Not All Hip Gear Screens Created Equal?

[A.J. Franzman]

I just got my Hip Gear Screen Pad screen hooked up to my 2600, tried a few different things (at first I had a diagonally scrambled picture, but a slight tweak of the VCO trimpot near the amber ribbon cable fixed that) and got it working. Picture is beautiful, though tiny. Better resolution than my Casio TV-880; I can actually read the Activision logos now! I haven't tried to find the Adventure dot yet...

But when I tried to power it from my regulated +5V, it doesn't work. My screen is a PS2 version from Canada (eBay seller "ponybids"), which normally runs from ~ 12V. Ladyada listed power usage for Hip Gear screens all the way down to 5 volts here: Hip Gear Screen Pad pinouts & power req's
When I try mine at 5V, it blinks and goes off. If I connect the TV-880 to the A/V connections in parallel (but using separate power), I can see that sometimes the game will start and be working while the Hip screen blinks and goes out, other times the game will glitch or not come on at all, but the Hip Gear screen never stays on at 5V. It will work at 6V but doesn't really like it; it gets a moire' pattern of wavy lines slowly scrolling down at 6V.

Is there a trick to making these screens run on 5V, or do some of them just not handle it? Does anyone else have this problem?

BTW, my 5V regulator is a switched-mode supply that's 93% efficient and zero dropout capable down to 4.5 volts input. I expect to get 3-4 hours of runtime from 6 NiMH AA cells, and that's without LED-modding the screen.

[G-force]

This is probably a dumb question, but did you bypass the 7808 on the adjust board?

I remember several other people in another thread said they had the same problem. They got the screens to run off 7.2v but not 6V.
It seems most of the non-6V screens were being sold from canada. Boycot canada screens!

This is weird cause I ordered one off ebay a few weeks ago for my NES p0cket and it works fine....

[A.J. Franzman]

This is probably a dumb question, but did you bypass the 7808 on the adjust board?

Yes I did, but forgot to mention it. Thanks for asking.

I even tried it with the 7808 removed but not bypassed (therefore no power to the audio amp at all), didn't make any difference.

[gannon]

well, I know there are a few board revisions for the screen. My old one had a main board that was just about the same size as the lcd, but my new one has a main board that's way bigger than the lcd
Here's the input schematic of my older screen though:

[A.J. Franzman]

I didn't realize there were differences in the screen part at all, as the question had been asked before and the response was something like, "it doesn't matter which one you get".

The one I have is the version with a large video mainboard.

[Triton]

mebe those are the ones that suck?

[A.J. Franzman]

Here's the input schematic of my older screen though:

Thanks, but I never see any of your images. When I try to go directly to gannon.tk, I get "Cannot find server" error. Is that machine always on?

[gannon]

There's an access problem for certain IPs for some reason, whenever I've contacted the server they say they'll work on it and do nothing about it I'll put it on imageshack real quick.

[A.J. Franzman]

There's an access problem for certain IPs for some reason, whenever I've contacted the server they say they'll work on it and do nothing about it I'll put it on imageshack real quick.

Thanks, got the schematic now.