Easytouch 4 RS-485 Repair

[ajw22]

That's what I was thinking, but on the other hand that little protector component seems like very cheap insurance, even if it would only be effective under certain circumstances.

That little component can also be another point of failure to cause RS-485 comm problems. TANSTAASFL

 

[Dirk]

That little component can also be another point of failure to cause RS-485 comm problems. TANSTAASFL

Good point.

PS. Well, TANSTAASFL to you too, man.

PPS. Scratch that. (I had to look that one up. Though to be honest, I have to look most of 'em up!)

 

[sinister2c]

I just did that troubleshooting with the board pins on the back side of the RS-485 check. All 5V so I decided to order both recommended chips from Mouser (Digi-Key has them too), I am order 2 and 4 of each in case it happens again or doesn't work on first try since they are cheap.

The Maxim brand is more expensive, MAX1483ESA+T, at $4.50/ea
The Renesas Electronics , ISL81483IBZ, is about $2.30/each
Economy (probaby 1st class evelope) shipping was $3.49.
I'll probably make a detailed YouTube video to document the troubleshoot, desoldering, and repair.

 

[sinister2c]

I just did that troubleshooting with the board pins on the back side of the RS-485 check. All 5V so I decided to order both recommended chips from Mouser (Digi-Key has them too), I am order 2 and 4 of each in case it happens again or doesn't work on first try since they are cheap.

The Maxim brand is more expensive, MAX1483ESA+T, at $4.50/ea
The Renesas Electronics , ISL81483IBZ, is about $2.30/each
Economy (probaby 1st class evelope) shipping was $3.49.
I'll probably make a detailed YouTube video to document the troubleshoot, desoldering, and repair.

Everything is fixed now for the RS-485 comms...Screenlogic is back in business. But right after my fix, I noticed that the outputs on the second half of my board had failed on (relay 4 was always hot and no signal to my MasterTemp400 heater). That will be a troubleshoot for another day, my first 8 I/O seems to work fine but the second 8 are bad. I assume its a transistor probably as there are two chips that contain all the transistors...once I fix, I'll have a video on that repair.

In the meantime, this is my RS-485 chip troubleshooting and fix video.