Jump to content
Due to a large amount of spamers, accounts will now have to be approved by the Admins so please be patient. ×
  • 0
IGNORED

Vector squiggles on Asteroids Deluxe


SpudJones

Question

Hi guys,

I just fixed an issue with my Asteroids Deluxe board not booting (bad LS157 at J2 had a floating line causing issues with Vector ram decoding). Anyway, after I got it booting, I found an issue with squiggly vectors as shown.

image.jpg

Any ideas? I tried replacing the TL081 and TL082 op amps in the output circuitry, but there was no change.

Paging @dezbaz @Johns-Arcade

Have you guys seen this before?

Link to comment
Share on other sites

6 answers to this question

Recommended Posts

  • 0

I see where I've gone wrong. Clearly my monitor isn't circular enough ;)

 

Seriously though, I know it's a PCB issue because if I put a plain Asteroids PCB in the same cab, then the display is fine. I'll pick up some 4016s during the week and change those on the board. Hopefully I haven't got a damaged DAC. I suspect what happened is that when the vector ram circuitry failed, something in the vector output circuits got driven beyond what it should have been.

 

p.s. interesting video about vector theory!

Edited by SpudJones
Link to comment
Share on other sites

  • 0
I see where I've gone wrong. Clearly my monitor isn't circular enough ;)

 

Seriously though, I know it's a PCB issue because if I put a plain Asteroids PCB in the same cab, then the display is fine. I'll pick up some 4016s during the week and change those on the board. Hopefully I haven't got a damaged DAC. I suspect what happened is that when the vector ram circuitry failed, something in the vector output circuits got driven beyond what it should have been.

 

Replace and socket all the IC's in the vector output section Mark, makes it a lot easier in the future. Looking at the image it doesn't look like a DAC issue to me.

 

Regards,

 

Johns-Arcade.

Link to comment
Share on other sites

  • 0
Replace and socket all the IC's in the vector output section

 

As expected, it ended up being one of the CMOS 4016 ICs in the vector output section. (and all socketed now!)

Working nicely again!

 

Hopefully it will cool down enough that I can play a few games in my garage with a couple of cold beers! :)

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...