what makes a ferrite choke smoke

[klem]

i got a x79 extreme6 that started smoking on the left choke above the 24-pin connector its air cooled e5-4607 cpu 6870x2 card tx750 psu, psu, card still works tested on a p45

[parsec]

Re: what makes a ferrite choke smoke

Given the location of the choke, that would be part of the voltage regulation for the memory on the X79 board.

Regarding why it smoked, memory voltage regulators systems normally don't fail. Rarely if ever any heat sinks on the VR transistors since RAM does not use much power.

Did you have the memory voltage set very high with all the DIMM slots in use? Or possibly a short circuit of the pins of the choke on the bottom of the board to the mother board tray. Or possibly the 24 pin power connector's pins right next to those chokes were out of place for some reason. It will take some investigation to find out what happened, which could reveal nothing obvious. The choke itself could have just failed, a semi-defective part that took a while to fail. Might also be a PSU problem. Or maybe a memory stick not seated correctly.

I assume the board won't boot anymore? No reason for the video card to fail if the mother board memory VRM system fails.

[bahram_alinezhad]

Re: what makes a ferrite choke smoke

It looks smoked even on its asrock webpage:

http://www.asrock.com/mb/photo/X79%20Extreme6%28L1%29.jpg

[klem]

Re: what makes a ferrite choke smoke

Given the location of the choke, that would be part of the voltage regulation for the memory on the X79 board.

Regarding why it smoked, memory voltage regulators systems normally don't fail. Rarely if ever any heat sinks on the VR transistors since RAM does not use much power.

Did you have the memory voltage set very high with all the DIMM slots in use? Or possibly a short circuit of the pins of the choke on the bottom of the board to the mother board tray. Or possibly the 24 pin power connector's pins right next to those chokes were out of place for some reason. It will take some investigation to find out what happened, which could reveal nothing obvious. The choke itself could have just failed, a semi-defective part that took a while to fail. Might also be a PSU problem. Or maybe a memory stick not seated correctly.

I assume the board won't boot anymore? No reason for the video card to fail if the mother board memory VRM system fails.

voltage wasnt amped, i'm inspecting the memory, only had 3 slots in use on the left ,i tried 3 times after it shut down and i smell it (my side panel is always off) i took the board out the case and place it on a glass table and tested, pins 13-16 (3.3v,-12,common) are connected to both 1r0 chokes i traced it from the back, i got soldering skills just wanna troubleshoot which components to swap

[parsec]

Re: what makes a ferrite choke smoke

voltage wasnt amped, i'm inspecting the memory, only had 3 slots in use on the left ,i tried 3 times after it shut down and i smell it (my side panel is always off) i took the board out the case and place it on a glass table and tested, pins 13-16 (3.3v,-12,common) are connected to both 1r0 chokes i traced it from the back, i got soldering skills just wanna troubleshoot which components to swap

The -12V rail on a PC PSU is not used by any modern mother board like an X79, who knows why there is continuity there.

A fried inductor might not just be a randomly failed one, it may have been caused by something else. If the inductor died, think about the tiny surface mount parts all around it, did they survive?

It looks like there is a voltage regulator stage for each of the two DIMM slot sets, left and right. The parts layout is different, but I see common parts, two rectangular inductors, one square inductor, four capacitors, and four voltage regulator chips, with four legs each.

Anyway, good luck working on your board.

[klem]

Re: what makes a ferrite choke smoke

The -12V rail on a PC PSU is not used by any modern mother board like an X79, who knows why there is continuity there.

A fried inductor might not just be a randomly failed one, it may have been caused by something else. If the inductor died, think about the tiny surface mount parts all around it, did they survive?

It looks like there is a voltage regulator stage for each of the two DIMM slot sets, left and right. The parts layout is different, but I see common parts, two rectangular inductors, one square inductor, four capacitors, and four voltage regulator chips, with four legs each.

Anyway, good luck working on your board.

i checked for pins touching together on all slots including pci/e usb sata etc. and nothing it's still like new it even has that out-of-the-box smell

i made a mistake labeling -12v was to the choke it was 3.3v 3.3v common, 2 surface mount pieces underneath the left cap under the choke next to the right dimm slots above the 24pin connector doesnt have that same "condition" look like the other ones i tested the top 3.3v and it gave a short beep on my multimeter but the common and 3.3v in the middle gave a steady beep and says shorted i test the other side since you mention the same setup all had short beeps which i'm guessing good

[parsec]

Re: what makes a ferrite choke smoke

i checked for pins touching together on all slots including pci/e usb sata etc. and nothing it's still like new it even has that out-of-the-box smell

i made a mistake labeling -12v was to the choke it was 3.3v 3.3v common, 2 surface mount pieces underneath the left cap under the choke next to the right dimm slots above the 24pin connector doesnt have that same "condition" look like the other ones i tested the top 3.3v and it gave a short beep on my multimeter but the common and 3.3v in the middle gave a steady beep and says shorted i test the other side since you mention the same setup all had short beeps which i'm guessing good

That "-12V" thing makes sense now, had me wondering.

That one shorted surface mount part does not sound good. It is apparently possible to replace them with a special soldering iron tip with a U shape. But finding the value of the part if a resistor or cap, half the battle! Modern boards have hundreds of those tiny things, how they even assemble them is a miracle.

We should have known a board with DIMM slots on either side of the CPU socket would have memory power circuitry for each set of DIMMs. If possible, I would try checking the VM readings on the legs of the VR chips on both sides, to compare and hopefully check if the chips are Ok on the side with the bad choke.

Again, good luck with that, I'd like to know if you have success fixing it.