[Weird issue fireing when not pressing fire]

I would have suspected the sound chip (which also handles button inputs for both controllers), but you say Mine Storm works OK. I don't quite understand the boot issue you describe. A video would help.

 

BTW, you can only shoot while moving in Berzerk, which is why it doesn't happen when still.

[Screen Problem while displaying characters]

Someone on FB just fixed a similar issue by replacing the 6522 VIA.

[Misaligned vectors]

OK, thanks.

[Misaligned vectors]

A bit more information. I discovered that putting finger pressure on poly cap C305 has an affect on vector alignment. i.e makes it even worse, and skews text slightly, too.

[Misaligned vectors]

30 minutes ago, gtoal said:

The VIA is the 6522 which is effectively the vector generator on this machine. different models may have marginally different timing, and Clean Sweep is such a hack that it is extremely sensitive to timing differences.

 

Ah, useful information. Thanks.

 

Now you've pointed out the 6522, it's possible it has been replaced, as it looks very clean (see pics). Difficult for me to tell though, as the whole PCB is pretty clean, in general. Can you tell by the marking on it?

[Misaligned vectors]

I've only just got this Vectrex, so haven't changed anything. The previous owner did the re-cap. Looking closer at the PCB, only the AY sound chip looks like it may be a replacement, but I assume this wouldn't affect the vectors. I watched a vid where a chap fixed a vector issue (albeit a bit different to mine) by replacing the socketed LF347N IC, so I will probably try that.

 

Sorry, what/where is the VIA? New to all this.

 

Cheers.

[Misaligned vectors]

My Vectrex seems to have some issue with vectors being misaligned, or not joining together. This is most noticeable with the corner rooms in Clean Sweep (see pic).

I watched a couple of vids of the game and all the vectors there seemed to line up almost perfectly. Any ideas on what the problem could be?

 

I've run through the test cart and adjusted so everything looks good, except for distortion test 1 - all the triangles around the screen wobble (don't know if this is normal). Vectrex has been fully re-capped, BTW.

 

Cheers

 

 

 

[DAC offset query]

Thanks for the explanation. I've found the manual PDF and will print it out to have a good read through.

[DAC offset query]

This is my first post here, so first of all, hello everyone!

 

I'm due to take delivery of my first Vectrex soon - a console I've always fancied owning. I love vector games! Anyway, on to my question...

 

I've seen mention of resetting the DAC back to zero, but can't find what doing this actually does! There's even a vid on YouTube showing how to do it, using a test cart and multimeter, but fails to mention the reason for making the adjustment.

 

Can someone enlighten a Vectrex noob, please?