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Does anyone have an early revision CreatiVision they can photograph the PCB for me?
Posted: Thu Apr 13, 2023 12:18 pm
by cheshirenoir
I'm trying to make sense of my PCB around the VDP clock generator area and I'm starting to think some components have been removed as there are traces that just go nowhere.
This is the top right corner.
If you could take a photo top and bottom of your board of the same revision, I can work out if the board has been badly modded, I've gone mad, or the original designer was mad.
(I literally have tracks going nowhere, and another track that travels across the underside of the board, pops up to the top side of the board, then back the way it came, parallel to the original track. Why?)
John
Re: Does anyone have an early revision CreatiVision they can photograph the PCB for me?
Posted: Thu Apr 13, 2023 3:05 pm
by Scouter3d
Hi Chesh,
here are some pics for comparison...
Cheers, TOM:0)
20230413_165715.jpeg
20230413_165709.jpeg
20230311_142329 1.jpeg
Re: Does anyone have an early revision CreatiVision they can photograph the PCB for me?
Posted: Thu Apr 13, 2023 3:07 pm
by Scouter3d
But mine looks like a bit different revision...
PS: have you checked for bend pins/shorts on the cartridgeport / Joystickports? - Just an idea, but it should be rather sturdy
Re: Does anyone have an early revision CreatiVision they can photograph the PCB for me?
Posted: Thu Apr 13, 2023 10:11 pm
by cheshirenoir
No that's perfect! I think I can see what's going on with mine now. And that photo from the bottom shows the second inductor that I couldn't find on mine. Brilliant.
(My current issue is the clock circuit isn't going into resonance, so the TMS isn't getting a clock. I think someone had been "playing" and your photos prove it)
Re: Does anyone have an early revision CreatiVision they can photograph the PCB for me?
Posted: Sun Apr 16, 2023 3:59 pm
by Mobsie
Hi, how is going? any positive update?
Re: Does anyone have an early revision CreatiVision they can photograph the PCB for me?
Posted: Mon Apr 17, 2023 3:03 am
by cheshirenoir
Haven't had much time to do anything more than do a "map" of the PCB in the area.
Tempted to desolder everything in the area, reflow all the VIAs, and then carefully repopulate it as per the schematic, component by component.
Re: Does anyone have an early revision CreatiVision they can photograph the PCB for me?
Posted: Mon Apr 17, 2023 11:20 am
by Scouter3d
PS: Did you try another TMS9929?
Or if the VDP-Clock is ticking with the TMS removed?
Cheers, TOM:0)
Re: Does anyone have an early revision CreatiVision they can photograph the PCB for me?
Posted: Sat Apr 22, 2023 3:33 am
by cheshirenoir
OK, I'm back. Been on a week long cruise to see a total eclipse.
(Totally worth it)
OK so the VDP clock is not ticking even with the 9929 removed. (I think. It's been a long week. I'll check once I have had a proper night's sleep)
I have another 9929 on order.
John