Tempest - Misalignment

Wish

Well-known member

Donor 2011
Joined
Jan 24, 2009
Messages
1,422
Reaction score
627
Location
Phoenix, Arizona
I finally got my Tempest back yesterday and the repair place got my monitor back up and running, but there is still a display issue where the lines of the game grids are off.

All the words display ok, it's just the game play that is off.

The repair place said this is a board issue and they wanted to send the boards off for repair, but I thought I'd ask here first on what the likely issue is, and try to figure out my best option.

Here's a video showing the attract mode, but you can see the problem when it demos the game....all game levels have the similar issue.

Anyways...I'm getting closer to having a working Tempest!!!!

 
Give us a vid, or screen shot of it in test mode, preferably the diamond pattern.

The Aux board does all the math for the vectors in game mode, so I'm not expecting to see a problem in Test mode.

Could be a loose 2901, or cable. Do you get a "M" in test mode?
 
Hey...thanks for helping me out. :)

Yes, there is an "M" in test mode.

Here are a few pics.
 

Attachments

  • DCP_0542.jpg
    DCP_0542.jpg
    98.5 KB · Views: 47
  • DCP_0539.jpg
    DCP_0539.jpg
    93 KB · Views: 34
  • DCP_0540.jpg
    DCP_0540.jpg
    99.9 KB · Views: 32
  • DCP_0545.jpg
    DCP_0545.jpg
    96.9 KB · Views: 31
I read a little bit about the "M" error today...that was a good tip.

So please excuse my newbieness on Tempest repairs...but this is my understanding of where I am at.

The "M" error code means a problem with the math box.

It could be related to the interboard cable/connectors or those bit slice/transistor chip thingies.

Is that correct?

What would be my best course of action with zero experience with video game repairs and no circuit board soldering skills? :rolleyes:
 
Try removing the boards from your cabinet then disconnecting the interconnect cable and reseating it once or twice to scrape away any light corrosion. You could also (carefully) remove any socketed ICs on the Tempest AUX Board (small one) and reseating them. Do only one chip at a time and make note of the original orientation of the ICs so they are reinstalled in the same direction.

You may get lucky.


Your AVG circuit appears to be fine based on the self test pictures and so does at least some of your vector ram and rom. The tube lines are drawn dynamically and not from pre-rendered objects in rom so the mathbox comes into play.
 
This issue may be as simple as reflowing the solder on the interconnect pins. Gently seperate the two boards and look for hairline cracks around your pins. That is all it takes to mess up the graphics on a tempest. If that is the case simply reheat the pin with a electronics style 25watt solder iron on the solder side of the board and add a small amount of non acid solder to each pin. Do not overheat the pins or short two pins together. Put it back together put the wire interconnect back on the pins and see if this fixes the problem.
 
I agree with both previous posts. Reseat the chip and cable while checking the cable headers for cold solder joints. I've seen both of these issues result in a mathbox error. The only thing I'd add is that the cable itself can be the culprit.

If neither of these solutions work, start looking at the bit slicers. Get a known good one and swap it out for each of them on your board in turn. You'll figure it out!
 
Thanks guys.

I pulled the boards and took a look. I did not see any cracks around the pins...and briefly thought about trying to reflow the solder, before coming to my senses, and realizing that those pins are much to close together for my extremely limited soldering skills and I'd probably get too much solder on and short the pins together! :p

So I reseated the interconnect cable, and put the boards back in and fired the machine up...that did not fix the problem....it's still there.

So does anybody know who does repairs on the math box board? Or should I try to get a replacement interconnect cable first?
 
The cheapest I've seen for repair is 85 bucks, + shipping, plus fear of the UPS guy breaking the board in half :(

I'd *seriously* reconsider reflowing the pins... practice on something else if you have to...

if all else fails, do a "poor man's" reflow and heat the existing solder with with a touch of new solder. It's not optimal, but may save you 100 bucks or so.
 
Oh man....you guys are gonna make me learn to solder, aren't you??!?!?!?

:D

I'll see if I can give it a shot later today. Ugh. :eek:

*keeps fingers crossed to not make things worse*
 
Alright...I took a shot at reflowing the solder on the pins. It wasn't pretty, but did give me a little experience. I practiced a little on an old pinball circuit board first. Desoldering braid is my friend! ;) I did end up soldering multiple pins together. Desoldering braid is my friend! ;)

The good news is I didn't make anything worse.

The bad news is that it didn't fix the problem.

I don't think I want to try removing chips at this point. Sending it out for repair may be my best option.
 
Good Luck

Well, full credit for effort, and my respect for using desoldering braid ... I could never make that stuff work. While I'm on the subject, the only thing that keeps me in this hobby is my Hakko 808 desoldering gun. If I had to use braid, I'd just take up golf :)

Please report back with the solution to your problem -- it's really useful to have a symptom and a solution in the same thread!
 
Ok...I was confused on removing the chips....I was thinking I would have to de-solder them and then resolder them back in.

But then I figured out that a bunch of the chips have a socket and could just be pried out and then reinserted - no soldering necessary. :)

So I removed and reseated the chips that were in sockets.

Re-started the game, and the problem is still there.

So are the bit slicer chips in one of the removable sockets and can I just buy some replacement chips and drop them in? Or do those chips require soldering?

What's my best option at the moment? New interconnect cable? New bit slicer chips (where do I get them?)?

Whaddaya think?
 
New bit slicer chip thingies have been ordered and are on the way to my house!!!

Was that too technical?

:D

I wonder if I will have a working Tempest by the upcoming weekend?

:confused:

:cool:
 
And in this picture below, there is a line hanging down from the middle white cylinder. Is that another problem? :eek:

I saw someone else posted the same screen and their picture didn't have that line hanging down.

I sure hope it's not gonna be another issue to deal with after the bit slicer replacements.

:rolleyes:

I want a working machine dagnabbit. :p
 

Attachments

  • DCP_0540.jpg
    DCP_0540.jpg
    99.9 KB · Views: 21
:mad:

So the bit slicer chips arrived today (thanks channelmanic..that was super fast! :)).

I installed them...and I've still got the same problem as shown in the video in the first post.

Talk about being bummed!!!! :(

I was really hoping that would fix it.

So does anyone have any ideas on what my next steps should be?

And I'm not opposed if that next step is sending the board out for repair. That might be the best thing in my case with my limited experience and repair skills.

Whaddaya think?

What the heck is wrong with this thing?

Help!!!

:cool:
 
Back
Top Bottom