GI: global or general illumination is something you'll often hear on pinball repair websites. With GI people mean all the lightbulbs that are not controlled by the processor that controls the pinball machine. Switch the game on, and these GI lights will immediately come on. (so no, because the lights come on doesn't mean that a game is functioning !).
The problem with most games is that the connectors and components used for this illumination usually get problems when games are switched on for many hours.. some games on location are only switched off a few hours at night, or sometimes aren't switched off at all for many days, weeks or sometimes even months.
Especially the connectors and header pins will discolor and burn. If it becomes too bad they need to be replaced.
Some pinball machine owners replace therefor #44 light bulbs with the #47 type. This type of light bulb
uses less amps, so puts less stress on the components. However they emit noticeably less light.
I personally don't like those dim lights. Most recent games don't have a lot of light bulbs already on the playfield, and in home use you normally don't leave your games on for many hours each day.
So only on a few locations, like in pop bumpers and in other enclosed plastics I will use this type of lightbulb.
The connectors and header pins that provide the GI lamps of power, often become too hot and burn (causing more resistance and heat). Replacing them is the only good solution.
The problem is that you need to be skilled to make these repairs. If you don't know how to solder it is better to leave this alone. And I also heard that some pinball shops start the rumor that it's safest to replace all GI pins and connectors (and all capacitors while you're busy) on every pinball machine. While in theory this may be needed, on most pinball machines this is not necessary at all and is only good for the pinball shop itself, as he will have a lot of repair to do and kits to sell.. (only if you have reset problems and replace the bridge recifiers, you should replace the associated capacitors as well). Replacing parts just in case when you are not good in soldering can introduce more problems.
So if you can't solder well, is there nothing you can do to prevent this damage from happening ?
Sure you can !
First don't leave your pinball machine on for many hours. It can handle it, but if you're not going to play for a long time, it's better to switch the game off.
What is important on WPC games is to change the power saver in the settings.
In Adjustments A1, set the Power Saver Level to 4 (default on 5) and Power Saver Time to 2 minutes.
If the game is not played for 2 minutes it will automatically dim the light bulbs a bit.
Connectors J120 and J121 are for the GI to the playfield and backbox, but can be switched.
Every pin of J120 is connected to the same pin on J121. This means that you can switch the connectors
without any problem. This little trick is the cheapest and best thing to do when you buy a new game
that has been on location before.
There are usually only a few pins used in common on both connectors. All the other pins will be free on one of them. If any of the non-common pins starts to discolor on one of the connectors, just switch the position of the connectors on J120 and J121. From now on this discolored pin will not be used anymore (and can not get damaged any further).
Note this trick is only 'safe' to use when the connectors still look like the picture above.. so when there's hardly any burn to notice at all. If connectors look like in the pictures below, they (together with the pins) really need to be replaced and fixed !
Bad repairs will not last. Cellphone picture, but you see the wires have been soldered to the header pins. 3 wires had connector strips on them - the middle one just melted completely !