Mellanox/EMC SX6012 - Revival Attempt

RageBone

Active Member
Jul 11, 2017
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exactly what necr said, i swear i have seen an error message exactly like that in one of the first and shorter console outputs that you have shown.

The reason for that is most likely an issue with one or more voltage rails.

To reiterate, Stuff does not just take 12v from the PSU.
SOCs, CPUs, GPUs take a lot of different voltages.

Most common are: 5V and 3.3V with Stand-By variants that are always on, so that the thing can ron on something low poer and then detect the power-button and turn on.
And 1.5V or 1.2V for DDR variants,
1V Vcore for the actual Switch "core"
And possibly other Perifery stuff, 1.8V PLL, what ever.
Many different voltages.

AS far as i could read the labels in your pictures / videos beside the green LEDs, for example with the blinking one that is not readable to me,
it looks like that is indicating the main 12V rail being wonky and since everything else gets created from there, nothing worked.

In later videos and pictures, still not readable to me, shoddy stuff honestly, it looks like you are still missing some of those needed voltages.
I can't tell you exactly which and how many because i don't have such a switch anymore and i can't honestly read and see stuff in anything you showed us so far.

My best bet currently is that you had a dead cap short the main 12v rail which caused that wonkyness, prolonged torture of that cap then blew that one up that its not shorting anymore and not you have a second issue of possibly VCORE not turning on and hence keeping the switch chip off.

excuse the rambly style, but i'm frustrated with your lack of cooperation so far.
 
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gb00s

Active Member
Jul 25, 2018
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... excuse the rambly style, but i'm frustrated with your lack of cooperation so far.
No worries if I need tissues, I will let you know. My problem is without a diagram I don't know where to measure the necessary parameters. The descriptions on the board are not helpful for me either. I understand and I will make some pictures as you requested.
 

RageBone

Active Member
Jul 11, 2017
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My problem is without a diagram I don't know where to measure the necessary parameters. The descriptions on the board are not helpful for me either. I understand and I will make some pictures as you requested.
Yes exactly.
There are things that "experienced" "technikitans" can swing along though, so those many many detailed and high res pictures would help with that a lot!
Looking forward to those
 
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RageBone

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Jul 11, 2017
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well, since you did not provide pictures yet, i got bored and looked at your videos again.

If i wanted, i could read the stuff beside the LEDs.

And wonder oh wonder, those LEDs are labled "Voltage PG" and "PG" very likely means "POWER GOOD".
Usually a logic signal to indicate that the voltage regulation is enabled and working as it shood.
= > Good Power ...
Lit up are:
3.3V AUX PG
VCORE PG
1.8?V PG
Not Lit up:
5V PG
3.3V_SX PG

So you have 100% an issue with the powerdelivery on the switch PCB.
Those two aren't necessarily dead, just, those rails missing is not good and for sure causes your switch to not work.
Just why they aren't working is now the question and again, they don't need to be dead, it could be something "upstream".

Ubiquity switches for instance run on 24V and more, and have a Buck-Converter to get that down to 12V for some rails like 1.5V MEM and 1V Core.
So if you don't have those two, could be because the 12V Buck died, and you would be wrong to blame MEM and Vcore.

Understood?

Pictures of the board please.
Befoer you scream that you have no idea where what is, i have no idea either, unless i can see stuff with my eyes and narrow it down a bit.
We would also initially be looking for irregularities like schmoo and burned or ripped stuff.
So, even if you have no idea, PLEASE, PLEASE make a few hole board and deatil pictures, there is nothin on the web i could find and do that for you.


Or just put it in a ****ing package and send it to me. Could use a SX6012 myself.
 

gb00s

Active Member
Jul 25, 2018
332
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Malta
Will prepare pictures. Just have to get it to my work for good light. Thanks.

shipping? Please tell me you are not from US?!