Olimex Support Forum

Microcontrollers => PIC => Topic started by: jschmied on July 18, 2013, 11:32:10 AM

Title: PCB Problem with PIC-P40
Post by: jschmied on July 18, 2013, 11:32:10 AM
Hi!

Two months ago I brought a PIC-P40 board. At the beginning there was no problem with it but four weeks ago the cristal oscillator stopped working. I thought the PIC had a problem and switched to the internal osc for testing. Shortly after there was a shortcut under C11. I had to remove C11 and replace it with a conventional one and scratch off the PCB under the old C11 because it was burned. The I noticed the boad draws to much current. Shortcut under C12. Testing all parts I noticed R2 was short cut too. So I removed it, cleand the board and replaced it with a new one.

Now everyting works a expected again.

Are there problems with the soldering process in the manufactoring recently?

Thanks!

Juergen
Title: Re: PCB Problem with PIC-P40
Post by: LubOlimex on July 18, 2013, 11:59:00 AM
Hello Juergen,

Are there problems with the soldering process in the manufactoring recently?

No. In fact quite the opposite - additional employees have been hired and we are in the process of installation of additional mounters.

Such short-circuited boards shouldn't leave the factory, however. Most of the tests include mounting the board (subject to test) on an extension board so each pin can be tested individually for any type of short-circuits.

PIC-P40, however, being a one-layer board is quite hard for testing and not all pins are tested thoroughly.

Best regards,
Lub/OLIMEX
Title: Re: PCB Problem with PIC-P40
Post by: jschmied on July 19, 2013, 02:39:52 PM
Hi!

I think the tests in factory wouldn't show this problems because these came after several weeks.
Maybe from solder paste ...

Best regards

Juergen
Title: Re: PCB Problem with PIC-P40
Post by: LubOlimex on July 19, 2013, 03:26:03 PM
Hey Juergen,

That indeed happens sometimes and is very hard to identify (since it can be identified only by observing the board).

During the soldering of some boards we use solder flux that might provide the grounds for such problem. This can be avoided if the board is properly washed but this is also quite subjective decision.

Such cold joints would be repaired for free as our warranty page says: https://www.olimex.com/wiki/GTC#Warranty (https://www.olimex.com/wiki/GTC#Warranty).

If you notice such hardware problems in future please report like you did now. This actually gets noticed and analyzed.

Best regards,
Lub/OLIMEX
Title: Re: PCB Problem with PIC-P40
Post by: jschmied on July 19, 2013, 04:38:07 PM
Hi!

Thanks for your response. I would have returned the board but I have put many of my own parts on it. So it's not worth to send back

Yours

Juegren