Hitachi 27MM20B GC Video HDMI and Chromecast issues

[ganglyman]

Hello! I just got one of these sweet Hitachi monitors and wanted to hook up my GC video hdmi gamecube and Chromecast w/ Google TV i just got. I tried plugging each of them in thru the Tendak HDMI to VGA converter but my tv isn't recognizing the signal from either source. Both are set to output in 480p (the GC is 720x480 and I assume the Chromecast is the same). The tv wants to do 640x480 though. I have an OSSC as well. What easy options do I have to get these working? Any help is much appreciated, thanks!

[Hoagtech]

This is my brother posting this btw. I assumed you can input HDMI through a DAC like Tendak in AV3 on the OSSC but it did not work.

If anyone has suggestions on going from digital sources without downconversion, I would love to know as well.

He’s using GCvideo into 480p on the Hitachi

[strayan]

If the tendak needs power gcvideo won’t power it.

Try another externally powered hdmi to vga comverter. I’ve had issues with other hdmi to vga converters and 31khz CRTs (I suspect in my case it was a GTF or CVT timing issue). I ended up using an old externally powered DVI to VGA box. This was years ago so newer gcvideo firmware/firmware settings may have solved the issue.

You will need an edid minder to force your chromecast to output a compatible resolution. Some DACs have edid minders built in e.g. https://www.extron.com/product/dvirgb200 <-this particular device is no good for you because you’ll need to extract audio from chromecast

[ganglyman]

Thanks! The Tendak is a non-power-required one. (It's the Tendak Active 1080P Female HDMI to VGA Male Converter on Amazon). Do you think I need a powered one? And I suspect both the GC video and Chromecast (set to 480p) are outputting 720x480. So do you think I need an edidminder for both (even if I have 'em going thru the OSSC)? Thanks!

[strayan]

Yes, you definitely need an externally powered one because gcvideo can’t supply the power the tendak needs.

How are you setting the chromecast to output 480p?

Gcvideo outputs 480p by default so there is no need for a edid minder unlike the chromecast

[ganglyman]

The Tendak needs power? It says it's a plug-and-play converter, no external power required. I have it plugged into the PC RGB in the back of the tv and the GCvideo hdmi plugged into the Tendak. How does the Tendak normally receive power if there's no power adapter or power input for it?

I hooked up the Chromecast to another tv and manually set it to output in 480p.

Thanks for all the help! You know so much more than me haha.

[strayan]

Yes, ordinarily a HDMI device would supply power on pin 18 which then tendak would use. The gcvideo can’t supply this.

I hooked up the Chromecast to another tv and manually set it to output in 480p.

With what user interface?

[ganglyman]

Sweet, glad I know that now!

I selected it in the display settings menu on the chromecast. There's also a spot for color format. YCbCr 4:4:4 8-bit was previously selected. The other option is RGB 8-bit. Which of those should I select for the Hitachi?

[strayan]

I selected it in the display settings menu on the chromecast. There's also a spot for color format. YCbCr 4:4:4 8-bit was previously selected. The other option is RGB 8-bit. Which of those should I select for the Hitachi?

Answer hinges on which DAC you buy.

You don’t need an EDID minder if you can manually set your chromecast to output 480p.

[ganglyman]

I just bought the FOINNEX Active Male VGA in Female HDMI from Amazon. It was on RetroRGB's Amazon page for Converters. Do you think that one will work alright?

[strayan]

That looks like a VGA to HDMI adapter (a device which digitises an analog signal).

You need a device which converts a digital signal to an analog signal (Digital to Analog Converter aka DAC).

You need one that can be externally powered.

[ganglyman]

Thank you! I just ordered the PORTTA HDMI to VGA Converter box instead. Which color format should I use for that DAC?

[strayan]

Thank you! I just ordered the PORTTA HDMI to VGA Converter box instead. Which color format should I use for that DAC?

GCvideo allows you to toggle between RGB and ycbcr modes so just cycle through them until the picture looks right.

[ganglyman]

Thanks! Is RGB or YCbCr essentially RGB full or RGB limited?