Hi Folks,
I picked up the transistor today, I couldnt get the BC637, so I got a BC639 instead, looks like the same spec's except the max voltage is a bit higher at 80V
I soldered it in, but alas, no power at the VFD. I discovered that my multimeter has a transistor tester built in, so I tested the old one I pulled out, and I got a reasonable reading out of it. So that shot down my theory about the transistor.
I'm not sure what to check next ?
I poked around with the multimeter while it was running, and found 14V coming into the board, after switching it off, I tested for continuity between the 14V connector and the transformer, and it showed a connection, I've tested the diodes, resistors and cap's that I could see around the transformer, but alas, still nothing appears at the pins feeding the VFD.
Vedo35 - Thanks for the info, at this stage, I'm presuming the LCD display still works, there are no cracks or air gaps. I dont have any way of producing voltages to test the display like you suggested. But because there is no power going into the VFD, I presume the problem is elseware, and I'm just trying to find where.