32x dark on HDTV

[blackevilweredragon]

I have a 27" CRT HDTV, and it's bright and everything, but if I play a 32X game, the brightness is WAY too dark, I have to boost the brightness just for the 32X..

Is there a way to fix this?  If I play a Genesis game with the 32X attached though, it's fine..

EDIT:  Just to mention, when I hook the 32X up to my regular SDTVs, ALL of them, the picture is bright..

[ido8bit]

How are you connecting the 32X?  Are any other systems too dark?

[blackevilweredragon]

How are you connecting the 32X?  Are any other systems too dark?

The 32x is connected via a stereo Composite cable.

Only the 32x is dark.  My SNES, PS1, Dreamcast, N64, and Xbox when connected to this TVs composite, is perfectly bright..  (for the record, my PS1, Dreamcast, and N64 are usually connected S-Video, and the Xbox HDTV Component)...

The 32x when playing a Genesis game is bright, but pop in a 32x game, and white becomes grey, and I have to push "Picture" on my TV remote, which boosts the brightness.  THEN white becomes white, but black becomes dark grey...

[ido8bit]

Have you tried turning off any and all automatic processing on the TV (what those options are called varies from TV to TV)?  The TV may be trying to "correct" something that doesn't need to be corrected.  

[blackevilweredragon]

Have you tried turning off any and all automatic processing on the TV (what those options are called varies from TV to TV)?  The TV may be trying to "correct" something that doesn't need to be corrected.

this TV doesn't have an auto picture mode, it's just a straight capture into it's built-in scaler, which is required, as this TV can only show a 1080i or a 540p picture..

[blackevilweredragon]

I called up the TV company today, and apparently this is an issue they have encountered before.  

They told me that when the 32x is actually running a 32x game, it's overlay circuit kicks in, and this causes problems with the TVs internal scaler, as overlaying on it causes the picture to darken..  they told me that getting an RGB to Component adapter with some caps on the RGB lines may help..

too bad that's the expensive route, for such an old game console..

[ido8bit]

Honestly at this point it's probably MUCH easier to simply play 32X on one of your other TVs.

It may be possible to add an RGB input to the TV, but it won't be easy.  Something that isn't really worth considering unless you'll also use that RGB input for other consoles.  The starting point would be to find the signal processing IC in the TV and find a datasheet for it.

[blackevilweredragon]

Honestly at this point it's probably MUCH easier to simply play 32X on one of your other TVs.

It may be possible to add an RGB input to the TV, but it won't be easy.  Something that isn't really worth considering unless you'll also use that RGB input for other consoles.  The starting point would be to find the signal processing IC in the TV and find a datasheet for it.

Well, for RGB, the TV manufacturer states that my model supports Sync-on-Green via the Component ports, it's an undocumented thing as theres many different revisions of my TV..

How do I wire this up?

[ido8bit]

Well that makes things easier.  More TVs with component inputs should have this feature, after all it needs to be converted to RGB for the CRT anyway.

You'll need to build a circuit to combine the composite sync with the green video signal.  Then it's simply green+sync to green, red to red, blue to blue.  The Genesis 2/32X video pinout is available on the gamesx site.  

A circuit that converts RGB HV sync to RGB sync on green is available here: http://www.smoke.com.au/~ic/fix-freq.html

As the Genesis/32X already outputs composite sync you won't need the first stage of the circuit, so you can ignore the 1st 3 gates.  Connect the composite sync to the input of last gate (pin 10 if you are following the diagram).  There are probably simpler circuits out there to combine sync onto green, this was just the 1st one I found.

The last time I needed to do something similar I found a different circuit that someone built to connect an old Mac to an Apollo workstation sync on green monitor.  I can't find that page now, but it would be better as old Macs do output composite sync.  
 

[blackevilweredragon]

Well that makes things easier.  More TVs with component inputs should have this feature, after all it needs to be converted to RGB for the CRT anyway.

You'll need to build a circuit to combine the composite sync with the green video signal.  Then it's simply green+sync to green, red to red, blue to blue.  The Genesis 2/32X video pinout is available on the gamesx site.  

A circuit that converts RGB HV sync to RGB sync on green is available here: http://www.smoke.com.au/~ic/fix-freq.html

As the Genesis/32X already outputs composite sync you won't need the first stage of the circuit, so you can ignore the 1st 3 gates.  Connect the composite sync to the input of last gate (pin 10 if you are following the diagram).  There are probably simpler circuits out there to combine sync onto green, this was just the 1st one I found.

The last time I needed to do something similar I found a different circuit that someone built to connect an old Mac to an Apollo workstation sync on green monitor.  I can't find that page now, but it would be better as old Macs do output composite sync.

Ok, i'll give that a shot later in the day...

Only thing that stinks though, being the sync-on-green on my HDTV is undocumented, is it involves a little hack...

My HDTV has 2 component inputs, both support up to 1080p (gets converted to 1080i as the tube can't do it), and as low as 240p (will get scaled to 540p, manufacturer says)..

Both inputs can have individual settings, but are normally global between the two..  In the "service menu", there's a mode under each component inputs settings, it says "Format", and it has two options, "Difference", and "S-O-G" (sync on green)..  those are not global settings, but are individual settings..  luckily this means i can have my Xbox and cable box hooked up to one component input, and the other input for the 32x, being RGB...

hopefully it works ok..  will post when im done...

[blackevilweredragon]

Ok, built the circuit, told TV to be in Sync on Green, and when the 32x is still on, it's STILL too dark..  But as soon as I put in a Genesis game, it's bright again...

[ido8bit]

I really don't know where to go from here.  Obviously there's something about 32X video that your set doesn't like, but without knowing exactly what it doesn't like I can't say where to go from here.  

Going back to what the manufacturer said maybe putting caps on the RGB lines will help.  

At least you now know you can feed your TV RGB, so you can hook up your other consoles via RGB.  

[blackevilweredragon]

I really don't know where to go from here.  Obviously there's something about 32X video that your set doesn't like, but without knowing exactly what it doesn't like I can't say where to go from here.  

Going back to what the manufacturer said maybe putting caps on the RGB lines will help.  

At least you now know you can feed your TV RGB, so you can hook up your other consoles via RGB.

i was going to try caps, but they never said what kind of caps....

[ido8bit]

Electrolytic capacitors are usually used, 100uf or 220uf, 10V or 16V (you could use lower voltage caps, but 10V or 16V is usually the lowest voltage most places carry).  The capacitors go in series with the RGB line between the system and the monitor.  In your case connect the positive side of the capacitor to the output from the 32x, the negative side to the TV input.  In the case of the green signal I'd place the capacitor before the sync combiner circuit.  

Hopefully these will solve your problem.  Other posts here and elsewhere suggest that people have needed capacitors to solve dark picture problems with various combinations of monitor and system.  

[blackevilweredragon]

ok, i found a few 10v caps lying around, and put them in, as you said how to, and now the 32x is nice and bright..

however (this is starting to be a headache), when I play a Genesis game, it's too bright, where light grey becomes white..  matter of fact, just a couple minutes in a genesis game, and the TV blue's the screen with the message "Peak Warning!"

[Endymion]

Make a switch.

[blackevilweredragon]

Make a switch.

that's what im thinking about doing..  I have a stereo composite switch, which I am sure will work just fine, ill use yellow for green, red for red, and white for blue...

[ido8bit]

I'd just stick 3 pole switch in the RGB lines.  It would be easy enough to mount in/on whatever you've built the sync combiner circuit into.  Wire it so in the closed position it shorts the caps out.  That would be the easiest/cleanest way I can think off to bypass the caps when playing genesis games.  

Another option maybe to try using lower value caps.  If you're currently using 220uf try 100uf, 100uf try 47uf.  You maybe able to find a happy medium where the 32x is bright enough without making the Genesis too bright.  

If it were me I'd install the switch.  If you want to go to extra effort it's probaby possible to set something up the switches automatically when the the 32X is active (use a 4066 or similar, tie it to a line that goes high only when the the 32x is in use).  

I just run a  seperate Genesis dedicated to 32X games.  Though in my case it's because the 32X isn't compatible with some of my other gear (Action Replay, Magic Drive).  It's easier to use a 2nd console for 32X games rather that stuff around unplugging cables all the time.

[blackevilweredragon]

Ok, since using the RGB cable, I still had a feeling that it was dark, even with caps on the line..

Recently, I found Knuckles Chaotix at the flea market, so for two reasons, I got the game:  I like the game, AND it has a good color test screen..

Then, I saw this..  Notice my 32X don't even go side by side with the Genesis, and not only that, their last shades of grey, don't even show up..  (you can't see it, but on the Genesis side, the last grey IS there, but barely that the camera didn't see it)..

And that's RGB with caps...

[ido8bit]

Interesting...  I have Knuckles Chaotix somewhere so I'll try this someday (if I remember, my 32x stuff is in storage at the moment).