K
kel-fbs
Getting erratic voltage reading near and around IC901 (over voltage
detection IC). Voltage goes from 0v - 4v back and forth at the base of
Q902 and generally around that area. On the schematic the voltage at
that point should be 0.4v. I have checked all capacitors and can't seem
to find any bad ones, infact I've checked for bad caps or transistors
on most parts of the set but can't seem to find what is causing the
problem. I thoght that I should mention the erratic voltage though as
that is about the most promising thing that I have found. At first I
though it may be an over voltage problem on the horizontal output
circuit which was tripping out the over voltage protection cicuit but
now I'm beggining to wonder if the problem may actually be the over
voltage cicuit or the chopper circuit which are both connected and the
same cicuit really.
I was also wondering if it may be something breaking down under load
due to the fact that the set will not trip out when the HOT is removed.
So it seems that the problem only happens when the set is under load.
Would really appriciate some help with this as I've been trying to get
this set working for a long time now and it's starting to do my head in.
detection IC). Voltage goes from 0v - 4v back and forth at the base of
Q902 and generally around that area. On the schematic the voltage at
that point should be 0.4v. I have checked all capacitors and can't seem
to find any bad ones, infact I've checked for bad caps or transistors
on most parts of the set but can't seem to find what is causing the
problem. I thoght that I should mention the erratic voltage though as
that is about the most promising thing that I have found. At first I
though it may be an over voltage problem on the horizontal output
circuit which was tripping out the over voltage protection cicuit but
now I'm beggining to wonder if the problem may actually be the over
voltage cicuit or the chopper circuit which are both connected and the
same cicuit really.
I was also wondering if it may be something breaking down under load
due to the fact that the set will not trip out when the HOT is removed.
So it seems that the problem only happens when the set is under load.
Would really appriciate some help with this as I've been trying to get
this set working for a long time now and it's starting to do my head in.