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Re: Atari TT - Bus errors, advice needed!

Posted: Fri Aug 03, 2018 3:30 pm
by Atarian Computing
Sketch (40).png
Sketch (40).png (1.01 MiB) Viewed 3784 times
Ok, so we're looking for C218 and C220. So that tells me that they are (C)apacitors like exxos said and that they are most likely in sheet two of the schematics as they start with 2. Also, your picture shows the VGA connector in their vicinity and your problems were video related. So they should appear near the VGA port in the schematics. Plenty of clues.

So I've highlighted them on the sheet and they are 150pF, that's 150 pico farads. What you want is:

Ceramic Capacitor, 150pF, Through Hole, voltage whatever 50+, axial is better here because spacing
https://www.digikey.fi/product-detail/e ... -ND/818231

Edit: They are part of the circuit to pins 13 and 14 of the VGA, so horizontal and vertical sync signals.

Re: Atari TT - Bus errors, advice needed!

Posted: Fri Aug 03, 2018 3:42 pm
by exxos
:bravo:

So he probably killed the V&H sync by the looks of it..

Re: Atari TT - Bus errors, advice needed!

Posted: Fri Aug 03, 2018 3:55 pm
by Steve
Omg thank you!!!! :)

Re: Atari TT - Bus errors, floppy issues. PARTLY SOLVED ;)

Posted: Sat Aug 04, 2018 11:36 am
by Steve
Okay guys, I've finally put her back together. I seem to have solved my problems apart from that strange bus error in the system boot log in Mint.. but all programs and games seem to be running fine. So I am just guessing I might have a software issue rather than hardware. But that can wait another day.

Thanks again to everyone who helped, special thanks to Chris and Jish.

Re: Atari TT - Bus errors, floppy issues. PARTLY SOLVED ;)

Posted: Sat Aug 04, 2018 9:52 pm
by Atarian Computing
Steve wrote: Sat Aug 04, 2018 11:36 am Okay guys, I've finally put her back together. I seem to have solved my problems apart from that strange bus error in the system boot log in Mint.. but all programs and games seem to be running fine. So I am just guessing I might have a software issue rather than hardware. But that can wait another day.

Thanks again to everyone who helped, special thanks to Chris and Jish.
Good to hear. That MiNT error is probably something I get as well on certain configurations. I know I signed off as "Jish" mistakenly but it's actually Josh, for Joshua 8-)

Re: Atari TT - Bus errors, advice needed!

Posted: Sun Aug 05, 2018 7:39 am
by Steve
Final update:

My Mint related bus error was due to either wrong or corrupted Mint kernel or extensions. I re-copied the most important files over, now the bus error log is gone!

So in summary:
* The floppy issues were solved by installing the bus SIPS as recommended
* My cracked capacitors for the video output got replaced
* The Mint issue was software, not hardware

And during the process my TT got a lot of love. Brand new vme bus pal chips, vme bus fix implemented, entire motherboard re-capped, new system fan fitted, new floppy buffer chip.

Thanks again Chris and Josh :)

Re: Atari TT - Bus errors, advice needed!

Posted: Sun Aug 05, 2018 9:31 pm
by exxos
Awesome, thanks for keeping us updated and glad you got it fixed! :cheers: