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fluke 45

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hi guys i have a fluke 45 and it has no display on the vfd at all. i have checked all the power supplies and all voltages seem to be there according to my service manual but for further investigation into what might be wrong. i need the correct display board schematic as the nec processor is different to my schematic and my schematic shows a 4.1mhz crystal on the board but my one does'nt it only has 3.6 mhz crystal on the main board all my schematics are from the attached service manual. i was wondering does anyone no if there are revision services manuals or schematics

I'm pretty sure that Fluke has made a service manual and/or change sheet for this hardware revision, but whether someone scanned and published it is another matter. I guess your best chance is to try to find as many copies as possible and hope one has the correct schematic, or otherwise troubleshoot without the correct schematic.

Did you already check the getter if the VFD is still vacuum? A vacuum fluorescent display that's not vacuum is not going to be fluorescent either ;)

ok will try thanks

hi guys i have an update
i was measuring the main oscillator crystal on the main cpu  on main board u6  HD630A3Y03  just see if the main processor u6 had good clock signal. that was preventing it from working properly a found it to be hard to measure and noisy i was measuring the pins also on the vfd and i made a measurment of the fillament voltage to ground with a multimeter and found something wierd. The display lit up which i found really weird and could not explain. so i looked all around the fillament citcuit and could find anything out of order. so i put it back together and then found if i applied a little pressure to the back of the board in certain spots the whole screen would light up brightly like norma.l i went and had lunch and then came back to it repeated the same test but got nothing but i am starting to doubt the crystal anybody else got any ideas thanks |O |O

Keep poking things with a non-conductive stick until you find the culprit?  Probably a loose solder joint.


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