Eight Ball

8.11.2005:


Some cleaning and this will look nice


Backglass is OK

26.11.2005:

The CPU board had some acid damage. I removed that for repairs. Now it is time to look at the playfield. It is really dirty, and the mylar is put in afterwards, right on top of old dirt.

I tried the freeze spray method with the mylar, did not work but the cold mylar was breaking into very small pieces. But heating did help, the plastic and glue softened quickly and then the mylar came off easily. I didn't do the whole sheet, because all I had for heating was a small spotlight, that only heated a small part at a time. Next time I will take a hairdryer or hot air gun with me.


Plastics and rubbers are taken out. See how the mylar has shrinked and left a dirt trace.


Rubbers were somewhat past their best before day.


These flippers have hit the ball quite many times.

27.11.2005:

The CPU board doesn't look so bad. The battery has not leaked too much yet. Some of the connector pins are totally corroded and loose, probably that's why the board did not even try to boot. CMOS RAM legs are a bit green, maybe it have to be replaced. But I am sure this board is fully repairable.



Battery leak is not acid but highly corrosive base, potassium hydroxide. It eats away circuit board foils, soldering and component legs. Usually a couple of IC's near the battery go too, when the corrosive substance slowly creeps into their casings.


Board in vinegar bath.

First the corrosive stuff is neutralized with vinegar, use a toothbrush dipped in vinegar. There might be lots of bubbling in the board, that shows the vinegar is doing its job. After a few minutes the board must be thoroughly rinsed with warm water and dried. Two lowes IC sockets must usually be replaced, and many times also some resistors and transistors near the battery.

28.11.2005:

Mylar came off easily with a hot air gun. Some glue was left on playfield, and that was removed with white spirit. No paint damage occurred, not eben to lamp inserts. But the playfield had some wear already, and it needs just a bit touching up. Maybe I could get a friend to help with that :) it doesn't look very hard and all wear is in solid coloured green area.


Playfield cleaned and new rubbers.


Close up shot reveals some wear.

The CPU board was OK, but there are still problems with the connectors. I will try cleaning, and if that doesn't help then I must replace the CPU board connectors.


Sorry, no test games yet...

10.6.2006:

Taru made some touchups to the playfield, and it looks nice! Camera flash makes the painted areas look darker than they really appear.



6.7.2007:

Summer vacation, and finally enough time to complete the Eight Ball project. I replaced the flippers, and connectors on CPU and lamp driver boards.


Old and new connectors, and a tool to insert wires into connectors.

The wires are not soldered into connectors, but instead, inserted into connectors with a special tool. A sharp edge inside connector penetrates through the wire insulation, making the electric contact. Very handy!


New connectors attached to boards.

And finally, the game is working just fine! Many light bulb sockets were bad, but good cleaning and soldering the socket tube to the base part helped.

17.11.2007:

The game moved on to the next owner.


Back