On Mon, 28 Jun 2004 07:41:16 GMT, CJT wrote:

Here's what Sony says about one of their (fairly recent) TVs:

WARNING!

AN ISOLATION TRANSFORMER SHOULD BE USED DURING ANY
SERVICE TO AVOID POSSIBLE SHOCK HAZARD, BECAUSE OF
LIVE CHASSIS.
THE CHASSIS OF THIS RECEIVER IS DIRECTLY CONNECTED TO
THE AC POWER LINE

If you are working on the NON-ISOLATED side of the circuit, then of
course you would use an isolation transformer. If not working on the
NON-ISOLATED section of the pcb, it really doesn't matter. Take a look
at the Sony circuits. If you look around the PSU section you will
notice that they use a *fully isolated transformer*. Even the feedback
uses an opto. They put that message there for idiots who dont
understand the concept of isolation. The live chassis (you could
barely call it a chassis these days) basically means that mains power
goes to the PCB where the switchmode PSU is.

Now the fact that the secondary is isolated, is the exact reason that
you get a PD of 20Volts.

Now if the antenna, or RCA sockets were live, dont you think there may
have been a few *small* incendents to date which may have caused a few
deaths?




(The caps were in the original, which was repeated
in four different languages.)

So I think your assertion is overly broad, at least.

In context to the OP's problem, i don't think so.