Micro Dot pHAT issue



Is this the micro dot phat as I have a similar problem. On the second matrix all the LEDs on the first column fail to light and the first row on the first matrix is brighter than all the others

I originally thought I’d damaged the display when soldering so bought another pair of matrices but the problem persists. Any ideas?



Left red pixel on dot breakout not working

Your pHAT does not appear soldered at all, how is it kept in place? Granted that is unlikely the problem, it is surprising it even works at all.

Anyhow, the problem the screenshot you posted typically results from a bridge of the IC itself, which would be the one marked ‘0x63’ in this instance.

We do test for issues like these as part of the QA, but it is quite possible that you created the bridge when soldering the LTP305 just below it. Can you post a pic of the underside?

… either way, to be honest, it’s quite a precision job i.e difficult to un-bridge an IC so you may have to drop an email to support@pimoroni.com and see what potential help we could offer.

(Note: the product referred to in the OP was a different one… so moved to this topic to avoid confusion!)



Thanks for the reply and for moving the topic.

The phat isn’t currently soldered as I wanted to test it first. I’ve found in the past that you can usually get through hole plated PCBs to work without soldering parts in. I have a Atmel Processor that I have programmed using this method of inserting pins without soldering.

I’ve examined the chip using a watchmakers loupe and attached the above photo. I can’t see any obvious solder bridges.