Disabling wifi was always a good idea.
Hard line is far more reliable in general, rather than suffer a wifi drop at a bad moment (submitting a difficulty 64 hash). It also uses less memory.
Topic: Avalon ASIC users thread - page 173. (Read 438387 times)
Bump senseless's question.
If F1 is the power line to USB-A1... if nothing is plugged into USB-A1, how is this causing too much power to be drawn from the control board? Perhaps that is why Bitsyncom said "this is fine"?
If F1 is the power line to USB-A1... if nothing is plugged into USB-A1, how is this causing too much power to be drawn from the control board? Perhaps that is why Bitsyncom said "this is fine"?
The description that the TP-LINK is "drawing too much power" is actually incorrect.
The USB hub chip does not overheat because the TP-LINK draws too much power. The TP-LINK is powered via a 5V line that does not even come from the USB hub chip.
Instead, the hub chip overheats because of a flaw in the control unit v1.5 design which I found while poring over the schematics: they accidentally feed 5V to one of the pins of the chip instead of 3.3V. This overvoltage is what causes the chip to overheat. I pinged Yifu who confirmed it, and I filed a bug quoting his response: https://github.com/BitSyncom/avalon-ref/issues/5
Removing the fuse F1 merely cuts voltage to this pin. It leaves the USB type B port (which powers the TP-LINK) completely unaffected.
The USB hub chip does not overheat because the TP-LINK draws too much power. The TP-LINK is powered via a 5V line that does not even come from the USB hub chip.
Instead, the hub chip overheats because of a flaw in the control unit v1.5 design which I found while poring over the schematics: they accidentally feed 5V to one of the pins of the chip instead of 3.3V. This overvoltage is what causes the chip to overheat. I pinged Yifu who confirmed it, and I filed a bug quoting his response: https://github.com/BitSyncom/avalon-ref/issues/5
Removing the fuse F1 merely cuts voltage to this pin. It leaves the USB type B port (which powers the TP-LINK) completely unaffected.
From the link to github I read BitSyncom answer where he says: "Thanks, this is true, will cause the chip to be about ~20C higher than avg, which is still fine [...]"
So, adding a small heat sink could be a "simpler" solution, isn't it?
It seems that removing F1 is the correct thing to do, but it can be done, not it HAS to be done.
Am I reading this correctly?
spiccioli
If I were you I will ask them to de-solder a test SMT component from an unused hardware first before letting them work on Avalon controller.
I have a dead 5870 lying around... I'll ask them to do a test on it first, good idea!
spiccioli
If I were you I will ask them to de-solder a test SMT component from an unused hardware first before letting them work on Avalon controller.
I have a dead 5870 lying around... I'll ask them to do a test on it first, good idea!
spiccioli
Now,
let's see, how difficult can it be to desolder F1 if someone has never used a solder in his whole life?
If I try such operation, do I really risk to destroy the control board?
Is there something I (we) really need to know before starting to desolder F1?
spiccioli
let's see, how difficult can it be to desolder F1 if someone has never used a solder in his whole life?
If I try such operation, do I really risk to destroy the control board?
Is there something I (we) really need to know before starting to desolder F1?
spiccioli
my tips.
a) Use a weller soldering station or equivalent. Set temp to 75% of max range or more.
b) use rosin cored solder on both sides of the fuse and alternate every 0.5 seconds and the component will slip off. Flux / rosin is must or else solder may spill to other components and cause a bridge + frustrations.
c) practice on a dead video card / modem / etc
Hi goxed,
thanks a lot, I've just found a pc shop which does little repairs which will desolder it for me
spiccioli
If I were you I will ask them to de-solder a test SMT component from an unused hardware first before letting them work on Avalon controller.
Now,
let's see, how difficult can it be to desolder F1 if someone has never used a solder in his whole life?
If I try such operation, do I really risk to destroy the control board?
Is there something I (we) really need to know before starting to desolder F1?
spiccioli
let's see, how difficult can it be to desolder F1 if someone has never used a solder in his whole life?
If I try such operation, do I really risk to destroy the control board?
Is there something I (we) really need to know before starting to desolder F1?
spiccioli
my tips.
a) Use a weller soldering station or equivalent. Set temp to 75% of max range or more.
b) use rosin cored solder on both sides of the fuse and alternate every 0.5 seconds and the component will slip off. Flux / rosin is must or else solder may spill to other components and cause a bridge + frustrations.
c) practice on a dead video card / modem / etc
Hi goxed,
thanks a lot, I've just found a pc shop which does little repairs which will desolder it for me
spiccioli
The description that the TP-LINK is "drawing too much power" is actually incorrect.
The USB hub chip does not overheat because the TP-LINK draws too much power. The TP-LINK is powered via a 5V line that does not even come from the USB hub chip.
Instead, the hub chip overheats because of a flaw in the control unit v1.5 design which I found while poring over the schematics: they accidentally feed 5V to one of the pins of the chip instead of 3.3V. This overvoltage is what causes the chip to overheat. I pinged Yifu who confirmed it, and I filed a bug quoting his response: https://github.com/BitSyncom/avalon-ref/issues/5
Removing the fuse F1 merely cuts voltage to this pin. It leaves the USB type B port (which powers the TP-LINK) completely unaffected.
The USB hub chip does not overheat because the TP-LINK draws too much power. The TP-LINK is powered via a 5V line that does not even come from the USB hub chip.
Instead, the hub chip overheats because of a flaw in the control unit v1.5 design which I found while poring over the schematics: they accidentally feed 5V to one of the pins of the chip instead of 3.3V. This overvoltage is what causes the chip to overheat. I pinged Yifu who confirmed it, and I filed a bug quoting his response: https://github.com/BitSyncom/avalon-ref/issues/5
Removing the fuse F1 merely cuts voltage to this pin. It leaves the USB type B port (which powers the TP-LINK) completely unaffected.
Thanks +1. This needs to be rectified ASAP. Will report after fixing the pin today.
Now,
let's see, how difficult can it be to desolder F1 if someone has never used a solder in his whole life?
If I try such operation, do I really risk to destroy the control board?
Is there something I (we) really need to know before starting to desolder F1?
spiccioli
And will this void warranty (of any kind) given that this is actually a factory flaw user need to fix? let's see, how difficult can it be to desolder F1 if someone has never used a solder in his whole life?
If I try such operation, do I really risk to destroy the control board?
Is there something I (we) really need to know before starting to desolder F1?
spiccioli
Now,
let's see, how difficult can it be to desolder F1 if someone has never used a solder in his whole life?
If I try such operation, do I really risk to destroy the control board?
Is there something I (we) really need to know before starting to desolder F1?
spiccioli
let's see, how difficult can it be to desolder F1 if someone has never used a solder in his whole life?
If I try such operation, do I really risk to destroy the control board?
Is there something I (we) really need to know before starting to desolder F1?
spiccioli
my tips.
a) Use a weller soldering station or equivalent. Set temp to 75% of max range or more.
b) use rosin cored solder on both sides of the fuse and alternate every 0.5 seconds and the component will slip off. Flux / rosin is must or else solder may spill to other components and cause a bridge + frustrations.
c) practice on a dead video card / modem / etc
Now,
let's see, how difficult can it be to desolder F1 if someone has never used a solder in his whole life?
If I try such operation, do I really risk to destroy the control board?
Is there something I (we) really need to know before starting to desolder F1?
spiccioli
let's see, how difficult can it be to desolder F1 if someone has never used a solder in his whole life?
If I try such operation, do I really risk to destroy the control board?
Is there something I (we) really need to know before starting to desolder F1?
spiccioli
I want to change the fan on Avalon to a high CFM model, but I'm not sure the fan plug can provide enough current, the existing fan is drawing 1.3A maximum and I'm getting a 3.0A fan, will it cause overheat or burn some part on the controller unit?
I am not saying that disabling wifi won't help. There is definitely what seems to be a second problem, that is taken care of by disabling wifi, which is a good thing to do in addition to removing the fuse F1. I have a hunch that it is because there is no decoupling capacitor close to USB-B1 (C44 is too distant), and the power consumption of the TP-LINK with wifi enabled is very variable, causing ripple across the internal 5V rail of the control unit...
Or just to put usb powered hub get 5V for the hub from PSU - molex whatever and plug both TP-link and controller in it:)
and remove Fuse of course
And yes disable wireless (delete wifi modules) not because of power issues (solved with usb hub already) but to free about 10M of RAM
mrb,
thanks for the explanation, do you think that disabling wireless is enough to prevent overheating that chip and if I remove that fuse can I use wireless or is it better to disable wireless in any case?
spiccioli
thanks for the explanation, do you think that disabling wireless is enough to prevent overheating that chip and if I remove that fuse can I use wireless or is it better to disable wireless in any case?
spiccioli
I am not saying that disabling wifi won't help. There is definitely what seems to be a second problem, that is taken care of by disabling wifi, which is a good thing to do in addition to removing the fuse F1. I have a hunch that it is because there is no decoupling capacitor close to USB-B1 (C44 is too distant), and the power consumption of the TP-LINK with wifi enabled is very variable, causing ripple across the internal 5V rail of the control unit...
Thank you for the explanation. Another question that I haven't been able to find an answer for. Why does removing the fuse matter if there is nothing plugged into the port? Is it feeding a 3.3v on the usb-hub or the port itself? I would have thought there would be nothing flowing over that path if there is no completed circuit (usb cable plugged in), is that not correct?
(I can't see the PCB designs as I dont have altium viewer installed.. Their site seemed broken on the 3 browsers i tried to register with...)
I am not saying that disabling wifi won't help. There is definitely what seems to be a second problem, that is taken care of by disabling wifi, which is a good thing to do in addition to removing the fuse F1. I have a hunch that it is because there is no decoupling capacitor close to USB-B1 (C44 is too distant), and the power consumption of the TP-LINK with wifi enabled is very variable, causing ripple across the internal 5V rail of the control unit...
The new version of cgminer, with full direct USB support for Avalon is out:
https://bitcointalksearch.org/topic/m.2326320
Xiangfu will likely make new firmware for testing soon.
https://bitcointalksearch.org/topic/m.2326320
Xiangfu will likely make new firmware for testing soon.
So to better understand and be sure, the better thing to do is to remove the fuse, I've never used a solder in my life, so this is a BIG problem for me.
Otherwise I can just power off wireless ethernet and this is enough, isn't it?
From mrb description I'd say it is not enough, though.
spiccioli
edit: upon further reading, no, powering off wireless ethernet is not the correct thing to do, the problem is that 5V are fed to a pin which should receive 3V.
Otherwise I can just power off wireless ethernet and this is enough, isn't it?
From mrb description I'd say it is not enough, though.
spiccioli
edit: upon further reading, no, powering off wireless ethernet is not the correct thing to do, the problem is that 5V are fed to a pin which should receive 3V.
Looking closely at that fuse (F1), you can see the fuse (the squiggly line). It is encased in what looks like clear blue/green plastic. Perhaps so you can see it... it is a fuse after all. I am wondering if an exacto knife type blade could just slice through it, breaking the connection. Granted, you would have to be careful not to damage anything else... but I trust myself more to do that than to de-solder a component.
The description that the TP-LINK is "drawing too much power" is actually incorrect.
The USB hub chip does not overheat because the TP-LINK draws too much power. The TP-LINK is powered via a 5V line that does not even come from the USB hub chip.
The USB hub chip does not overheat because the TP-LINK draws too much power. The TP-LINK is powered via a 5V line that does not even come from the USB hub chip.
It was just a guess on my part I have no meter or the necessary tools on hand to find out for sure. I couldn't think of any other explanation on why my unit became stable after disabling the wifi. The only thing disabling the wifi is going to do is reduce EMF and power draw. I currently have the F1 in place and my unit has been mining solid for the last 12 hours without a reboot or issue after disabling the Wifi.
Jump to: