Starwars PCB Troubleshooting help needed

dezbaz

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Donor 4 years: 2011, 2013-2014, 2016
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Hi Guys

I have vector problems on my star wars PCB. And, after 10 - 15 seconds the game starts resetting too

Has anyone got some troubleshooting links / info on the net please?

:)
 
Have no idea what ur issues are...but mine was a simple bad AVG chip. Had vector issues as well plus screen freezing on the esb part of the game. New AVG chip from arcadeshop fixed it right up...good luck!
 
Have no idea what ur issues are...but mine was a simple bad AVG chip. Had vector issues as well plus screen freezing on the esb part of the game. New AVG chip from arcadeshop fixed it right up...good luck!

Thank you

I may just need to start a repair thread to get it going, once I narrow things down a bit

:)
 
Thank you

I may just need to start a repair thread to get it going, once I narrow things down a bit

:)

Might be fun, I know how useful your amplifone parts list was the other week.... In any case I'm currently ploughing through some dead avg boards. The Atari troubleshooting guide has been useful so far, the self test fixed one board simply by correctly identifying a duff eprom (or maybe just the socket- I ended up replacing both). I found some other repair hints too but nothing outstanding so I have been searching through vectorlist archives so far and some of the old stuff on here http://gamearchive.askey.org/Video_Games/Manufacturers/Atari/starwars.html for inspiration. At the moment by looking at the AVG schematics I can't really visualise what areas of the circuitry would be causing certain problems, unlike the main board which seems a little more obvious....
 
Please correct me if I am wrong but bad AVG's don't seem to make the game crash right ?

Bad video RAMs do.....I've been there. The first bad video RAM I had only caused graphic errors and was correctly diagnosed by the HW tests (double checked by swapping two locations).
The second that went bad produced graphics issues and would make the game crash after a little while. It was repeatable too (always crashed at the same moment) and was also correctly diagnosed by the HW tests.

Dez....get going, how long does it take to go through those tests in Australia ?? :):):)
 
Mine did...was having vector issues with the shield on the star wars...and it would freeze about 5 seconds into esb...it would freeze...go black...freeze...black...etc. the new AVG chip fixed the problem. So now u got me wondering if I am gonna have more problems soon and the AVG chip is just a band aid for a deeper problem.... hope not...
 
LOL

Gotta do this
1. Finish Bloody Kitchen
2. Get my empty property rented out (After renos)
3. Fix star wars
(

Pfffff

1. Takes couple of days
2. Can take MONTHS !
3. Takes 2 minutes

;) ;) Just kidding, I know how these things go, believe me....been redoing our living room....never seems to end !
 
Pfffff

1. Takes couple of days
2. Can take MONTHS !
3. Takes 2 minutes

;) ;) Just kidding, I know how these things go, believe me....been redoing our living room....never seems to end !

My shed is set up to cut wood panels, so needs a clean up then I will be away pretty soon . . .

:)
 
Well, I had a 'gate array' custom that was dead and it didn't stop the board running but it did make the display drop out every second or so causing the spot killer to cut in. Viewing it on a scope the game was almost hanging and playing in slow motion but I dont think it was watchdogging initially but it did hang eventually.

I also had a bad eprom causing vectors to be drawn off the top of the screen but it still ran fine.

So it seems that the game might run with a mangled AVG and then again it might not. My latest main board repair went well and then the AVG failed minutes later (grrrr!), firstly drawing stuff all over the place (on a scope) then I got a dot. Strangely cranking the scope up to it's maximum sensitivity and setting the probes to 1:1 I can still see everything being displayed properly, albeit very small. I am thinking DACs but I don't see why the X&Y would fail simultaneously. I'll be doing more investigations in the next few days.
 
Hoping to get onto this soon, some big personal hurdles almost overcome :D

Hey, whilst I know it's largely irrelevant to your post I can report that i have now fixed that particular AVG PCB. Basically it turned out to be a duff 74LS161 at 1D on the vector timer. The troubleshooting diagnostics showed a waveform that was wrong: test 4 (figure 2 page 6 of troubleshooting guide) was inverted. I spent ages blundering around on this one with a scope and logic tester but eventually I traced it to this part of the circuit by accidentally and briefly shorting the VCTR test point to 'PR111' which caused the waveform to switch to the right phase and was reproducible, funny how things turn out.

Suffice to say the vector instructions tests that can be selected by the option switches are very useful for generating repeatable waveforms when testing against a known good board. I compared the vector test point in demo mode with a good board and the only discernible difference was the intensity of the signal between high and low and I don't think I would have spotted it.
 
Hey, whilst I know it's largely irrelevant to your post I can report that i have now fixed that particular AVG PCB. Basically it turned out to be a duff 74LS161 at 1D on the vector timer. The troubleshooting diagnostics showed a waveform that was wrong: test 4 (figure 2 page 6 of troubleshooting guide) was inverted. I spent ages blundering around on this one with a scope and logic tester but eventually I traced it to this part of the circuit by accidentally and briefly shorting the VCTR test point to 'PR111' which caused the waveform to switch to the right phase and was reproducible, funny how things turn out.

Suffice to say the vector instructions tests that can be selected by the option switches are very useful for generating repeatable waveforms when testing against a known good board. I compared the vector test point in demo mode with a good board and the only discernible difference was the intensity of the signal between high and low and I don't think I would have spotted it.

Cool, thank you

Nice
 
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