Atari tempest help!

Jamesv833

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Ok I've recently purchased a water damaged cabinet, there was some slight corrosion throughout the game pcb. I've managed to clean up quite a bit of the corrosion with the help of deoxit and a nylon brush. The k6100 is currently on my bench waiting for parts(r100 blown in the lv section(waiting for lv2000). I've hooked it up to my 465b scope(I'm a noob) and managed to get a picture when I power the game straight into test mode. It's hard to really make out on my scope and it's a mirrored image(invert button only works for y) but it looks as though I have an error for a pokey(q) and some rom error(It's not really legible) I believe it's rom 8, due to me pulling one rom at a time and checking the differences on the test screen, I get an extra rom error for every chip I have pulled when I start the game(I get no image with rom 8 pulled). When I load the game normally I get some sort of garbled graphics in the center of the screen. I've resocketed every chip, reflowed several suspicious solder joints and the inter board connectors. The Voltages are; 5.09, 6.82, 14.66(?), -15.22(?), 21.79, -22.04.

Thank you
 
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I'm battling Tempest problems of my own. it just so happens mine are entirely different than yours. :)

POKEY failures are very common. as for the roms, the sockets are a weak point. if I'm not mistaken I think all the sockets may have been replaced on our board, I wanna say they're all dual wipes. regardless, roms aren't my problem. the analog video processing part has a bunch of issues instead.

the bitslicer chips can fail too, but yours aren't at fault because you have a working game. ours wouldn't play blind until I changed them all out.

a little hacky trick I use for single wipe sockets is to lift the plastic housing off and very carefully plug the chip directly onto the pins. the problem with single wipe sockets is in the pins themselves; if they get crushed (or stuffed) you can have pins that don't connect. they also break off, typically from corrosion. lifting the housing off will give you a better idea of how the pins look. given your game's history I would venture that the sockets are junk.

do you get any beep codes? I think if you have memory errors the game should beep. once again, not a problem on my end.

I found this the other night, it's about the most informative guide I've seen yet. http://www.kfu.com/~nsayer/games/tempest.html
 
Clean the legs of all ROMs with a wire wheel Dremel, or fiberglass brush. Then DeOxit the legs and sockets. If you have the gold dual-wipe sockets, they usually just need to be cleaned. But if they are the types that pinch the legs at two points, those are usually junk, and should be replaced.

You also ideally want to verify the ROMs with a programmer, as they easily can go bad, and relying on the self test isn't always the most reliable method.

Make sure the solder joints on the interconnect header pins have been reflowed.

Also, the Pokeys often go bad, so if you can swap them with ones from known working boards, that's a good thing to do. Also clean the chips and sockets on the aux board.

There's little sense digging deeper until you've verified the basics.
 
Clean the legs of all ROMs with a wire wheel Dremel, or fiberglass brush. Then DeOxit the legs and sockets. If you have the gold dual-wipe sockets, they usually just need to be cleaned. But if they are the types that pinch the legs at two points, those are usually junk, and should be replaced.

You also ideally want to verify the ROMs with a programmer, as they easily can go bad, and relying on the self test isn't always the most reliable method.

Make sure the solder joints on the interconnect header pins have been reflowed.

Also, the Pokeys often go bad, so if you can swap them with ones from known working boards, that's a good thing to do. Also clean the chips and sockets on the aux board.

There's little sense digging deeper until you've verified the basics.

No programmer, no pokeys. I have cleaned all the legs on socketed chips and went through a whole can of deoxit on this board, interconnect headers reflowed.
 
I'm battling Tempest problems of my own. it just so happens mine are entirely different than yours. :)

POKEY failures are very common. as for the roms, the sockets are a weak point. if I'm not mistaken I think all the sockets may have been replaced on our board, I wanna say they're all dual wipes. regardless, roms aren't my problem. the analog video processing part has a bunch of issues instead.

the bitslicer chips can fail too, but yours aren't at fault because you have a working game. ours wouldn't play blind until I changed them all out.

a little hacky trick I use for single wipe sockets is to lift the plastic housing off and very carefully plug the chip directly onto the pins. the problem with single wipe sockets is in the pins themselves; if they get crushed (or stuffed) you can have pins that don't connect. they also break off, typically from corrosion. lifting the housing off will give you a better idea of how the pins look. given your game's history I would venture that the sockets are junk.

do you get any beep codes? I think if you have memory errors the game should beep. once again, not a problem on my end.

I found this the other night, it's about the most informative guide I've seen yet. http://www.kfu.com/~nsayer/games/tempest.html


No beep codes, but I do occasionally have issues with the coin counter going off by itself when I'm wiggling the pcb.
 
Looks like you may have a bad ROM, as the test mode is indicating something in the upper corner. You can try playing with the BIP pots on the game board (and maybe zoom in with the scope) to get the picture a little clearer, to see what it's indicating.

Those sockets are the crappy quality ones. They get dirty/corroded easily, as they only contact the leg in two spots (and when the chip is in the socket, it often will push or pull the pins in one direction, causing contact at only one point, and the pins to stretch out.)

You can try spreading the legs of the ROMs in or out slightly to get a little better contact with the socket pins, and you can also insert and remove the chips a few times to break up any corrosion that may be on the contact points. But if the actual ROM is bad, it won't matter. You really need either a programmer, or at least a known good set of ROMs, to act as a starting point.
 
Looks like you may have a bad ROM, as the test mode is indicating something in the upper corner. You can try playing with the BIP pots on the game board (and maybe zoom in with the scope) to get the picture a little clearer, to see what it's indicating.

Those sockets are the crappy quality ones. They get dirty/corroded easily, as they only contact the leg in two spots (and when the chip is in the socket, it often will push or pull the pins in one direction, causing contact at only one point, and the pins to stretch out.)

You can try spreading the legs of the ROMs in or out slightly to get a little better contact with the socket pins, and you can also insert and remove the chips a few times to break up any corrosion that may be on the contact points. But if the actual ROM is bad, it won't matter. You really need either a programmer, or at least a known good set of ROMs, to act as a starting point.

Thank you so much for your help. I was planning on replacing all of the rom sockets I just need to order them from mouser I have a large list of components I'm about to purchase for my major havoc blank I just received. Speaking of which would you happen to know what the proper values are for the crystals on the conversion pcb(8 or 8.96 or 9?) thank you I haven't had a chance to post in the thread yet.
 
Clean the legs of all ROMs with a wire wheel Dremel, or fiberglass brush. Then DeOxit the legs and sockets. If you have the gold dual-wipe sockets, they usually just need to be cleaned. But if they are the types that pinch the legs at two points, those are usually junk, and should be replaced.

You also ideally want to verify the ROMs with a programmer, as they easily can go bad, and relying on the self test isn't always the most reliable method.

Make sure the solder joints on the interconnect header pins have been reflowed.

Also, the Pokeys often go bad, so if you can swap them with ones from known working boards, that's a good thing to do. Also clean the chips and sockets on the aux board.

There's little sense digging deeper until you've verified the basics.

dude, that was it. those terrible sockets with the pinch pins lol I think it had those.

I wound up replacing the headers completely on ours, as I think the original ones are those terrible skinny pins. then again, I didn't change the plugs with it, but alas, that's not my problem anyway. I don't think any of that stuff is high current. but nonetheless, it's an area to check, I probably had about 6-7 pins with cracked solder. my replacements don't have friction locks, so you at least don't have to fight to unplug the boards now.
 
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