Hello,
ive got a 33250A function generator where the display stopped working.
Everything else is working just fine, i can push the buttons, the waveform will output and i can change amplitude, frequency etc.
The backlight is on but nothing will show up, i opened the device and on the Display PCB (Optrex DMF-50887) are two parts blown up (D1 and TR1).
I think its part of the contrast adjustment circuit, because its connected to the little potty.
And that would make sense i guess, because the backlight is on. So maybe the contrast adjustment is just that far of, that i just cant see the text on display.
I guess TR1 is a triac. I dont have much experience with such circuits.
I found similar looking triac dimmer circuits but i dont know whats the function of IC9.
Does somone have the schematics of the Displayboard, its not in the 32250A service manual because its not from Agilent.
I can only find the datasheet (
https://www.beyondinfinite.com/lcd/Library/Optrex/DMF-50887NCJU-FW-1.pdf)
Or can someone help me how to debug this PCB.
I think its not done with just replacing the blown parts, i mean something was happening so they blew up.
But maybe that should be the first thing i have to try.
Does someone know which parts are TR1, D1 and IC9?
Hope someone can help me.
BR
Paul