A3000 Screen Issues (Amber?)

[madgrizzle]

Since I kentucky-fried my VA2000, I want to see if I can just use the 3000's native graphics modes.  I understand the 3000 has a built in scandoubler and flicker fixer and I'm having a bit of an issue with it.  With the switch in the back turned off, I get a clean screen but lots of flicker on my Dell 2240L monitor.  With the switch turned on, I get issues.  Screenshot below.  

Any suggestions on where to start looking to get this fixed?  I know I have some issues with Denise.. it doesn't sit really well in the socket (there was lots of battery corrosion I had to clean up and maybe I cleaned up too well).  I have to press on her sometimes to get her to seat correctly.  But no amount of pressing/adjustment has improved the screen beyond this point.

[madgrizzle]

I actually know very little about the 3000 and wasn't sure what that thing "adjusted"  I was hesitant about changing something and wasn't sure if that adjustment would help my particular issue (why I posted an image).  If it doesn't harm anything, I'll give it a shot.

[madgrizzle]

Thanks, it has a procedure for tweaking.. Will try tonight.

[madgrizzle]

Neither the fine adjustment or the course adjustment fixes the problem.  When I switch to DBLNTSC, I get a nice steady image, but I'm limited to 4 colors in that mode.  I was hoping to get NTSC 640x400x16 (interlaced) working with the built in deinterlacer, but it's having issues.  I pushed on all the components around Amber (and reseated Amber) and nothing seemed to make any sort of difference.

I posted a short video of it to youtube.
https://youtu.be/RdYu9Gyn2Y8

I'm wondering if there is a problem with the framebuffer.   But there's also a distinct ghosting.. All icons and mouse have a ghost shifted about 50? pixels to the right..

[madgrizzle]

You could admit defeat and send it to Acill :lol:

Yes, not quite there yet.  I was hoping someone that saw this could perhaps give me a lead to where to focus.  My theory is that its not a Denise problem because its only there when I try to deinterlace.. and that's an Agnus responsibility.  The screen is rock solid in "DBLNTSC:High Res No Flicker" which outputs 640x400 but obviously bypasses the deinterlacer.

BTW dude... Never, ever, ever sell or lose your PCD-50B!!!

Never!  It's the greatest thing since sliced bread.

[madgrizzle]

You might pull the motherboard out completely and go over all the traces, component connections, solder joints... etc. with a fine tooth comb. After that, an O'scope might come in handy.

I think I will do that.. I noticed looking at the schematics that U480 and U477 are real close to the battery.. so there may have been some corrosion issues there.

[madgrizzle]

I've been able to greatly improve the screen output with the deinterlacer turned on, but I still am having a problem in the lower portion.  The yellowish lines in the picture are not steady (they flick in and out at different places) and on the left side of the screen, they seem to be "double" the amount within the first 10 percent or so.  Basically, there's twice as many yellow lines in the first column of icons as the rest of the screen.

I am wondering if this might be a chip problem since it seems to affect only a portion of the screen.  Any ideas?

[madgrizzle]

Does this work?
https://drive.google.com/open?id=1lD6OeRae_kOF3PeQnJdVM6-CluBg3Xds

[madgrizzle]

If I set the background to yellow, the lines yellow lines fade into it, but I can make out a flickering of blue.  The difference between the yellow and blue lines are that the yellow lines seem random in position, but the blue lines seem to have a pattern... attached is a representative drawing of the lower portion of the screen.  The blue lines weren't there at first, they sort of developed over time as the computer ran.. becoming more and more pronounced.

https://drive.google.com/open?id=1JaSzs8oFgYqLhqwg4TcsiekvYQ_Msqgd

Edit:  When I set the background to black, I get blue streaks all over the screen.  Technically, I would think I shouldn't get any blue if the color is black so that suggests maybe something wrong with the blue delay line?

[madgrizzle]

No difference switching to two-color (other than the obvious two-color scheme).  Still have streaks.  I've taken a video of the black background and the behavior of the blue streaks and posted to youtube:

https://youtu.be/cG0QlDqabPk

And sorry about the images.. I had done a quick reply and there was no option to add an attachment, just embed a picture.. and embedding a picture required a url.  I see if you do a regular reply, you get a more capable editor where you can add the attachments.  So, here it is:

[madgrizzle]

Well, I know I need a new amber now, regardless of it being the problem or not.  Pulled it out to reseat it and must have buggered it up doing so because one of the pins broke.  Sigh...

And yes I was using a PLCC puller...

[madgrizzle]

Am I correct in assuming that an A2320 would work in an Amiga 3000?  It plugs into the video slot and I assume uses no drivers.  Also, am I correct in assuming that the Indivision ECS bypasses the amber circuitry entirely and so would work in an A3000 without a functioning amber?

[madgrizzle]

Thanks.  They will be making more Indivision ECS later this year and, because components aren't made anymore, they won't be available at their previous price.  I saw one go for $170 recently but I can get another VA2000 for $50 more.. and its an RTG board.

At least it boots without a working amber and I can use a GBS8200 to see the screen.