Very Dull Gtb Sys 1 Displays - Can They Be Fixed

[Pintoxicated]

Guys,

I have some Sys 1 displays that are very very dull.  I have tried the trick in the Pinrepair guides but it made no difference.  Are there any components that can be replaced to bring the displays back to life or are they had it?

[studley67]

what voltage are the actuall displays(glass) getting?

[studley67]

you can still but NOS plasma glass replacements,but are expensive.pbr i think.

[studley67]

from memory there are only two chips on the boards.so if they work the chips are not the problem.BUT the wiring and the pins on the wires may have some effect on the voltage getting to the glass.

[ddstoys]

With the display unplugged use a 9v battery and aligator clips put them on the two outside pins on the display glass and a wire should glow let it glow for about 5-10 second and see how it goes

[Pintoxicated]

With the display unplugged use a 9v battery and aligator clips put them on the two outside pins on the display glass and a wire should glow let it glow for about 5-10 second and see how it goes

I have tried this and it didn't make any difference whereas it usually brightens them right up.

There isn't wrong with the machine.  I bought the displays on the off chance I might be able to get them working again.  Some are missing segments which I am hoping new chips may fix but there are a few displays that are very very dull.  You win some you lose some   

[The pinballist formally known as Dean Morgan]

With the display unplugged use a 9v battery and aligator clips put them on the two outside pins on the display glass and a wire should glow let it glow for about 5-10 second and see how it goes

I have tried this and it didn't make any difference whereas it usually brightens them right up.

There isn't wrong with the machine.  I bought the displays on the off chance I might be able to get them working again.  Some are missing segments which I am hoping new chips may fix but there are a few displays that are very very dull.  You win some you lose some   

Did the filiment lines across glass glow white when u did this?  Are the filiments straight or wonky? If wonky the glass is stuffed

[Retropin]

Bloody hell.. I just replied to this at length.. hit "post" and its not here!

Ok.. here goes.. revised edition.

The plasma tubes work the same way as a neon tube.. voltage determines just how much can be run.. current its brightness. If your voltage is OK but a higher resistance is present then the current drops I=V/R.
Over a long period of time the Edison effect takes place... electrons are normally released with each AC wave back and forth.. on release the electron is gathered on the opposing charge side.. sometimes this doesn't happen and the electron gets deposited onto the inside of the glass.. it will take on a blackened look and the plasma glow start to appear slightly greenish.
If the burn in doesn't work ( this revapourises the mercury inside that has accumulated on the cathodes sending it back into the argon gas and creating UV- blue light).. then clean the contacts.. if this doesn't work then Edison has proved himself again and the tube is failing... but.... if all tubes are appearing the same then I doubt Edison is very present.. it only really happens due to manufacturing faults.. ie dirty glass, a vacuum under 10-4 or impurities in gas or mercury.

[Pintoxicated]

The filaments did glow as they normally do when burning the crap off the filaments.

Thanks Gav, I will have another play with them tomorrow and see how it goes.

[studley67]

thats why i asked him to measure the voltage.duh

[Pintoxicated]

Thanks mate, I will give the edge connectors a once over and try the displays in a different machine as well.

[studley67]

i have spare boards with broken glass if you need the chips.hard to find

[The pinballist formally known as Dean Morgan]

i have spare boards with broken glass if you need the chips.hard to find

Damien, i ordered those chips we spoke about, paid for them and never received them. Contacted seller twice he promised he resent them, it's been six months, nothing.

[studley67]

i have spare boards with broken glass if you need the chips.hard to find

Damien, i ordered those chips we spoke about, paid for them and never received them. Contacted seller twice he promised he resent them, it's been six months, nothing.

i hope you are not talking about me.i have a bad memory but not that bad.lol.i have 4 boards but i used one chip to fix blairs close encounters.if yo need them,sing out dean or anyone else.

[Marty Machine]

Light output on these displays drops over time due to falling emission and reduction of phosphor efficiency. How quickly and how far this falls depends on the construction and operation of the VFD/display.

Emission may usually be restored by raising filament voltage.
33% filament voltage boost can rectify moderate fade, and 66% boost can rectify severe fade.
However, This can make the filaments somewhat VISIBLE in use, so trial & error for preferred results ;-)

Either way, if you need to drive things harder to see them, your really only delaying the day it finally dies, which might only be 6 months away...
MM