1040 STF showing occasional rogue pixels

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exxos
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Re: 1040 STF showing occasional rogue pixels

Post by exxos » Wed Oct 03, 2018 6:12 pm

sandord wrote:
Wed Oct 03, 2018 6:10 pm
If only we didn't have the 50% RAM speed problem :cry:
You broke that bit :P You must have created a bad solder or broke something last solder session as it wasn't doing it before...
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Re: 1040 STF showing occasional rogue pixels

Post by sandord » Wed Oct 03, 2018 6:16 pm

exxos wrote:
Wed Oct 03, 2018 6:12 pm
sandord wrote:
Wed Oct 03, 2018 6:10 pm
If only we didn't have the 50% RAM speed problem :cry:
You broke that bit :P You must have created a bad solder or broke something last solder session as it wasn't doing it before...
Yeah, I'm really willing to admit that. If only I could find evidence! Looks all clean and I didn't heat anything for longer than a second or two. Going to look into it further tonight.

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Re: 1040 STF showing occasional rogue pixels

Post by sandord » Wed Oct 03, 2018 7:08 pm

exxos wrote:
Wed Oct 03, 2018 10:47 am
...I would solder a wire over L51 (next to PSU connector) and see if that does anything.
I'm going to buy you a beer for that one :dualthumbup:

By the way, is L51 some sort of anti-interference filter? Is it possibly creating noise instead of reducing it in our case?

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Re: 1040 STF showing occasional rogue pixels

Post by sandord » Wed Oct 03, 2018 7:13 pm

sandord wrote:
Wed Oct 03, 2018 7:08 pm
By the way, is L51 some sort of anti-interference filter? Is it possibly creating noise instead of reducing it in our case?
Taking a closer look, I think it is a resistor! But why is it so bulky?

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Re: 1040 STF showing occasional rogue pixels

Post by exxos » Wed Oct 03, 2018 9:19 pm

sandord wrote:
Wed Oct 03, 2018 7:13 pm
Taking a closer look, I think it is a resistor! But why is it so bulky?
If the image your posted was your board, you can see the wire on it. Some do look like a resistors... "L" is Inductor.

I noticed I bridged over the same inductor on a C070789-rev F board at some point.. Looks like I added a extra 1MB and must have had issues with the RAM to bridge over it.. must have been some years ago. Likely voltage drop to much across it to power the full 1MB.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

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Re: 1040 STF showing occasional rogue pixels

Post by sandord » Wed Oct 03, 2018 9:25 pm

exxos wrote:
Wed Oct 03, 2018 9:19 pm
If the image your posted was your board, you can see the wire on it. Some do look like a resistors... "L" is Inductor.

I noticed I bridged over the same inductor on a C070789-rev F board at some point.. Looks like I added a extra 1MB and must have had issues with the RAM to bridge over it.. must have been some years ago. Likely voltage drop to much across it to power the full 1MB.
Yeah, the picture is from our board. There are coloured rings on the inductor, brown-black-black-silver so that's why I thought it was a resistor.

IMG-20181003-WA0001.jpg
IMG-20181003-WA0001.jpg (297.8 KiB) Viewed 145 times

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Re: 1040 STF showing occasional rogue pixels

Post by exxos » Wed Oct 03, 2018 9:29 pm

sandord wrote:
Wed Oct 03, 2018 9:25 pm
Yeah, the picture is from our board. There are coloured rings on the inductor, brown-black-black-silver so that's why I thought it was a resistor.
Yours does look like its got markings on it.. I never seen one like that (with colours) but have seen the wire inductors for a long time in use.

The one I looked at just looks black blobby, like cheap manufacture job... No real markings on it.. possible it could have burnt off over the years..

This was my board...

IMG_3283.JPG
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4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
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Re: 1040 STF showing occasional rogue pixels

Post by sandord » Thu Oct 04, 2018 4:39 pm

After resoldering the buffers for the second time:
:cheer: :cheer: :cheer:

IMG-20181004-WA0003.jpg
IMG-20181004-WA0003.jpg (68.75 KiB) Viewed 116 times

Thanks Exxos and everybody else for your suggestions! And thanks everybody for bearing with us ;-)
I'm glad we didn't replace the RAM, probably wouldn't have helped and surely would've been a waste of money!

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Re: 1040 STF showing occasional rogue pixels

Post by exxos » Thu Oct 04, 2018 5:01 pm

sandord wrote:
Thu Oct 04, 2018 4:39 pm
Thanks Exxos and everybody else for your suggestions! And thanks everybody for bearing with us ;-)
I'm glad we didn't replace the RAM, probably wouldn't have helped and surely would've been a waste of money!
Excellent! Thanks for keeping us updated! :thumbup:

So we can rule it as "curse of the toy inductors" then!
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
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Re: 1040 STF showing occasional rogue pixels

Post by sandord » Thu Oct 04, 2018 5:38 pm

exxos wrote:
Thu Oct 04, 2018 5:01 pm
sandord wrote:
Thu Oct 04, 2018 4:39 pm
Thanks Exxos and everybody else for your suggestions! And thanks everybody for bearing with us ;-)
I'm glad we didn't replace the RAM, probably wouldn't have helped and surely would've been a waste of money!
Excellent! Thanks for keeping us updated! :thumbup:

So we can rule it as "curse of the toy inductors" then!
I'm crying right now. Metrocross is showing bad pixels again. I guess that the wire made the ST only stable at half speed...

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