Have you ever received a board with marks like these?

Other Hardware General Electronics
1

Hi,

I ordered a board and couldn't get it to work.
When I looked closer it seemed to have marks of previous usage, this is not how board leave the factory right?

To be clear, I have not touched or soldered on these pads myself.

If you have any thoughts on this please post.

Thanks.

=== EDIT ===
This is not an arduino but a LTE-M board that I ordered from a webshop, not from the original manufacturer. This webshop has a 'no questions asked' return policy and I wanted to check for some opinions before accusing them of sending me a faulty returned item.

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2

Looks like traces of something used during manufacturing, possibly in the solder mask or silkscreen steps - or a protective coating that's supposed to wash off of the pads, but didn't quite.

Nothing that would worry me, unless I was doing a project for NASA or something.

3

Is that an official Arduino board or a clone ?

4

Looks like it was rubbing against something. If not for the fact that it's not working, I wouldn't give it a second thought.

5

That is correct for most board factories. Where ever you got the board should quickly ask for it back. Did you notify them with the same pictures?

6

I added some additional info in the opening post.

Yes I sent these pictures to the webshop and I'm waiting for they're reply.

7

These do not look like traces of previous use/soldering on that board.

I expect that board to work, but that one of the cleaning steps in their PCB manufacturing process isn't optimal. Honestly, I'd shrug, power the thing up and move on.

8

Yeah, if it worked I'd do the same.
Thing is, it doesn't work, the TX doesn't go high .

If I got a board like this and it worked I wouldn't even have posted this question.

I'm still waiting for a reply from the web shop at the moment.

9

Ok get your concern in that case.
Is TX pulled up on that board or is it a naked open drain? I assume you've tried pulling it up externally in case of the latter.

10

Thanks for your suggestion rsmls but I tried just about everything to diagnose and solve this UART issue. It's a write off and I'm not putting any more effort into it.

11

Sometimes, it's no use. Too bad about that board, sorry to hear it.

12

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