Gorf Misbehaving

[ataridude74]

My Gorf has started to have issues, and they have got worse.

First it was:

• Top corner of screen in Astro Battles (Space Invaders one) was black, not blue
• Video jittering, and vertical roll which was worse on certain levels

Then today:

• Alien sprite corruption on Galaxian screen, a smeared mess where previous positions were not cleared
• Speech repeating itself

And finally, at which point I switched it off:

• Mid-game reset to title screen
• Low level high-pitch continuous beep

I am hoping it's not a custom chip going bad, the 'sparkle' effect is still present and sprite colours are correct. The Laser Attack screen in particular has solid video with no graphic or jittering issues.

Maybe a bad RAM, CPU or pattern board? I have a spare set to swap out boards, but before I dive headlong into the rabbit hole - any suggestions? (other than wait for Mike's FPGA solution!)

 

[patzik]

There is a test rom for gorf, I would try that first.

 

[bones]

As above first, obviously check the PCB everything plugs into for bad solder joints. Hopefully it's just a bad connection somewhere amongst the many connectors.