Maker Pro
Maker Pro

vcr/dvd combo

S

shepleygr

Jan 1, 1970
0
the unit is about a year old. It has no power, fuse is good. PR100
appears to be open and zener 1041 is reading shorted. Has anyone ru
into this problem. If so are these the only components you ran int
that were bad

Thanks ahead of tim
 
M

Mark D. Zacharias

Jan 1, 1970
0
shepleygr said:
the unit is about a year old. It has no power, fuse is good. PR1005
appears to be open and zener 1041 is reading shorted. Has anyone run
into this problem. If so are these the only components you ran into
that were bad.

Thanks ahead of time

If the shorted zener is in the secondary area, this is often caused by bad
(high ESR) capacitors. The zener in this scenario exists in order to protect
other components downstream by shorting out if that particular power line
goes above the zener level as a result of a loss of regulation, which in
turn is most often caused by the bad caps. Replacing the caps and the zener
usually fixes the problem in these cases. If the zener goes directly between
a DC line (say the 5v or 14v line) and ground, without benefit of a limiting
resistor, that is a giveaway that this is your problem. In the situation I
have proposed, the zener does nothing under normal circumstances, thus
requires no limiting resistor.



MarkZ .
 
Top