Trying to repair 2230 tektronix oscilloscope. When I checked it I found two rectifier diode shorted. Cr907 shorted, u930 blown, q908 shorted, cr908 shorted and of course q9070.
Replaced all the component and power on the equipment in this case it took away fuse, two rectifier diode and q9070.
I Google regarding the issue, most of the site suggest to change the old capacitor in the high voltage and low voltage side of the power supply.
So I changed all the electrolytic capacitor and c907.
Those capacitor are not tectronix original.
Changed the blown parts again.
Power on the oscilloscope it again took away rectifier diode q9070 and cr 907.
People are also suggesting to remove molex connector on q9070 and directly conennect wire with the transistor pin.
How important to do this. Will connecting wire directly to the pin of q9070 help a lot in my case.?
I wanted to change all the capacitor in the line filter module but could not because it is hard to find in my area.
Right now the scope is in following cndition
1changed all the capacitor except C900, C902, c903, C904, C922, C919, c908 andC919.
2 I have not connected the molex connector. Take
3 in this case I can safely power on the scope.
4 I measured the voltage in the preregulator it seems OK.
5 I measured the voltage at base of q908 and I get pulsating voltage which drag me to conclude that u930 is oscillating.
6 measured the resistance at ground (tp950) and tp950 which is around 8ohms.
7i am very much reluctant to connect molex connector to q9070 thinking it will take again those transistor and diode.
I would appreciate if some one guide me on this issue.
Replaced all the component and power on the equipment in this case it took away fuse, two rectifier diode and q9070.
I Google regarding the issue, most of the site suggest to change the old capacitor in the high voltage and low voltage side of the power supply.
So I changed all the electrolytic capacitor and c907.
Those capacitor are not tectronix original.
Changed the blown parts again.
Power on the oscilloscope it again took away rectifier diode q9070 and cr 907.
People are also suggesting to remove molex connector on q9070 and directly conennect wire with the transistor pin.
How important to do this. Will connecting wire directly to the pin of q9070 help a lot in my case.?
I wanted to change all the capacitor in the line filter module but could not because it is hard to find in my area.
Right now the scope is in following cndition
1changed all the capacitor except C900, C902, c903, C904, C922, C919, c908 andC919.
2 I have not connected the molex connector. Take
3 in this case I can safely power on the scope.
4 I measured the voltage in the preregulator it seems OK.
5 I measured the voltage at base of q908 and I get pulsating voltage which drag me to conclude that u930 is oscillating.
6 measured the resistance at ground (tp950) and tp950 which is around 8ohms.
7i am very much reluctant to connect molex connector to q9070 thinking it will take again those transistor and diode.
I would appreciate if some one guide me on this issue.