PhilC's H4 Mongrel edition build x 3

[exxos]

@PhilC Great job! is that changing the resistors ?

[PhilC]

@exxos , nah it was by resetting the monitor, I'd been messing with it when trying your VGA adaptor.

I'll try the resistors later if I get a chance.

[exxos]

@exxos , nah it was by resetting the monitor, I'd been messing with it when trying your VGA adaptor.

I'll try the resistors later if I get a chance.

That maybe tricky as we don't know if the H4 or adapter is upping the brightness, or both!

[PhilC]

I'm using the built in VGA at the mo, I'd just not used the monitor since messing with the adaptor. So it's the onboard VGA that's too bright.

[Icky]

@PhilC - I get the same, extremely washed out when using one of my monitors and then just very bright on my other like @PaulJ gets.

If I plug in an original STFM into both the monitors the image is the same colour and brightness. I still haven't got round to swapping the 75R to 100R. Things keep getting in the way.

[PhilC]

@PhilC - I get the same, extremely washed out when using one of my monitors and then just very bright on my other like @PaulJ gets.

If I plug in an original STFM into both the monitors the image is the same colour and brightness. I still haven't got round to swapping the 75R to 100R. Things keep getting in the way.

Yep, I know all about the lack of time and other things getting in the way. otherwise I'd have finished much quicker. At least V2 board will be much quicker.

[Smonson]

I've got a question about the RGB driver... I don't see any circuitry to pull the outputs down during the blanking interval. They need to go down to 0 level or preferably just under, in order to set the black point. The effect of that, if it's not working, is a too-light image especially when the ST background colour is white. Could I suggest setting colour 0 to black and see if that has any effect?

[exxos]

Blanking is wired. There was a huge topic about it all https://www.exxosforum.co.uk/forum/viewt ... =77&t=1235

When blanking wasn't working the image ended up mostly black and would only show a proper image with a black border colour.

As I said, first try 100R resistors, then also try putting 100uf in series with the same resistors as they may be a DC offset causing the problem. Originally we had the caps, but we left them out as they made no difference, but maybe they need to be there with some monitors, we don't know yet.

[PhilC]

And on to board no.2 now.

This one is going to be a little different. So far its SMT Glue and MMU.

I've left the caps and resistors from the rgb circuit until I've had a chance to determine the best values with my first board.

I've got a few small potentiometers that I'm going to try and shoehorn onto the rgb circuit of my working board, will post the results hopefully tomorrow.

Anyway, here's the progress so far

20191210_214958.jpg (445.47 KiB) Viewed 3593 times

[Smonson]

Blanking is wired. There was a huge topic about it all https://www.exxosforum.co.uk/forum/viewt ... =77&t=1235

Oh yeah! At my age the memory comes and goes...