Home Theater Forum and Systems banner

Newbie need HDTV expert help with RGBHV

2K views 4 replies 3 participants last post by  KalaniP 
#1 ·
Hello Mitsubishi forum! I've got a problem that is so foreign to me, I'm not even sure I'm asking the right questions.

Just got my first high def TV, a Mitsubishi WS-55819. A bit behind the times, perhaps. We've been watching our favorite shows on computer monitors for years and figured, hell, why not get a GIANT one? So I picked up this TV from a buddy for $100 and started cramming my head full of as much HDTV stuff as I could. Have figured out the convergence and sorta got my head around the "Red Push" fix and all that. One of the main reasons we bought this moo humungous TV is that it had VGA input. The only video device I have is an older laptop (Toshiba Satellite A135-S4727) and our Yamaha receiver with Component input/output.

As the Mitsu experts here know, that didn't exactly work out as I had planned. VGA input on this unit is locked to 640x480. I then found out that to convert VGA to component it takes a $200 box. So, we just hooked up the SVideo and spent a week enjoying a regular TV. Well, as you can imagine, SVideo on this thing isn't really great. I stumbled across some information about RGBHV and VGA and figured, hey! I'm one cable away from seeing this thing in 1080i, so out came the soldering gun! As my presence here would suggest, that didn't exactly work out either.

At first, it flat out didn't work. I figured I had messed the cable up somehow and that was that. Just so happened to try rebooting the computer. To my surprise, the BIOS/POST screen showed up, the TV said 480p, and it seemed like I was in business! As soon as Windows 7 started loading and the resolution changed, it immediately stopped working.

I've tried every resolution and refresh rate available, have tried installing new "monitor" drivers, including the Microsoft provided "Generic TV" one and a "Generic Flatscreen 1920x1080x60" and again went through all the resolutions and refresh rates.

The TV has an error across the bottom of the screen telling me that the input signal may be invalid. After fiddling with the resolution some more, it will eventually say that there is no signal at all, and it will turn the TV off after two minutes.

I'm at a complete loss. The manual says that it supports 1080i if I've got RGB and separate HV sync. I very carefully made the cable and connected H+ and V+ to the tips of RCA/Phono cables, and the H- and V- to the barrels using the schematic found on Wikipedia here: (link removed, I don't have five posts yet. Wiki article: VGA_Connector)

I remember reading something about sync polarity being different, but don't remember what exactly they were talking about. I have no experience at all with high def TVs outside of the last 16 hours or so and I'm /highly/ confused. I figure if it's working at 480p, then the polarity is correct, maybe?

Is it a matter of simply finding the right resolution and refresh rate on the computer? Do I need to flip around the polarity on the sync cables? Is what I'm trying to do even possible?

Thanks for taking the time to read this long rambling post. My apologies for my ignorance, I hope I'm just making some noob mistakes.
 
See less See more
#3 ·
According to intel's website, this on board graphics on the laptop supports interlaced output.

Found at: on the intel website, gma950
(sorry, im still under five posts and can not post links)

Assuming I can figure out how to turn that on, do you know which resolution I should be outputting at? Any other tips that might help me along?
 
#5 ·
You're trying to put a computer picture onto a rear projection CRT-based HDTV? I've done it, but it's not fun.

It's a long game of trial and error, trying to find the precise combination you need. There are issues with overscan, refresh, front porch, back porch, you name it, in addition to pure resolution.

There is shareware called "Power Strip" out there that lets you control every last detail of output, I'd look into that.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top