520ST stuck in MONO mode

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PhilC
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Re: 520ST stuck in MONO mode

Post by PhilC » Sat Apr 17, 2021 7:38 pm

@rubber_jonnie yes, absolutely fine on other STs.
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Re: 520ST stuck in MONO mode

Post by exxos » Sat Apr 17, 2021 8:14 pm

Do you have 12v on the RGB port ?
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Re: 520ST stuck in MONO mode

Post by PhilC » Tue May 04, 2021 3:50 pm

exxos wrote:
Sat Apr 17, 2021 8:14 pm
Do you have 12v on the RGB port ?
SO I had a few mins to look into this. This ST doesn't have 12v going to the monitor port by design and instead uses a 5v pullup arrangement for the mono mode selection.
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Re: 520ST stuck in MONO mode

Post by exxos » Tue May 04, 2021 3:58 pm

PhilC wrote:
Tue May 04, 2021 3:50 pm
SO I had a few mins to look into this. This ST doesn't have 12v going to the monitor port by design and instead uses a 5v pullup arrangement for the mono mode selection.
Yeah normally like 10K to 12V pullup on the MONO pin.
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?

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Re: 520ST stuck in MONO mode

Post by PhilC » Tue May 04, 2021 4:00 pm

@exxos I'm actually wondering if its the VGA adaptor that doesn't work, so will make up a start cable to try it at some point.
If it ain't broke, test it to Destruction.

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Re: 520ST stuck in MONO mode

Post by exxos » Tue May 04, 2021 4:05 pm

PhilC wrote:
Tue May 04, 2021 4:00 pm
@exxos I'm actually wondering if its the VGA adaptor that doesn't work, so will make up a start cable to try it at some point.
I do test mono / RGB switches.
https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?

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Re: 520ST stuck in MONO mode

Post by PhilC » Tue May 04, 2021 4:17 pm

exxos wrote:
Tue May 04, 2021 4:05 pm
PhilC wrote:
Tue May 04, 2021 4:00 pm
@exxos I'm actually wondering if its the VGA adaptor that doesn't work, so will make up a start cable to try it at some point.
I do test mono / RGB switches.
Of that I have no doubt. I've got lots more in the queue in front of this right now, re a V5 as you know :D
If it ain't broke, test it to Destruction.

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