RGB NES / Famicom and jailbar removal

I didnt realize the regulator was so hot until i accidentally touched the heatsink and it burned me a bit.

yeah, if all else fails - grab another nes.

its not like i only have 1.

i wanted to see exactly how bad the 11 would be if i wired it back up using what ive learned since i first wired it.

just for good measure, once i build that voltage divider (i dont have the resistors) and it stops rolling (hopefully)

it seems like the only electronics parts place locally is radio shack and they never have shit i need, but ill look for the resistors tomorrow.

Im going to sheild the ppu/cpu.

My 05-03 ppu will be built on an 07 nes revision. I already have it and all the parts to build the address line circuit, +1881 +amp.

btw, whats that jumper for on bakus new circuit? thats the only thing i didnt quite understand.

is that just to switch between an rc2c03 and and rc2c05?

mvsfan wrote:

I didnt realize the regulator was so hot until i accidentally touched the heatsink and it burned me a bit.

The toaster nes heatsink is really small, and sorry to burst your bubble but it's supposed to get really hot, it's a heatsink.

The jumper I believe is to switch between the 05 / 03 series ppus and the regular rp2c03b.

I know its supposed to get hot, but now its about 2/3 as hot as it was.

im gonna play with this voltage divider if i can find the resistors today.

mvsfan wrote:

I know its supposed to get hot, but now its about 2/3 as hot as it was.

Really? That's odd.

voltage divider didnt work. Nothing melted down, but it turns my screen into what it looks like with no lm1881 hooked up.

i just got some interesting results with the sync.

I built a voltage divider with 1 200 ohm resistor to ground, and a 1k pot on the positive input leg of the voltage divider.

If i add resistance, the picture will roll faster until it goes out to diagonal black lines.

if i take away resistance down to zero, the picture slowly rolls like its been doing.

I now believe that my component encoder, is looking for 5v on sync, not 4.5 that im getting.

so how would i Increase it from 4.5 to 5?

Ive got another lm1881 on order and im going to try that next.

thanks for suggesting that voltage divider, drakon. I believe i now know whats wrong with the sync. not enough voltage OUT. Bad 1881???

You didn't mention you're using a component encoder. I have one rgb to component video adapter that won't work with composite sync but it works with composite video like regular rgb tvs. I'm sure I could hack the encoder to feed it straight sync I just never bothered looking at the pcb. Unfortunately with a rgb nes you'd need to wire up a video encoder to get composite video.

Drakon wrote:

You didn't mention you're using a component encoder. I have one rgb to component video adapter that won't work with composite sync but it works with composite video like regular rgb tvs. I'm sure I could hack the encoder to feed it straight sync I just never bothered looking at the pcb. Unfortunately with a rgb nes you'd need to wire up a video encoder to get composite video.

thats not it either. Im using raw c-sync on my snes and genesis. They both work fine with this encoder. I really think its a voltage issue since i played around with that adjustable voltage divider.

mvsfan wrote:

Drakon wrote:

You didn't mention you're using a component encoder. I have one rgb to component video adapter that won't work with composite sync but it works with composite video like regular rgb tvs. I'm sure I could hack the encoder to feed it straight sync I just never bothered looking at the pcb. Unfortunately with a rgb nes you'd need to wire up a video encoder to get composite video.

thats not it either. Im using raw c-sync on my snes and genesis. They both work fine with this encoder. I really think its a voltage issue since i played around with that adjustable voltage divider.

the lower the voltage, the worse the picture gets until it just goes out.

mvsfan wrote:

mvsfan wrote:

Drakon wrote:

You didn't mention you're using a component encoder. I have one rgb to component video adapter that won't work with composite sync but it works with composite video like regular rgb tvs. I'm sure I could hack the encoder to feed it straight sync I just never bothered looking at the pcb. Unfortunately with a rgb nes you'd need to wire up a video encoder to get composite video.

thats not it either. Im using raw c-sync on my snes and genesis. They both work fine with this encoder. I really think its a voltage issue since i played around with that adjustable voltage divider.

the lower the voltage, the worse the picture gets until it just goes out.

i think im going to measure the voltage on sync on my snes and see what its putting out.

i cant wait until the new lm1881 gets here, so i can eliminate it as the problem.

to eliminate the ppu as a possible source of this problem i swapped it with an rc2c04 and it rolls too.

on a side note - ive read that mike tysons punch out doesnt work right on an rgb ppu and i was trying to play it yesterday and sure enough the graphics are corrupted.

do you have any problems with this game?

well, i didnt get my 1881 in today so i guess this project is on hold until i do.

the new 1881 didnt change a thing. also tried adjusting the pots in my component converter that didnt do anything either.

looks like i just might have to find a way to boost the voltage on sync.

what else could be going on with it? i cant think of a damn thing i havent checked or changed.

Run sync into where the nes composite video is fed from the regular and tap it at the video out rca jack. That will amp it.

im doing that.