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Re: uc300eth - Overheating processor chip

PostPosted: Thu Feb 21, 2019 3:08 am
by Fretty
Hi Everyone! I'm back...
We did the experiment with only the power-supply and the Eth plugged in and the results is the same. After an hour the heat switches in.

He said he don't know if it was an original problem or not because the early experiment periods never went over an hour, until one day he decided to attempt a 3D project which catered for a period of 4hrs plus. It was at that time he discovered the problem.

I guess there is very little I can do about that now because I'm now the new owner of the CNC in question.
I recently bought it from him as is.
I guess I'll have to locate a new controller, if my projects are going to cross an hour in milling time.

Thanks you guys for all the assistance given.
Respectfully.

Fretty.

Re: uc300eth - Overheating processor chip

PostPosted: Thu Feb 21, 2019 3:35 am
by cncdrive
Then the only thing what is possibly causing this type of issue is ESD damage of the IC. It was probably touched uncarefully and so the electric charge from the human body damaged something inside the chip.
These chips like any others are ESD sensitive, they should be handled carefully.
In the factory we using ESD gloves and grounded ESD bracelets when we have to touch any boards or ICs etc. and the boards are shipped in ESD packing.

I can think that ESD damage as the only possibility, because even if some pins of the chip were damaged (e.g. due to overvoltages) and were in short circuit that would still not cause that high amount of heating and no I/Os of the chip are connected to the external world directly, so it is very unlikely that I/O damage of the chip causes this and so only ESD damage remains as the possible cause for the excessive heating.
However I have never seen a microcontroller to damage like this, but ofcourse the possibility is there and there is no other logical reason for this problem.
And anyways this chip is damaged for sure, so the chip should be replaced or the controller should be replaced to resolve the issue.

Re: uc300eth - Overheating processor chip

PostPosted: Thu Feb 21, 2019 11:03 pm
by Fretty
Thank you guys,
It was a pleasure. I'll keep this machine as is to do very short runs until I decide my next move.
I've 12 other machines operating with the basic parallel port system 10 years and counting they are not as smooth as the Uc300eth but they gets the work done.
I was about to do some upgrades but the shot down period has passed to get that change over done, so I'll have to wait until my next upgrade cycle.
Thanks again for your technical info.

Respectfully.
Fretty.

Re: uc300eth - Overheating processor chip

PostPosted: Thu Feb 21, 2019 11:58 pm
by cncdrive
The UC300ETH also gets the job done if it was not damaged.
Unfortunately damaged electronics usually does not work very well.

Re: uc300eth - Overheating processor chip

PostPosted: Fri Jun 14, 2019 1:25 am
by Fretty
Hi Rob and the whole cncdrive crew, how are you all?
I'm back to give you the good news, do you remember a few months back in February I had a overheating problem with my uc300eth controller?
Well the problem was solved sometime in early March.
I took the Board to a technician to have it checked, what he did was to use a soda can and make a funnel with a 1/8" nozzel, place it on his heat gun at high temp and kept it very close on the centre of the processor for about 10 sec. he then let it cool down for about an hour.

When I took it back home I was not expecting anything much but to my suprise its been working 24-0-7 since then with no problem. I decided to hold out and be sure it stand up before I break the good news.

So it seems like there was some kind of internal problem originally.

Ok guys thanks for all assistance given, fully appreaciated, Cheers.

Fretty.

Re: uc300eth - Overheating processor chip

PostPosted: Fri Jun 14, 2019 4:49 am
by A_Camera
Did you check the power supply? Not just the voltage but preferably also with an oscilloscope to check that the voltage is clean.

Re: uc300eth - Overheating processor chip

PostPosted: Fri Jun 14, 2019 12:31 pm
by 3d0g
That solution - reflowing the chip - would make perfect sense if it had a thermal pad underneath. To my knowledge, the PIC 33 series doesn't, however. Maybe the tech noticed a solder bridge or incomplete reflow on some pins.

Re: uc300eth - Overheating processor chip

PostPosted: Fri Jun 14, 2019 3:11 pm
by cncdrive
No, it does not have a thermal pad, it is in TQFP socket which does not have a thermal pad. No it is not a PIC33 series, but a PIC32MZ series.
Solder bridge is not really possible, it would be noticed by the AOI machine and the automatic tester we use.
However it might be possible that conductive material (e.g. metal chip.) fallen between IC pins. I mean it's a CNC creating metal chips. :)

Re: uc300eth - Overheating processor chip

PostPosted: Sun Jun 16, 2019 4:10 am
by Fretty
Hi guys! Thanks a lot, What ever it was it's working now, I truly do appreciate the valuable informations given, I am now seeing my investment at work.
My experience is just food for thought for those who may have similar problems in the future as an option.
Cheers to you all.
Fretty.