Olimex Support Forum

Microcontrollers => PIC => Topic started by: nabil on June 22, 2015, 08:49:12 AM

Title: Olimex PIC MAXI WEB over heating problem
Post by: nabil on June 22, 2015, 08:49:12 AM
Hello all,

I hope somebody can help me with this following problem:
I just received my Olimex PIC-Maxi Web last week,and after working on it for those few days i noticed that the PIC is over heating ,once i power the board the pic start to heat very fast in a crazy way.

I deleted my program and put back original but no thing change.
Can some body gave me advise please.

Thanks for any help.
Title: Re: Olimex PIC MAXI WEB over heating problem
Post by: nabil on June 23, 2015, 08:06:59 PM
Hey all,

i actually did farther testing on the board,during the 1 week i worked on it i was using only an analog input AN4/RA5,so i suspected that the problem may come from there since the sensor which was connected to this port is a 10V outpu,i did check the capacitor connected to this input and it's actually reading 19 Mega Ohm,could it the problem causing the overheating?
Title: Re: Olimex PIC MAXI WEB over heating problem
Post by: Stanimir5F on July 01, 2015, 04:59:23 PM
Hello nabil!

What is the input supply voltage? Is it in the interval 9-12V DC? If so - what is the power consumption with all LEDs on (also relays and the display backlight) and connected to LAN? In my case its 180mA when 12V are applied and 240mA when 9V. And during that time the PIC temperature is normal.

What do you mean by reading 19 mega ohm on the capacitor? Which capacitor? Because if you mean the one on RA5 (C45) it doesn't exist.

And if you give 10V input to the RA5(AN4) pin it's quite possible that you burn it. I'm not sure what is the maximum input voltage (you better check in the datasheet), but I'm pretty sure that 10 volts is too much.

Stan, Olimex
Title: Re: Olimex PIC MAXI WEB over heating problem
Post by: nabil on July 03, 2015, 09:11:02 PM
Hey,

first thank you a lot for your assistance.
I actually powered it with 12V with only LAN and LCD on and measuring 290mA.
i am not realy able to check component by component since i can't remove them.
The board itself work normally expect the overheating.
I also reading 3.3V on AN4 (which i set to analog input ).
Thanks again