Vacuum Fluorescent Displays - How They Work & Can They Be Fixed?

I received a Yamaha MT8XII from Adrian James form the channel we happy few music for servicing, and somewhere in its journey from the south to the north ends of the British mainland the Vacuum Fluorescent Display stopped working. I've had smaller displays die on me before, but usually there was something very obviously wrong with the glass exterior - a bit broken off, a crack, etc. But this wasn't the case here. So I learned a bit about how these contraptions work, and other modes of failure. The conclusion I've come to is that if the glass breaks, spoiling the vacuum, you're stuffed. If on the other hand the glass is in tact but the VFD just isn't lighting up, you might be able to recover it . ___________________________________________________________________________________ TETRAKAN - Fix & Use Tape Recorders Overviews; tear-downs; repair vlogs; techniques; tutorials; demo recordings... ...covering every cassette multitrack recorder ever made!* *(eventually)    / tetrakan   TOOLS AND EQUIPMENT I USE;- https://kit.co/Tetrakan I post exclusive content on PATREON;-   / tetrakan   DONATIONS are gratefully accepted via my BLOG, which also features written articles and FREE DOWNLOADS OF SERVICE MANUALS;- https://tetrakansupermonobloc.home.blog/ I prefer to answer questions in the youtube comments where my answers can help more than one person, but if you need to share photos etc, you can message me via facebook.   / tetrakan   CHAPTERS 0:00 Introduction 1:00 Anatomy of a VFD diagram & disclaimer 2:00 Glass case & acuum extraction port 2:40 Three internal layers of a VFD 3:28 How the VFD works 5:20 Pin layout 6:10 Establishing the health of VFD filaments 7:10 VFD counter on a Tascam 244 9:03 VFD display on a Tascam 424 Mk II 10:59 broken pins on the MT8xII's VFD display 13:04 soldering problems 15:40 Protecting a weak solder joint with 2 part glue