Atari Star Wars popping sound issue & LEDs

[Ghostlyguy]

Working on this Atari Star Wars, the speakers are producing a rhythmic popping sound. Buh-duh Buh-duh Buh-duh... its a very annoying sound thats pitch causes hearing damage so I turned the volume pot down to work on other parts of the machine as I am still troubleshooting the monitor, flight-yoke, etc.
The popping plays during all modes (test, game, attract)

I think at least, most, if not all of the sounds/music are working fine during gameplay. Plays attract sound etc. (I need to check some more)
Sometimes the popping sound will stop briefly depending on where the game play is, which I guess means its is a boardset issue? I reseated all the chips and cleaned the connectors/sockets/legs with deoxit... as ideas what should be replaced?

 

[Ghostlyguy]

No progress on the sound but made a lot of progress on the amplifone monitor, was completely dead, now working with great, sharp colors. Fixed the dumb focus issue. It had a broken focus wire under the boot on the flyback. Good enough for now, will come back to it later.

Looking for the definitions for all the LEDs in a Star Wars machine; is there a guide for understanding what the blinks/on/off mean?

HV board
Deflection board
Game boards!

 

[andrewb]

The deflection board LED is the spot killer. It works the same as all other vector monitors, and turns on when there is no deflection currents in the yoke (which can be due to having bad/no signals from the game board, or a separate issue in the deflection system itself.)

The HV board has the HV overvoltage trip LED, which if it's on means the HV overvoltage circuit tripped, because the HV exceeded whatever the trip level was set to (which you set using the procedure in the Amp manual. Or just leave the trip level set to max, to effectively disable it.) But the LED should basically always be off, unless something is really wrong.

For the LEDs on the game board, see here:

https://arcarc.xmission.com/PDF_Arcade_Atari_Kee/Star_Wars/Star_Wars_SP-225_1st_Printing_Troubleshooting_Guide.pdf

 

[lilypad19]

You can test the sounds pretty easily. On the sound board TP7 - Test.. clip it to ground and you will get all of the sounds to play. If there are any bad ones.. take note and then swap Pokeys around and see if the bad sounds move. This assumes it is from sound board and not elsewhere of course.. I generally do this while it is on a (quiet) diagnostic screen.

 

[DavidShoe]

Are your speech sounds working? I have a had this problem with SW Sound boards before, the popping is the board turning the speech chip power on and off. Use a scope at pin 4 of the TMS52220 and see if it is changing in time with the popping.