cable.

saw this in one article:
"....somebody put raw eggs in a microwave oven and it exploded upon turning on....causing injury, and its the fault of the microwave oven inventor?...."
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okenido
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Re: Why 80 pin IDE cable fried my Pi

Mon Jun 03, 2019 1:46 pm

well, no problem with that, but creating interconnections in a cable with separate pins is misleading in my opinion, such things should be done on the board so the cables stays as standard as possible... but okay !

wildfire
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Re: Why 80 pin IDE cable fried my Pi

Mon Jun 03, 2019 1:49 pm

With EIDE drives the cables had to be shielded to prevent data corruption, these cables were never meant for any other use than EIDE/PATA hard drives.
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LTolledo
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Re: Why 80 pin IDE cable fried my Pi

Mon Jun 03, 2019 1:50 pm

If you can still boot up and use your RPi , without using the GPIO headers anymore then there is still some good use for your RPi....you're still lucky!

and better get a "spare" RPi just in case.....
"Don't come to me with 'issues' for I don't know how to deal with those
Come to me with 'problems' and I'll help you find solutions"

Some people be like:
"Help me! Am drowning! But dont you dare touch me nor come near me!"

okenido
Posts: 57
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Re: Why 80 pin IDE cable fried my Pi

Mon Jun 03, 2019 1:54 pm

LTolledo wrote:
Mon Jun 03, 2019 1:41 pm
That cable WAS DESIGNED and INTENDED FOR USE with IDE drives and NOT FOR THE RPi GPIO.

It was your fault for using it, that fried your RPi, not the fault of the designer of the cable.

saw this in one article:
"....somebody put raw eggs in a microwave oven and it exploded upon turning on....causing injury, and its the fault of the microwave oven inventor?...."
your comparison is wrong.

here you have a cable that physically looks like it's straight wires connecting each pin from both connectors, but it isn't. It's more like seeing an unknown fruit looking like an apple, eating eat and getting ill because it wasn't an apple !

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PeterO
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Re: Why 80 pin IDE cable fried my Pi

Mon Jun 03, 2019 1:57 pm

okenido wrote:
Mon Jun 03, 2019 1:54 pm
LTolledo wrote:
Mon Jun 03, 2019 1:41 pm
That cable WAS DESIGNED and INTENDED FOR USE with IDE drives and NOT FOR THE RPi GPIO.

It was your fault for using it, that fried your RPi, not the fault of the designer of the cable.

saw this in one article:
"....somebody put raw eggs in a microwave oven and it exploded upon turning on....causing injury, and its the fault of the microwave oven inventor?...."
your comparison is wrong.

here you have a cable that physically looks like it's straight wires connecting each pin from both connectors, but it isn't. It's more like seeing an unknown fruit looking like an apple, eating eat and getting ill because it wasn't an apple !
No, because you could have easily verified how the pins were wired before you pluged it in.

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Ernst
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Re: Why 80 pin IDE cable fried my Pi

Mon Jun 03, 2019 2:00 pm

okenido wrote:
Mon Jun 03, 2019 1:54 pm
LTolledo wrote:
Mon Jun 03, 2019 1:41 pm
That cable WAS DESIGNED and INTENDED FOR USE with IDE drives and NOT FOR THE RPi GPIO.

It was your fault for using it, that fried your RPi, not the fault of the designer of the cable.

saw this in one article:
"....somebody put raw eggs in a microwave oven and it exploded upon turning on....causing injury, and its the fault of the microwave oven inventor?...."
your comparison is wrong.

here you have a cable that physically looks like it's straight wires connecting each pin from both connectors, but it isn't. It's more like seeing an unknown fruit looking like an apple, eating eat and getting ill because it wasn't an apple !
The comparison is right.
You did not question why there are three plugs on the cable, one black, one grey and one blue.
You did not question why an 80 core ribbon cable has 40 pin connectors.
You did not question why it is called an 80 pin (?) IDE cable.

With a little bit of research you could have found this: viewtopic.php?t=85620#p606098

Apologies to Majongg, this what you should have read: viewtopic.php?p=665572#p665572
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fruitoftheloom
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Re: Why 80 pin IDE cable fried my Pi

Mon Jun 03, 2019 2:13 pm

okenido wrote:
Mon Jun 03, 2019 1:09 pm
Hello,

I know, NOW, that 80 wires IDE cables have pins 2, 19, 22, 24, 26, 30, 34 and 40 shorted together. Misleading design in my opinion...

Image

But even knowing that, I'm not sure WHY it fried my PI.

I provide 5V to pins 2 and 4, and they have been shorted to ground via pin 30 in the IDE cable itself. My power supply entered in security/recovery mode because of the short, but even if it may be slow to react, all current (or like 99.9% of it) should be flowing through the easiest path, which is the direct 5V - GND short which is nearly zero ohm resistance... thus preserving the Pi from being destroyed. Am i wrong here ?

Interestingly enough, my Pi is only partially fried - it would crash very easily and some GPIOs doesn't work anymore.

The Cables are sold for use with Hard Drives & Optical Drives, not as GPIO Cables, buyer beware !
Retired disgracefully.....
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mahjongg
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Re: Why 80 pin IDE cable fried my Pi

Mon Jun 03, 2019 2:26 pm

Not much the RPF can do to prevent this kind of stupid mistakes, but we do have an entry for it in the "common pitfalls sticky", viewtopic.php?f=91&t=83372&p=651745#p665572 called "the wrong flatcable".

In fact the real error that lead to this pitfall was that 40-pole IDE cables were initially designed with a flaw, in that for high speed signals you should have one ground return wire per signal wire, but the original 40-pole cable had just a few GND wires. The industry solution was to design a backward compatible cable that simply doubled the number of wires, and that connected all odd (or perhaps even) wires together, and connected them to the few pins with the GND signal, as long as you did not reverse the cable that worked, and no changes to the PCB's of either the motherboards, nor the drives was needed.

but yeah if you re-purpose such cables, and are not aware of the background and nature of such 80-wire cables then you can expect problems.

drgeoff
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Re: Why 80 pin IDE cable fried my Pi

Mon Jun 03, 2019 6:18 pm

When the 40 pin interface on IDE drives and motherboards was devised a 20 Mbyte drive would have been considered huge and transfer speeds were low. It was only much later that drive sizes and speeds had increased to the point that the high data rates on the cable gave rise to data corruption (through crosstalk) prompting the introduction of the 80 wire cable with its grounded shielding wires between data wires.

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