800xl Red Screen. I want to fix!

[800xl Red Screen. I want to fix!]

I don't get it - you ordered all of those chips without knowing which one is faulty?

 

You have a display (albeit red screen) which means GTIA at least can do that much.

If the screen is steady (non-rolling) then it means Antic is sending VSync commands and is at least partially functional.

 

Given you also have a good machine and the skills for solder/desolder it would have been an idea to do the one at a time testing.

I see your point, but at the end of the day I would like to get this machine up and running. So I will ultimately need more chips. There is a minumum order of $20. I think its a small price to pay to hopefully bring this mobo back from the dead. I am tempted to start swapping chips back and fourth, but I worry that I could do harm to the other working system. It's a possibility right?

 

FYI The display is steady red.

[800xl Red Screen. I want to fix!]

and safer! I always test the chips one at a time from the bad unit being put into a good unit, it prevents killing good chips!

Yes! Like the sound of that. Good common sense! Thanks.

[800xl Red Screen. I want to fix!]

Hi Guys,

 

Ok so firstly, thanks for all your input so far. As you can see from the image I have fitted sockets to the GTIA, ANTIC and CPU. I spoke with ( and I have forgotten his name ) the guy from Best Electronics who was super nice, and very knowledgeable the same as you guys. We thought we would start with the cpu and move on from there. I have all three of these socketed chips coming - should be about two weeks.

I will keep you all posted!

Of to grab a cold one now - even though it's -10c out. Cheers!!

 

[800xl Red Screen. I want to fix!]

Hi Guys, thanks for the valuable input. I just replied to your comments but it didn't make it to the forum for some reason - so here goes again.

 

As soon as I soldered in the last of the memory chips, the thought occurred to me that I should have socketed them! Doh! You live and learn. I assumed ( incorrectly as it turns out ) that all the 800xl's had soldered IC's. I have a fully operational 800xl here also. I lifted the hood, and it does have ALL socketed IC's - see image. So, I have the option of using these known good IC's for testing I spose. Doesn't make me feel any better lol. Don't fancy my chances of removing a bunch of them without breaking something.

 

So, what would be the best way to go about this? If I can remove the IC's from the bad board without any damage to the chips, I can do this one at a time and add a socket then swap them over to see if it will bring the bad board back to life.

 

I suppose that would be the way to do it. If you had to chose an order of which chips to desolder first, what would be your best bet? lol. It would make sense to try and minimize the work/disruption/potential damage with this approach no?

 

I assume I can pick up sockets and any good electronics outlet?

 

 

It's getting late, been a long day. Need to sleep on this one.

 

Thanks again guys.

 

 

 

 

 

 

 

[800xl Red Screen. I want to fix!]

Hi everyone.

 

I recently picked up an 800xl that on the outside looks mint, but upon power up it displays a red screen and that's it.

 

So, reading on here and other forums around the net, the first culprit appeared to be the memory - a couple of chips were indeed almost too hot to touch, so I sourced and replaced all 8 ( 4264-15's ).

Now when the system is powered up the ram chips all run at a cool temp - way cooler than before. But, still the red screen. So I have scoured the forums trying to get some pointers as to what to try next.

 

If I leave the system running for a few minutes, the top right chip becomes hot - I beleive that is the BASIC ROM, it's marked C024947A-01. I also understand that sometimes the ANTIC and GTIA chips can also fail ( these being the chips tasked with correct display? ).

 

Has anyone had any success with tracking down the cause of the RED screen of Death and resurrected an 800xl successfully? If so, any pointers as to what fixed it? I am happy to work through this, report my findings to help others, and get this clean machine back operational again. If I wanted to source replacement chips here in Canada/US where would I start? Best Electronics?

 

Anyway, any advice would be appreciated.

 

Damian.