Interesting find regarding GCVideo

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Xaranar
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Interesting find regarding GCVideo

Post by Xaranar » Tue Nov 03, 2015 11:01 pm

So for the past few weeks I've been tearing my hair out trying to work out why my Wasp would intermittently not work. I initially thought it was damaged FFC cables, but after replacing them, sometimes the Wasp simply wouldn't power up properly. It's then I discovered that occasionally, when powering off my cube, my Pluto board would retain power, as one of its LEDs would remain lit. This power was actually being drawn from the HDMI cable itself, as the light would go off after unplugging the cable. Anyway, if the Pluto board retains power after the unit is switched off, when switched back on again, the Wasp will not initialise properly. This can be remedied by simply unplugging the HDMI cable and plugging it back in again, but I thought it relevant to post my findings here.
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megalomaniac
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Re: Interesting find regarding GCVideo

Post by megalomaniac » Wed Nov 04, 2015 12:39 am

nothing to do with GCVideo, and most likely related specifically to your semi-defective, low quality assurance, board...
viewtopic.php?p=32548#p32548



this reminds me, didnt you post something about screen wobble or something
you were having some overall general issues with HDMI?
i bet your board has been defective in some way this entire time...
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Xaranar
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Re: Interesting find regarding GCVideo

Post by Xaranar » Wed Nov 04, 2015 6:57 am

megalomaniac wrote:nothing to do with GCVideo, and most likely related specifically to your semi-defective, low quality assurance, board...
viewtopic.php?p=32548#p32548



this reminds me, didnt you post something about screen wobble or something
you were having some overall general issues with HDMI?
i bet your board has been defective in some way this entire time...
I did, yes, but the wobble was only present on that monitor. Well Mega, you had better get your shit together and sort out your GCVideo solution for us hadn't you! Shut up and take my money! :P
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megalomaniac
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Re: Interesting find regarding GCVideo

Post by megalomaniac » Wed Nov 04, 2015 9:28 am

Soon
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meneerbeer
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Re: Interesting find regarding GCVideo

Post by meneerbeer » Wed Nov 04, 2015 10:19 am

Xaranar wrote:So for the past few weeks I've been tearing my hair out trying to work out why my Wasp would intermittently not work. I initially thought it was damaged FFC cables, but after replacing them, sometimes the Wasp simply wouldn't power up properly. It's then I discovered that occasionally, when powering off my cube, my Pluto board would retain power, as one of its LEDs would remain lit. This power was actually being drawn from the HDMI cable itself, as the light would go off after unplugging the cable. Anyway, if the Pluto board retains power after the unit is switched off, when switched back on again, the Wasp will not initialise properly. This can be remedied by simply unplugging the HDMI cable and plugging it back in again, but I thought it relevant to post my findings here.
I have a board that is very similar to the Pluto IIx hooked up to my N64 and I am having a very similar problem. Both my HDMI board and Everdrive will not power up correctly unless I first replug the HDMI connector. I have yet to further look into this problem, as I am looking into adding more functionality rather than fixing bugs/problems.

I should give the board a try on the Gamecube to see if it happens there as well, so I can rule out if it is a soldering mistake.

But it indeed seems the HDMI plug is providing the board with power and I think the rest of the system gets power as well because of that. I think that is why your WASP fails to boot up correctly, but do not quote me on that.
Xaranar
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Re: Interesting find regarding GCVideo

Post by Xaranar » Wed Nov 04, 2015 11:16 am

I'm going to try reflowing the pins on the HDMI connector when I get home from work. I doubt it'll make any difference, but it can't hurt to try.
andre104623
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Re: Interesting find regarding GCVideo

Post by andre104623 » Wed Nov 04, 2015 11:44 am

Xaranar wrote:I'm going to try reflowing the pins on the HDMI connector when I get home from work. I doubt it'll make any difference, but it can't hurt to try.
I have pluto hooked up to my wasp gamecube and i don't have any problems with that setup. Like mega has stated the pluto has issues with quality control and for that reason you cant rule out defects. How long are your wires by the way
Xaranar
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Re: Interesting find regarding GCVideo

Post by Xaranar » Wed Nov 04, 2015 3:46 pm

My wires are only about 3" long, and it's a shame the board has quality control issues, as otherwise it's pretty decent.
meneerbeer
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Re: Interesting find regarding GCVideo

Post by meneerbeer » Wed Nov 04, 2015 8:56 pm

I had a short look at my board that is giving the same problem. As said, it is hooked up to an N64. When I turn off the N64 and I still have the HDMI cable plugged in, I measure 1.40 V on my 3.3 V power line. When I unplug the HDMI cable it goes back to 0.0 V. I do not know what causes this problem and I have not looked any further yet. I think the low voltage can make the FPGA lose its configuration.

I have not hooked up the 5 V line, so my HDMI connector also does not have +5 V on the DDC pin. Did you add the 100 Ohm resistor to your Pluto IIx board?

I should really try a board, that is known to work correctly, on the N64, that will rule out a lot.
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Unseen
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Re: Interesting find regarding GCVideo

Post by Unseen » Wed Nov 04, 2015 9:49 pm

meneerbeer wrote:When I turn off the N64 and I still have the HDMI cable plugged in, I measure 1.40 V on my 3.3 V power line. When I unplug the HDMI cable it goes back to 0.0 V. I do not know what causes this problem and I have not looked any further yet.
The cause is probably current fed from some of the HDMI signal pins through the FPGA to the 3.3V line. Assuming that there are no unintentional shorts on the PCB (big assumption, I know...) the only obvious candidate signals I can think of are DDC-SDA and DDC-SCL, although they should have relatively weak (10k or so) pullups on the display side. Both of them are not used by GCVideo at all.
I think the low voltage can make the FPGA lose its configuration.
It's probably in a "not really working, but not completely losing the config either" state and doesn't resume or reset correctly when the real power supply is back again. On a microcontroller I would solve that by turning on brown-out detection, but unfortunately that's not a standard feature for FPGAs.
I have not hooked up the 5 V line, so my HDMI connector also does not have +5 V on the DDC pin.
That would've been my first guess for the power source and it would be easier to solve - a BAT85 diode (the common 1N4148 may or may not work here) instead of the 100 ohm resistor, with the cathode (ring marking) towards the HDMI connector would prevent that problem.
Asking for support by PM is anti-social. Ask in an open forum instead, so other people can benefit from the answers!
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badsector
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Re: Interesting find regarding GCVideo

Post by badsector » Tue Apr 16, 2019 3:13 pm

I stumbled upon this post after trying to find out what went wrong with my freshly modded Cube (Pluto and WASP) and I got the exactly same problem. Did anybody find a working solution for this somehow?
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