Refurbishing Vacuum Fluorescent Display - Do companies exist? - Page 1
Forum section: electronics / projects

author: rfdes
author_rank: Regular Contributor
timestamp: November 23, 2022, 03:43:52 pm
content: Hi -I have an '90 vintage Fluke 6080A/AN signal generator that I enjoy using. However, the VFD finally bit the dust (due to my negligence I might add) and does not display any image. The filament cathode coating has finally burned off completely. I could look for another parts unit for a display donor but figured it likely will be toast as well or least on its last leg.Are there existing companies that can 'refurbish' a display unit? Seems unlikely and if so the cost would probably be prohibitive but I figured i would reach out anyway and explore the possibility. I am attempting to save myself a lot of work designing a new OLED display to replace the bad display.Anyone have knowledge regarding companies that refurbish these displays?thanksJim

author: coromonadalix
author_rank: Super Contributor
timestamp: November 23, 2022, 03:47:40 pm
content: I think they wont refurbish, i dont think you'll find a company ?? (never heard of) they only want to sell ...unless you design you own substitute display ....

author: rfdes
author_rank: Regular Contributor
timestamp: November 23, 2022, 04:01:54 pm
content: I agree the chances are nil, but you never know!I saw recently on a news program a fellow that still has a business mass copying floppy disks for companies. He claims his business has increased recently. I realize that copying floppy disks is a far cry from refurbishing a VFD but it wouldn't surprise me if there was not a company out there that does this.

author: LaserSteve
author_rank: Super Contributor
timestamp: November 23, 2022, 06:57:50 pm
content: The low melting glass frit they use to bond the display is likely vitrefying frit. It changes to a crystalline state once bonded. the remelt temperature would likely be higher then the sealing point. It does diffuse into the substrate slightly.It would be a nightmare to try to remove or grind offthe remaining frit on the substrate without doing damage to the ITO, feedthroughs, Phosphor, Grids, ETC.A remelt would have the consistency of glowing hot road tar.Military CRTs are still rebuilt, but unlikely to ever see a VFD remade. The materials are just too fragile when not a sandwich.I have several types of bonding frit, this is not speculation on my part.Sorry,Steve

author: james_s
author_rank: Super Contributor
timestamp: November 23, 2022, 07:24:35 pm
content: I don't see how you'd ever get the thing apart without completely destroying it, unless maybe grinding the faceplate completely away on a diamond wheel. It's likely going to be much easier to find a company that will make a custom VFD from scratch than to rebuild an existing one. Somebody got some custom LCD displays made a few years ago, a similar service might exist for VFD.

author: PaulAm
author_rank: Frequent Contributor
timestamp: November 23, 2022, 08:08:20 pm
content: From what people have successfully done for a number of instruments seems to be to reverse engineer the comm to the display and then build a replacement using their technology of choice (LED, LCD or OLED). One example is, the LED replacement display for the Fluke 8840 series DMMs. I saw another one the other day where alphanumeric LEDs were used for a VFD replacement. Turned out nice, but some of these are too labor intensive to be a practical drop-in kit.

author: rfdes
author_rank: Regular Contributor
timestamp: November 23, 2022, 08:12:20 pm
content: Quote from: PaulAm on November 23, 2022, 08:08:20 pmYes, this is what I am anticipating doing. It'll be some work, however. I've already got a list of concurrent projects the length of my arm. Avoiding another project is in my best interest.Thanks to all for their input.

author: Gyro
author_rank: Super Contributor
timestamp: November 23, 2022, 08:44:06 pm
content: Quote from: james_s on November 23, 2022, 07:24:35 pmThe front glass is held on with 'glass frit' which has a lower melting point than the rest of the glass (and the internals, including the phosphor). Obviously the pins would have to be replaced. Theoretically you could heat it enough to remove the glass, replace the filaments and getter, re-fit the front glass and then re-evacuate it using the glass pip at the back (which is also secured with frit). Finally re-firing the getter and attaching new pins.Whether it would ever be cost effective is another matter but it is theorecically feasible. Of course this would only treat filament emmision failure. Accurately re-screen printing the phosphors on the anodes, behind the spot welded grids would be quite a few levels up in terms of complexity.