Heat development of 64x32 RGB LED Matrix

Hi there,

I am using 64x32 RGB LED Matrices in a project where heat development (even some degrees) is a problem. When the LED matrix is connected to the power supply (no LED are lit), there is a heating up of the matrix around 4-7 degree, especially at the location of the micro-controllers. This is expected for me.
In my project, the matrix has to work only for short periods of time; e.g. 1h break, 2s lighting up, 5 min break, 2 s lightning up, ... So I though, I just interrupt the power supply to the matrix (no power, no warming) during the "breaks".

I now realized, that if the matrix is connected to my Arduino mega and NOT connected to the power supply, the connection of the IDC cable to the matrix warms up very fast (see [image](https://photos.app.goo.gl/axKjvMW1nv2dhCxb8); FLIR of the LED matrix. Left: power supply not connected, right: power supply connected)

1. Why is this connection only warming up when the power supply is not connected? (I don't have a lot of electronic background)

It only warms up after the begin.matrix() function is called. I measured the pins of the Arduino. The 4 analog pins show 2.5 V, the CLK, LAT, OE around 0.4 V (?). I looked to the code of the RGB-matrix-Panel library but could not really make sense of it.

2. Is there a simply (software) solution?

E.g. a simply way to write a matrix.stop() function (so i could use them before a "break"). Or can I just manually set the (analog) pins to 0V and up again before I need the matrix?

I hope I could explain the problem and thanks for your help. Best,
lorach

Start by reproducing the reported heating with the RGB-matrix-Panel library and Arduino Mega, comparing the matrix connected and disconnected from its power supply. Read the library behavior triggered by begin.matrix() and inspect the reported analog, CLK, LAT, and OE pin states; done means the cause and any safe software control approach are documented.

Written by the indexing model from the issue text.