CompactLogix 1769-L35E Processor unit.

CompactLogix 1769-L35E Processor unit.
I HAVE A Compact logix processor that went dead on me for no particular reason on one of our equipment. I took all the I/O out and just used the power supply with the processor. When I turn on the power supply all the leds flash red once on the cpu and the power supply dies. Could the processor draw so much curren that it would kill the powersupply?I tested power supply and seem to be working properly. Could it be the processor itself that is bad?

My best guess is that there is damage to the power circuits inside the CPU, which is drawing enough current to make the power supply go into a protective shutdown.

My standard procedure with damaged controllers is to invert them over a clean piece of copy paper and bang them on the bench a few times. More than half the time I find metal debris from careless installation.

Ken Roach said:

My standard procedure is to bang them on the bench a few times.

Click to expand...

Ken is that a RA recommended procedure ;-) What is the speed and impact force needed?

SPM would be associated with the speed of the vibration and that old annoying ring in the in my ears.
I sometimes miss that pounding of stamping presses.

Ken Roach said:

My best guess is that there is damage to the power circuits inside the CPU, which is drawing enough current to make the power supply go into a protective shutdown.

My standard procedure with damaged controllers is to invert them over a clean piece of copy paper and bang them on the bench a few times. More than half the time I find metal debris from careless installation.

Click to expand...

I can actually say that I had a successful repair of a PV300 using this method.

When I got to site, the PV300 was dead, but I found that a new E/Stop had been installed above it that very day. The electrician did say that he covered up the PV300 with a rag before drilling...

I removed the PV300 from the panel, tapped it onto a sheet of paper to collect the swarf, and hey presto, the PV300 came to life.

Sometimes you get lucky