VFD Display Burn Mark ?

Hi,

Have a display 128 x18 thats going faulty, loosing the intensity on some of its horizontal lines.

When checking it out, found that it had a type of ' burn' mark, bottom right, but no idea if thats a normal manufacturing mark or something more recent suggesting the display is failing ?

Gather they naturally loose their intensity over time, this ones about 12 - 15 years old and been in continous on / use.

The display has a barium getter, barium is deposited on the glass during manufacture, its there to absorb an gases left during manufacture amd outgassing of the metal parts.
Dont worry about it.

Wp100 said:

Hi,

Have a display 128 x18 thats going faulty, loosing the intensity on some of its horizontal lines.

When checking it out, found that it had a type of ' burn' mark, bottom right, but no idea if thats a normal manufacturing mark or something more recent suggesting the display is failing ?

Gather they naturally loose their intensity over time, this ones about 12 - 15 years old and been in continous on / use.

View attachment 124394

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I'd say that was a getter mark from when it was manufactured.

At 12-15 years old the display has already lasted much longer than most, VFD's are particularly short lived and unreliable - they look nice when new, but are pretty poor long (or even medium) term.

Essentially it's a valve, so emission drops as it ages, then it uses phosphors to create the visible light, these lose efficiency - rapidly while running in, then more gradually over time (it's the same 'wear out' mechanism or CRT's).

Thanks for that info, not a device I have worked on before, its part of a decent hifi system.

Seems I need to replace the VFD as a matter of course just due to age and the 12+ years of continuous use, though there could always be some further problem with the driver etc.

Because its a more unusual 18 dots wide, seems the usual uk suppliers do not stock this particular model, though Noritake Itron US do list it as a current model at $56, so have mailed their uk office to see if they can help ?

**broken link removed**

Wp100 said:

Thanks for that info, not a device I have worked on before, its part of a decent hifi system.

Seems I need to replace the VFD as a matter of course just due to age and the 12+ years of continuous use, though there could always be some further problem with the driver etc.

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'Sometimes' the heater voltage is fed via electrolytic capacitors, and these do fail - however, even if they are faulty replacing them genarally only provided a little improvement, if any, and only very rarely a cure.

Because its a more unusual 18 dots wide, seems the usual uk suppliers do not stock this particular model, though Noritake Itron US do list it as a current model at $56, so have mailed their uk office to see if they can help ?

**broken link removed**

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At least it's only dots, most are special custom symbols and shapes - what make and model is the unit?, perhaps you could get it as a spare part?.

I have one somewhere I pulled it from a scrap plotter, but it too was failry worn out.
The phosphor coating on the display wears out after 10 years or so use.

Nigel Goodwin said:

'what make and model is the unit?, perhaps you could get it as a spare part?.

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Its an original Arcam Solo all in one unit (tuner/cd/amp), now well obselete, they will not deal direct with their users, you have to take / send your unit off to a local dealer who will then send it to Arcam for a repair quote, if they still have those parts in stock. Costs £40 just to send it to them, so doubt any repair will be cheap.

Could almost do without the display for most things, but trying to change channel on the fm/dab tuner would be difficult, though suppose I could just stick a more modern fm/Dab+ tuner on top.
If it was a mediocre sound would not hesitate to get something new, but it is good and most audio folk we know suggest would need to spend well over £1k to get anything as good sounding, it did cost £999 all those years ago.

The vfd I got is a 2 line affair , yours looks like a 4 line.
Mine is a standard item with a 4/8 bit interface, said interface is very common, lcd versions are common place.
Point I'm getting at is that if you surf ebay you might be able to find one of these and then you could remove the glass vfd panel from it and fit to to your system.
You'd be taking your chances but I cant thinkof a better way.

Apparently you can rejuvenate these displays, sorta like a crt rejuvenate, dont know if it lasts, if you do this you take the risk yourself I've never tried it, you might end up blowing it.

dr pepper said:

The vfd I got is a 2 line affair , yours looks like a 4 line.
Mine is a standard item with a 4/8 bit interface, said interface is very common, lcd versions are common place.
Point I'm getting at is that if you surf ebay you might be able to find one of these and then you could remove the glass vfd panel from it and fit to to your system.
You'd be taking your chances but I cant thinkof a better way.

Apparently you can rejuvenate these displays, sorta like a crt rejuvenate, dont know if it lasts, if you do this you take the risk yourself I've never tried it, you might end up blowing it.

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Will see if Noritake can supply one / reply to my mail before trying anything like that... ideally do not want to risk damaging the whole unit further.

dr pepper said:

The vfd I got is a 2 line affair , yours looks like a 4 line.
Mine is a standard item with a 4/8 bit interface, said interface is very common, lcd versions are common place.

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His is a dot matrix display, so not two or four line, and as far as I'm aware VFD's have never used 4 or 8 bit interfaces?, they are high voltage multiplexed bare displays - at least all the many I've seen have been.

EDIT: Just been and checked the datasheet he linked to, it's got a serial interface inside the glass, looks like a type of SPI connection - no wonder it's pricey. I'ne never seen one like that, but i suppose with the huge price of Arcam they can afford to splurge out on parts

Point I'm getting at is that if you surf ebay you might be able to find one of these and then you could remove the glass vfd panel from it and fit to to your system.
You'd be taking your chances but I cant thinkof a better way.

Apparently you can rejuvenate these displays, sorta like a crt rejuvenate, dont know if it lasts, if you do this you take the risk yourself I've never tried it, you might end up blowing it.

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Rejuvenation only improves the cathode emission (if it doesn't destroy it totally - as it BLASTS contamination off it), and as I pointed out (and you did as well) another issue is the phosphors wearing out.

Nigel Goodwin said:

His is a dot matrix display, so not two or four line, and as far as I'm aware VFD's have never used 4 or 8 bit interfaces?, they are high voltage multiplexed bare displays - at least all the many I've seen have been.

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Once again, your world of "everything" seems to be somewhat lacking.

Noritake has marketed LCD-pin-compatible VFD displays for some time. A few years ago, Noritake was on a hobbyist/DIYer push, giving away many of their LCD-compatible displays and providing Aurdino drivers and sample code to support and promote their use.

Your right Nige, in my old age I couldnt see the o/p's pic, it is a matrix like you said not a 'line', the o/p even said that.
Ah well, sorry o/p looks like your not getting very far with this one.

dr pepper said:

Your right Nige, in my old age I couldnt see the o/p's pic, it is a matrix like you said not a 'line', the o/p even said that.
Ah well, sorry o/p looks like your not getting very far with this one.

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I did a bit of googling about Arcam, and as the OP said, they seem a really crappy company, not at all helpful - unfortunately all too common these days.

Over a great many years I've been involved at various times with the Acoustic Manufacturing Co. who made Quad equipment. Historically they were absolutely brilliant at service, and couldn't be more helpful - me and a friend rang asking about a service manual for a Quad valve preamp, and they sent my friend one, and asked for him to pay for it once he'd received it.

An old customer had a Quad 33/303 and electrostatic speakers, and over the years had been in contact for spares and advice many times, and had got all the letters he'd had back in reply, many from the managing director. Last time I saw the guy (presumably he's died now?) he wanted me to fit some new parts in his speakers, he'd been in contact, and they had sent him the parts - but he wasn't confident fitting them.

Numerous times over the years we contacted Quad for spares, and they were always great - so we were happy to accept Quad gear for repair.

Then one day we got it touch, they had been taken over by a much larger company, and basically they were like Arcam, wouldn't supply spares or advice (even to the trade) and the only recourse was to return to them via their dealer network for an exorbitant fee.

Thinking on?, perhaps Arcam were taken over by the same people who took Quad over?.

Just checked - Arcam is Harman/Samsung and Quad is International Audio Group.

A boss of mine way back used to restore quad electrostatic speakers, didnt interest me and still not my thing.
Your right though if a company cares about its customers its a good company.
I remember asking Dta who make competition engine management sytems about a Ecu I had in a classic mini, the o/p driver had gone short for the injectors, they just sent me a pair of o/p devices and a schematic as well as a guide how to do it from thoer engineer, and all was f.o.c., thats a proper company.