daver2
10k Member
There be glitches there!
Can you scope pins 4 and 8 of IC305 to see what is going in to that IC please.
Dave
Can you scope pins 4 and 8 of IC305 to see what is going in to that IC please.
Dave
It probably can be repaired--there's an image. As to what the exact problem might be--it could be something as simple as a bad pot, or considerably more involve.
Congrats! I still have the one I bought new, in the box. I picked it up on clearance after Vectrex went out of business and grabbed the light pen, and a lot of games. Sadly some parts got lost over the years, but it still works and I still have the games in their boxes with their screen cards. Fun machine.Good evening guys,
I'm about to buy a vectrex console that has a defect in the screen (as in the photo)...
do you think it can be repaired? It appears that the image is shifted all the way to the right and is compressed ...
Thanks so much!
Ok have a nice evening!They look Ok.
Could you scope pin 5 to see what is going on there as well please.
I am going out now for the rest of the evening, so I will have a think tomorrow about where we go next (based on what I see in your video of course).
Dave
Good morning Dave,If there is no flux residue on the solder side of the PCB around the pins of IC305 I am suspecting IC305 is in need of replacement.
All of the signals going into the IC switch are clean, but what is coming out is noisy. The two (2) outputs from IC305 (on pins 3 and 9) go through 2 off 10k resistors, so there shouldn’t be any ‘noise’ or ‘glitches’ feeding backwards from the OPAMPS.
That’s my best guess anyhow.
Dave
Hi Dave, yes i think this..... before changing the old IC i had always glitches and now not!The other possibility is that by changing the IC we have fixed another (but unrelated) fault we didn’t know we had?!
it takes a lot of patience and Dave has a lot of patience with meHats off for staying with this for 355 posts! I did warn way at the beginning that old CMOS ICs did appear to fail more frequently than one would expect. It could be that the process wasn't mature enough, but I've certainly run into my share.