DIYbanter - View Single Post - Who Makes Sponge-Bob Squarepants TV sets for Emerson

b

ha escrito:

b wrote:
ha escrito:

low-voltage regulator, but I haven't looked at any other similar sets
to see what that is likely to be. We'll see what happens on Tuesday,
meanwhile it's time to start gathering information for income taxes.
(Boo-Hiss)

it would be useful to see what the b+ meansures as or even if it is
present.
have you removed the line transistor and connected across c-e a 60-100w
bulb ?
-B.

I haven't had a chance to dummy up the B+, I was hoping to get a look
at a schematic for a similarly sized set and see what they run for the
B+. The power supply appears to be a full-wave bridge, but it might
also be a voltage doubler. I haven't traced out the components of the
power supply, but the diodes are essentailly across the 120V line thru
a typical line filter. I am getting +150 volts across one power cap
and -150 V across a same-sized unit right next to the first cap, that
is why I want to check to see if there is a doubler. I sort of think
that would be very unusual, but I can't otherwise explain that I can
get 300V total when measuring across the two capacitors.

I'll keep posting what I find, I may rename the subject to "More on
Spongebob TV to keep it toward the top of the list.

I wouldn't waste my time waiting for a schematic if I were you.Tech
support for this disposable product is usually nonexistant. As the set
is dead, but some voltage is present in the power supply my experience
suggests that this is usually due to it being in protection mode, often
caused by a short in the horizontal stage. See what happens with the
HOT removed and post back.
-B.