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STe LMC mixer fix for older rev board

Posted: 06 Feb 2022 17:24
by Steve
Hey guys,
@exxos kindly provided a photo of the implemented LMC fix, this is from a later revision board. Earlier revisions look a bit different
In: https://www.exxosforum.co.uk/atari/last/ ... /index.htm

STE_LMC_FIX.jpg

There are three resistors and I don't know how to exactly implement the fix for this board. Would appreciate any guidance.

PXL_20220206_172041009.MP2.jpg

Re: STe LMC mixer fix for older rev board

Posted: 06 Feb 2022 21:33
by sporniket
From the picture, I can only deduce that R526 and R532 have disappeared in later revision, others component have "survived" the revision and have kept their name.

The first thing I would do would be trying to find an early revision of the schematics that have those resistors. (it's not on the one I based my conversion)

Otherwise, I would find myself to what those resistors are connected, if it is possible.

Then once I have this alternative schematics, I would post it there to ask further guidance.

Re: STe LMC mixer fix for older rev board

Posted: 06 Feb 2022 22:02
by exxos
Maybe it was fixed in later revisions ?

STEmicrwFix.png

Re: STe LMC mixer fix for older rev board

Posted: 06 Feb 2022 22:34
by exxos
@Steve , can you lift the middle resistor so we can see what numbers it is ?

Re: STe LMC mixer fix for older rev board

Posted: 07 Feb 2022 11:38
by Steve
@exxos I lifted and it looks to me like R539

Re: STe LMC mixer fix for older rev board

Posted: 07 Feb 2022 11:40
by exxos
Steve wrote: 07 Feb 2022 11:38 @exxos I lifted and it looks to me like R539
Would assume you can just copy what's in my image then.

Re: STe LMC mixer fix for older rev board

Posted: 07 Feb 2022 12:12
by Steve
Oki doki :) here we are. Not as clean as yours because I don't have miniature resistors but should be fine :)

PXL_20220207_121116213.MP.jpg

Re: STe LMC mixer fix for older rev board

Posted: 07 Feb 2022 12:55
by exxos
Looks like there are some test programs on AF. Maybe some kind soul can download them and post them in this thread so I can upload them directly onto my web page.

Re: STe LMC mixer fix for older rev board

Posted: 07 Feb 2022 13:34
by Steve
Do you mean the TESTDMA.PRG provided by metalages?

TESTDMA.zip

Re: STe LMC mixer fix for older rev board

Posted: 07 Feb 2022 13:45
by exxos
Steve wrote: 07 Feb 2022 13:34 Do you mean the TESTDMA.PRG provided by metalages?
This was linked to AF https://www.atari-forum.com/viewtopic.p ... 50#p252373 Maybe @Cyprian Post it the software essential section for us all.