Some Core I7 5960X + X99 Motherboards Mysteriously Burning Up

An anonymous reader writes "Intel's Haswell-E Eight-Core CPU and X99 motherboards just debuted but it looks like there may be some early adoption troubles leading to the new, ultra-expensive X99 motherboards and processors burning up. Phoronix first ran a story about their X99 motherboard having a small flame and smoke when powering up for the first time and then Legit Reviews also ran an article about their motherboard going up in smoke for reasons unknown. The RAM, X99 motherboards, and power supplies were different in these two cases. Manufacturers are now investigating and in at least the case of LR their Core i7-5960X also fried in the process."

Comments

Re:Not just one mobo

[PopeRatzo]

"FPGAs use synchronous logic, so they pull power in spikes as the logic switches. If it took 9 months to realize there was a problem, you can probably make some small modifications to get it working reliably. Make sure the leads from the VRM are as fat as possible, preferably have it feed into full ground and power layers, and make sure no other traces are splitting those planes. Clock all three FPGAs from the same xtal, and use a delay gate or tune the length of the traces so the signal is skewed enough that the power spikes from each FPGA are not hitting simultaneously. Add plenty of decoupling caps on every power and ground pin. Make sure the caps have leads that are fat and short. It is better to have a physically small cap (0201 or 01005) in close than a bigger one further out. Good luck."

It's like Penthouse Forum for nerds.

Re: Not just one mobo

[DigiShaman]

Never -ever- cheap out on the PSU. You'll have to read the reviews, but make damn sure you get one with quality Japanese components.

If motherboards are using shit components these days, at least rely on clean and stable power to it.

Re:HCF

[CaptQuark]

I gather however that this is plain incompetence (Dunning-Kruger-Type) with regards to the voltage regulators. Switching voltage regulation is really hard to do right unless you over-engineer seriously. You can get all sorts of bizarre effects, including a puff of smoke.

I appreciate the irony of you mentioning the Dunning-Kruger syndrome with your statement. Switching voltage regulation has been around for over 30 years and isn't much of a mystery. Since the early motherboards started reducing voltages from 5v down to 3.3v (and below), every motherboard has had on-board voltage regulation. It's hard to believe that something as fundamental as a switching regulator would suddenly exceed the engineering skill of the motherboard designers.

~~

Re:Houston ...

[Ed_1024]

I was interested by the actions of the user of the motherboard on one of the linked articles. Initially this happened:

"The system came up, hung for a very short time and then powered off with a audible click of the Corsair AX860i power supply. If you have ever heard the loud click of the Over Current Protection (OCP) shutting down the PSU you know exactly what click I heard. Now when I press power button on the motherboard the system clicks after being on for a split second. I unplugged all the cables on the power supply and did the built-in self-check and it passed with flying colors. I still swapped out the PSU with a backup Corsair AX860i and the same click was to be heard. and it is doing the same thing (Corsair AX860i). After clearing the CMOS, removing the memory, SSD and video card the system still would not post. At that point in time I switched to a non-digital power supply (Corsair AX1200) and it did the same thing although this time the OCP took a little longer to kick in. There was some audible crackling noises, followed by some smoke near the CPU VRM heatsink. So, the heart shattering smell of burnt electronics filled the room..."

10/10 for investigative journalism but putting more and more juice into something that is continually tripping out the power supply is not going to have a happy ending. Maybe some of the $1,400-worth of motherboard and processor may have been salvageable if he had stopped at the first warning?

If the circuit breaker pops twice on a ring main at home, do you a) replace the circuit breaker with a bigger one, b) hold it in until smoke appears from behind the wall or c) do some serious investigation and/or call an electrician before putting the power back on?