I had the incident yesterday. The Banned Screen appears before to have the chance to introduce the data to login, I had a previous one in a different place, connected to a different net. So, it appears to be random and not related to the person or the point of connection.
Not exactly. Suppose we need 100R.
Paralleling two 200R: 200R + .5% = 201, in parallel 100.5R, exactly 100R + .5%, Although with less probability of the maximum error.
This is the Dynalo PCB I am using.
I ordered them from Elecrow. They are 94mmx74mm, 2 layer,1 oz. copper and 1,6mm thick. The price for 10 is 14USD plus shipping, and the quality is good enough.
Just permuting 500R and 1K the maximum Iccs does not change and the minimum is lower.
For a LED with Vf=1.8V:
Imax= 3.6mA and the minimum of 2.52mA change to 1.31mA
The current source/sink LED (859-LTL-4213) has Vf=2.1V. So, with R1/R4 of 500R, the minimun possible current is 3.15mA.
I'm using 1K to regulate the current from 1.65mA and up.
For the gain, I'll try 20K for R52/R56 and 10pF for C1/C3.
Do you think that these changes are appropriate?
I don't know if it is too complicated to do (or even convenient) but I believe that moving the heatsinks, and the transistors, to the other side of the PCB would improve the cooling.
I don't know if this is a solution but there are dielectric liquid coolants, such as silicones, used in the electric and electronic industry, as an alternative to water.