The story started on Sunday suddenly decided not to work no display.
I opened the power supply A22 board and found a dead 6.2 volt zener diode. Looks like new.
There is still no display. I did a diagnosis for the provider without load
There were voltages 15 plus 15 minus 5 plus
Strange. It took me a while to realize that the problem is in the standby circuit
transistor. npn q301 which is part of the standby start-up circuit was shorted.
I didn't have exactly the same one in size to-92
I had a c945 model which is close
But the leg of the base is not in the middle.
I twisted the small leg to the middle. I isolated me with a shrink nancy
The provider went back to work with a bunch of errors.
010
026
039
013
There was no voltage the device output correctly did not receive negative voltage with error 010
The frequencies were shocking, nothing wrong, it registers 2 volts and comes out 7
Writing minus 5 volts outputs 2.4 volts.
In short, the generator was seriously ill.
It took me another day to realize that the problem was in the doubt
a 15 microfarad 20 volt tantalum resistor to die in such a way that I thought a cockroch was electrocuted in the device.
I did thinking it can't towards.
I understood that a single cable from the power supply transfers minus 15 volts in a single thin cable to the A14 board
And actually the power supply broke down, the voltage was the unstable 24 volts from the track. That fried the tantalum and 3 more resistors
12 ohm
3.9 ohm
100 kilos
In the area where the negative voltage was 15 volts to transistor Q209
2 capacitors
10 nanofarad ceramic changed to 10 nano np0
15 microfarad tantalum was replaced with a 22 microfarad polymer
3 resistors were replaced
12 um which I measured exactly 12
100 kilos too
And 3.9 ohms that I didn't have, I created through 2 samples in parallel 5 ohms in parallel with 22 ohms
which I physically measured 3.95 ohms
I did point to point threading for everything and cleaned up.
And the generator returned to full life
I did full recalibrated the 3225
And the generator is now as accurate as ever
Home
Help
Search
Login
Register
