Asteroids - tantrum then constant reset loop

[pooman2084]

Hello,

I picked up this nice cabaret:

http://www.ukvac.com/forum/forum_posts.asp?TID=329814&title=asteroids-cabaret-500-sold

But it's a bit poorly after it's journey to my house.

I had one game on it with the sound issue mention in the FS post, left it for a while, was just going to play it when I noticed the rocks getting larger and smaller then the bullets stopping on the screen. I went to have a game, some diagonal lines apperared then it reset within a few seconds.

After a few power cycles it now just flashes the LEDs, but in a fast non-patterned way rather than a regular flash or pulse. It seems to be constantly resetting. In test mode it does two low tones then stops.

Now nothing on screen, but yoke is glowing.

The board has 4.8v on the 5v line. 10.2v on the other.

I've since put the jumper mod on as Guddler suggested but no difference.

Any ideas? I'm not particularly handy with a soldering iron, but don't mind getting my hands dirty within my limits.

Cheers

Lloyd
pooman20842011-11-24 21:09:51

 

[pooman2084]

30 views and no suggestions?

Help out an Atari virgin please!

 

[Alpha1]

What's the pcb do in test mode?

 

[pooman2084]

Two beeps (low tones) then nothing. Nothing on the screen either in test or game mode.

Should I start at the PSU and go from there? How do I measure whether the 'big blue' is functioning properly?

Thanks Ol.

 

[Alpha1]

Have you checked the manual to see what the low tones are? I recall boops (low) rather than beeps (high) indicate chip failure, and this is the process for telling you what has failed.

The manual should explain it http://www.classicgaming.cc/classics/asteroids/tech.php

 

[Alpha1]

Just looked at the manual - If there is no other fault causing this looks like you have ram chip failure - the manual shows you which ones for the # of beeps.

 

[gridrunner]

If it was working before it was moved, then it might be worth trying the obvious things first. Try removing and re-seating wiring connectors and carefully remove and re-seat socketed ICs. Be vigilant for pin corrosion before doing this though.

Is the game presenting the same symptoms if booted from cold?

If you're noticing the game progressively failing from being switched on from cold, a cracked solder joint from the journey could be an issue? Might be worth reflowing solder joints for the wiring harness and just generally TLC.

Would be good baselining practice in any case before going into technical depth. I've lost track of the number of games that presented with weird faults after being moved somewhere.

Stu

 

[pooman2084]

Thanks both for your advice.

I did try reseating the cables, but will try the sockets later too.

The way I read the manual was that I should get 5 beeps of various pitch, so was stumped by only getting two.

Let me have a go and I'll report back.

 

[Alpha1]

The manual says the sequence stops at the last failing ram chip.

 

[guddler]

I'm not in front of the manual right now (am working) but I believe that's one or both of the two program RAMs. As gridrunner has said, since it's been moved about, reseat those two chips first - they're down near the 6502 processor. If not, it's perfectly possible that a RAM or some other chip has just gone bad. Happens randomly all the time.