Blew up 2 mining rigs with riser cables

[steve666]

I don't get it how people can manage to burn their rigs when going into mining stuff, you should learn more not only about that fantastic crypto world but also get some knowledge about electronics, power distribution and how does this all works together in theory and whats happening inside of all your machinery... I used to power my risers stright from the PSU without any capacitors, voltage regulators on boards just because its not even needed if you know what are you doing it's not needed at all, chinese just put this stuff on your boards to look nice and make bigger profit of worth nothing electronic components. To long cords, bad connectors and that all make higher resistance of circuit and failure at all, also ground loops, bad grounding which may cause inductions and amperage rise or falling rapidly.

all powered risered card have to be connected to main psu

is that true? I thought you could power the riser with the secondary psu as long as you also power the card with the secondary psu. You can't mix.

yeah you can't mix, no powered riser on second psu.

Powered risered cards on psu 1, non powered risered cards on psu 2

It doesn't even matter if you have efficient PSU, you could even use 12V car battery to power your risers or GPU's, it doesnt matter if the potentials are fine so it belongs on how you connect PSU's together and thats it.

 Thanks, Reagrds.

[leonix007]

I've been running a few mining rigs, which are basically just motherboards crammed with cards.

Due to heat problems, I've been looking to get some risers - and they finally arrived. I got 100 cm flexible USB cable risers, with SATA power. They look impressive 3 filter caps and a VRM on the riser board.

Anyway, the first thing I found was that no cards would be detected on the risers until I set the mobo BIOS to PCI-e v1.0.

So far, so good. So, one at a time, I transferred cards from mobo onto riser cables, and after a few false starts, I had 2 cards running on risers, and 1 on the mobo.

That's when I start to get adventurous, and connect a 4th card to a 1x PCI-e slot, and power it via a 2nd PSU. All the connections are double checked. The riser is in the slot the correct way round, etc.

Link the PSUs with a dual PSU adaptor, and power up.

*Sizzle* *Pop* *Crackle* <Burning smell> Cue sparks and smoke rising from the 1x PCI-e slot. The mobo is totally dead.

I recheck all the connections, and they are definitely correct.

Thinking I made a mistake, I decide to have another go.
This time, I connect directly a 1x PCI-e slot with a 4th card, after triple checking everything.

*Sizzle* *Crackle* Sparks. Another motherboard now dead.

I don't get it. I've built dozens of PCs in the past, and built a heap of mining rigs, albeit without risers. I've done dual PSU before.

What could have happened? What was cause sparks and sizzling and burn out a mobo. I've looked at the PCI-e riser design, and the power pins are not connected on the riser, so I don't see how a power surge or something could have come from the 2nd PSU back feeding the PCI-e slot.

Any ideas? Could it be a bad riser card? I've run a multimeter over it, and there don't appear to be any shorts or anything. I'm completely baffled.

I was thinking if you put your riser connection into PCI-e slot "Backwards", then it sure burnt it.

see this thread, not sure if it is, and might help in case

https://bitcointalk.org/index.php?topic=1983900.0

[Phantoms001]

I've been running a few mining rigs, which are basically just motherboards crammed with cards.

Due to heat problems, I've been looking to get some risers - and they finally arrived. I got 100 cm flexible USB cable risers, with SATA power. They look impressive 3 filter caps and a VRM on the riser board.

Anyway, the first thing I found was that no cards would be detected on the risers until I set the mobo BIOS to PCI-e v1.0.

So far, so good. So, one at a time, I transferred cards from mobo onto riser cables, and after a few false starts, I had 2 cards running on risers, and 1 on the mobo.

That's when I start to get adventurous, and connect a 4th card to a 1x PCI-e slot, and power it via a 2nd PSU. All the connections are double checked. The riser is in the slot the correct way round, etc.

Link the PSUs with a dual PSU adaptor, and power up.

*Sizzle* *Pop* *Crackle* <Burning smell> Cue sparks and smoke rising from the 1x PCI-e slot. The mobo is totally dead.

I recheck all the connections, and they are definitely correct.

Thinking I made a mistake, I decide to have another go.
This time, I connect directly a 1x PCI-e slot with a 4th card, after triple checking everything.

*Sizzle* *Crackle* Sparks. Another motherboard now dead.

I don't get it. I've built dozens of PCs in the past, and built a heap of mining rigs, albeit without risers. I've done dual PSU before.

What could have happened? What was cause sparks and sizzling and burn out a mobo. I've looked at the PCI-e riser design, and the power pins are not connected on the riser, so I don't see how a power surge or something could have come from the 2nd PSU back feeding the PCI-e slot.

Any ideas? Could it be a bad riser card? I've run a multimeter over it, and there don't appear to be any shorts or anything. I'm completely baffled.

I was thinking if you put your riser connection into PCI-e slot "Backwards", then it sure burnt it.

see this thread, not sure if it is, and might help in case

https://bitcointalk.org/index.php?topic=1983900.0

I agree, while I don't mix my riser power with 2 PSUs (I use 1 PSU for the board and all risers, the second just to power cards) I do know people that do mix the PSUs and their systems don't fry (why take a chance). 

It sure sounds like a riser put in backwards. 

[GeePeeU]

Try downgrading your system a bit. Follow KISS. (Keep it simple, stupid.)

Maybe start with a dual-on board- system, Using 1 PSU, then add risers/GPUs 1 by 1.

This might help you pinpoint where the fuck up is happening. But might not prevent you from doing it again. lol

[yobigd20]

I use 1 PSU for the board and all risers, the second just to power cards

^^^ This is a perfect example of how to start a fire either by crossing voltages or one psu crapping out while the other is still on.

*NEVER* power the riser and gpu from different psu's.

*ALWAYS* power the riser and gpu from the same psu.

[QuintLeo]

You had too much draw on your board. Do you really have 100cm(3 feet) long risers?

If they are actually that long, your GPUs would pull too hard and that's why you had a burnout.

 The length of the USB cable linking the riser to the "shortie board" that connects to the motherboard DOES NOT AFFECT THE POWER DRAW.

 That is NOT the issue at all.

 Backwards riser - possible but that more likely would cause the system to not power up at all.

 I'm more inclined to think there is an issue with the "add second PSU" adapter - one reason I like the B250 Mining Pro 19-slot MB as it has that part built into the MB and common-links their grounds the easy AND HARD TO MESS UP way.

[RIGED]

i killed 2 Asrock H110 BTC Pro because of crap soldering on risers

after checking the whole rig to the point of mental exhaustion and throwing in the towel, i started to check the soldering points on the riser components and sure enough i found 2 pieces (from the same batch) that had fused solder points, after replacing them and buying a third mobo problem solved

moral of the story is dont trust non quality certified equipment and at least do a visual inspect before use

[steve666]

I use 1 PSU for the board and all risers, the second just to power cards

^^^ This is a perfect example of how to start a fire either by crossing voltages or one psu crapping out while the other is still on.

*NEVER* power the riser and gpu from different psu's.

*ALWAYS* power the riser and gpu from the same psu.

Nothing will happen because there is no potential differences, and however if there will occur a lack of power on some components, system will shut itself down immediately... Also nothing will happen if you lose powering on one of PSU - it will cause the same.

I had many times back to my mining rigs to see that the motherboard is not powered due to PSU failure but the orher one is running still powering risers or GPU's external input or conversely - the cards were not powered but the mobo (system) was running with black screen, but after reboot it was everything OK anyway.

Guys, come on these are not 80's electronics, I know it is chinese crap done for $10 but we still have some protective circuit inside of it.

Regards

[64dimensions]

One other note: on rig start up sometimes you may forget to run whatever S/W you are using to setup the TDP. This is especially important if you are operating 1080ti's and accidentally forget this step and start at 100% TDP and your rig is laid out for say 65%.

[shubaduba]

One other note: on rig start up sometimes you may forget to run whatever S/W you are using to setup the TDP. This is especially important if you are operating 1080ti's and accidentally forget this step and start at 100% TDP and your rig is laid out for say 65%.

I have no problems with 8x1080ti rig starting and running at 100% or even 110% TDP.
If you mean that if the rig is not cooled enough for running at high TDP, then GPUs will halt upon reaching 94C degrees or whatever temp limit was set.

[QuintLeo]

One other note: on rig start up sometimes you may forget to run whatever S/W you are using to setup the TDP. This is especially important if you are operating 1080ti's and accidentally forget this step and start at 100% TDP and your rig is laid out for say 65%.

 Easy to set up LINUX to automatically and reliably set your TDP as part of the bootup process.

 Windows - well, I mostly like Afterburner but it DOES occasionally lose track of settings for one or more cards....