PSU Earth Ground/Neg.

[BILLPOD]

Good Morning All,  I've had a Dr. Meter DC bench power supply for a few years now, (model # PS-305DM) and just discovered that the negative banana jack is internally connected to the earth ground banana jack, (which is connected to my mains earth ground).  I can't believe I haven't blown something up
while probing devices with my scope, (devices I'm powering with the PSU.
     I'm going to tear into the PSU to disconnect my neg from earth GND, but I'm wondering if any of you have resolved this issue and can point me to where this connection is, inside this PSU.  Thank you in advance.

[J-R]

I have the same power supply but mine has an external flat bar connection between the negative and ground posts.  Without it I measure about 20MOhms between the two terminals.  So hopefully it could be a simple internal modification.  Have you taken a look inside yet?

[bdunham7]

I had a similar issue with a power supply that used tantalum capacitors as EMI filters or whatever from all the floating grounds to earth ground.  One of them shorted.  You probably just need to take it apart and you may find something like that or something physical that has connected.