J
jss
- Jan 1, 1970
- 0
Hi,
I'm an electronics designer, not an experience service guy like most
of you, so, I need your help, please.
The problem is that the Salora service point is now closed for
holidays and my family is crying for our old and dearest TV set.
So, this is a M chassis Salora with the famous hybrid circuit in the
power supply. The set was dead, no led digit slash on the front panel.
The standby voltages were OK, so were the stby scope patterns. So, the
hybrid and the switching transistor were OK.
After short investigation the line output transistor SA2000AF was
found to be short-circuited. So, replaced most of the electrolitics
and retouched solderings for dry joints. Replaced the SA2000AF for a
BU508AF and puf! there it goes again.
Took it out again, powered the set and found that everything else is
OK although some scope patterns are slightly different but again, the
service manual that I have is for the 25M87 which is not exactly the
same. Also, the line output being off places less load on the power
supply.
So, any ideas that can help me? If necessary I can post the schematic
somewhere for downloading.
Thank in advance
jss
I'm an electronics designer, not an experience service guy like most
of you, so, I need your help, please.
The problem is that the Salora service point is now closed for
holidays and my family is crying for our old and dearest TV set.
So, this is a M chassis Salora with the famous hybrid circuit in the
power supply. The set was dead, no led digit slash on the front panel.
The standby voltages were OK, so were the stby scope patterns. So, the
hybrid and the switching transistor were OK.
After short investigation the line output transistor SA2000AF was
found to be short-circuited. So, replaced most of the electrolitics
and retouched solderings for dry joints. Replaced the SA2000AF for a
BU508AF and puf! there it goes again.
Took it out again, powered the set and found that everything else is
OK although some scope patterns are slightly different but again, the
service manual that I have is for the 25M87 which is not exactly the
same. Also, the line output being off places less load on the power
supply.
So, any ideas that can help me? If necessary I can post the schematic
somewhere for downloading.
Thank in advance
jss
