Dead Pinball?

Dead Pinball?

Sometimes you think disaster has struck, you turn your pinball machine on, only to find that it is either dead or seriously malfunctioning.

If the machine is totally dead, yet it worked perfectly last time you turned it on, it can be quite confusing.

The following are the most common reasons for the machine not to work.

(1) Plug fuse blown, must be replaced with a 13Amp plug fuse.

(2) Internal mains fuse blown, must be replaced with a 8Amp slow blow 1 1/4″ type fuse, sometimes games intended for use in the US use a label near the internal fuse stating “4A Slow Blow”, this is because different mains voltages apply in other countries. Ignore this and replace with an 8Amp.

(3) The ‘Euro’ power lead (games late 1992 onwards – Fish Tales & Dr, Who) has become loose at the back of the machine. Remove cover and check that the lead is correctly installed,

(4) Replace ‘Euro’ lead.

If you still have no success, ‘phone us.

Problems with game features.

‘A’ Solenoids.

(A1) On games 1993 onwards a high voltage interlock was introduced which disables the +50VDC and the +20VDC, MAKE SURE COIN DOOR IS CLOSED!

(A2) Check fuses on top right-hand side of the WPC Power Driver PCB (the biggest board in the backbox) with multi-meter, not just visually, sometimes fuses can look alright but are in fact blown.

(A3) Put the machine into test four (solenoid test) and (with the interlock switch closed) press ‘Enter’ twice.

The number next to T.4 should be increasing (01,02,03 etc), if some of the solenoids are working and some not, write down which are working and ‘phone us, or look at the solenoid chart on the inside page of the manual, all solenoids will be listed. If all of the ‘high power’ or the ‘low power’ solenoids cease working together, this indicates that a fuse has blown (check the five fuses in the top-middle of the power driver), – this is usually the cause of solenoids failing.

If only one or two solenoids are not working, check that wires havn’t worked loose or fallen off the coil (under the playfield)

‘B’ Switches

Problems can occur which can make the game act irratically,

namely, switches failing to operate.

Firstly write down which switches are not working, if the swiches fall into a ‘column’ or ‘row’, for example, say the following swiches are not working;

SW13, 23, 29, 33 and 43, this indicates that the third row is at fault. Because SW13, 23, 33 and 43 are four switches on the same row. This is unlikely to be a board fault, more likely a wire has fallen off a target.

On a typical switch matrix of 64 switches, only 16 wires out of the CPU board are used, Therefore each column and row use one ‘common’ wire. When a ‘common’ column wire is connected to a row wire, a closed circuit, at that junction is detected and interpreted as a closed switch.

So, if the common wire joins four switches and then breaks off, no circuit to the other four swiches in that row (or coloum) is possible and after 30 games (or 90 balls) the machine indicates there is a problem by displaying a dot after the credits.



X = The number of credits.

Locate the picture of the switch matrix in the manual (usually the back page) and note the faulty row (or column), then look at every switch on that row (or column) checking the wires are intact. Gently pull the wires to make sure that both wires to each lug is connected (the swtich at the end of the row or coloum will only have one wire connected). When you find the loose wire, re-solder it to the switch (with the game turned off).

Now, the other faulty switch (SW29) could be a misadjusted, have one of the contacts broken, or have the diode broken. Put the machine into switch test (T.1) and ‘short’ out the switch by touching the GREEN and WHITE wires together with a piece of wire, if the machine makes a sound, it has ‘read’ the switch and therefore the switch must be replaced.

Leave a Reply