the Spinner will only make the "Vaus' go right , but cannot get it to spin left.
You get a quadrature waveform like this on the data lines when you turn the spinner clockwise. (. . . 1 2 3 4 1 2 3 4 . . .)
When you turn the spinner counter-clockwise the pattern is reversed. (. . . 4 3 2 1 4 3 2 1 . . .)
Since the Vaus moves to the right, we know that the spinner optical circuits for both data lines are working correctly, providing logic highs or lows depending on whether the encoder wheel is blocking or not blocking the gap between the LED and phototransistor.
The problem must be on the game PCB where the logic levels on the spinner data lines are translated into movement steps for the Vaus.
One potential issue is that Arkanoid was widely bootlegged, so the first thing you should do is find out if you have an original or a bootleg PCB.
- The rest of this post assumes you have a non-bootleg PCB.
The schematics for the non-bootleg PCB are somewhat difficult to find, but I found a partial version at
http://wiki.pldarchive.co.uk/images/e/ec/Arkanoid_schematics.pdf.
The schematics are incomplete. Various signals and custom chips are not present in this schematic
The closest things I could find are on page 4, top center where you see ovals with G-15, G-16, G-S, and G-T.
- These are the data lines for P1 spinner and P2 spinner (cocktail cab) according to page 2 of the manual
here.
The connections aren't shown in the schematic, but it looks like the data lines might pass through the 74LS157 to the 74LS669 chips on page 4, upper right.
- Far as I can tell, the physical location of these chips on the PCB is shown on page 5, coordinates G-8.
-- On page 5, the 74LS157 is labeled "IC 11" ("IC 7" on the PCB) and the 74LS669s are labeled "IC 23". ("IC 5" and "IC 6" on the PCB)
-- Check if there are traces connecting the data lines to these chips.
74LS669 chips can be used as quadrature decoders as mentioned
here.
- One output from the 74LS669 will tell the PCB when to move one step and another output will tell it which direction to move.
- Looks like something (bad chip, broken trace, short circuit, etc.) is preventing the directional output from changing.
Scott