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Can't Get Vga To Work


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#31 AnnaOlum

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Posted 31 January 2012 - 01:29 AM

All right, learned something new again. Thanks! biggrin.gif

Edit: Just tested the other CRT Monitor - it doesn't work. I only get garbled output.

Edited by AnnaOlum, 31 January 2012 - 01:33 AM.


#32 xboxmods2977

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Posted 31 January 2012 - 04:36 AM

Yea, I'm thinking that your LM chip is still not working for some reason, but at least you ended up having a S.o.G monitor. Have fun! smile.gif

#33 AnnaOlum

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Posted 31 January 2012 - 03:20 PM

My HDTV doesn't work too. I need output on it.

My LM1881 Chip doesn't work? Is there a way to test it? Perhaps with a multimeter?

Edited by AnnaOlum, 31 January 2012 - 03:26 PM.


#34 Heimdall

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Posted 31 January 2012 - 05:15 PM

You need to provide more details. Are you saying you have two monitors and an HDTV with a VGA input? If so, have you looked at the manuals for all three to see what VGA modes they support?

At a guess I'd suspect that one of your monitors supports SOG, while the other monitor and the HDTV don't, and that xboxmods2977 is correct and your LM1881 chip is broken, but looking at the manuals might help confirm this.

Also, you might need to switch your Xbox into NTSC mode to get the higher VGA resolutions to work. I've never tried VGA on a PAL Xbox, but given the brain-dead implementation that Microsoft chose I'd be surprised if VGA gave you any reasonable resolutions unless you are in NTSC mode.

Finally, post some photos of your work - we might be able to spot if there's a wiring problem.

#35 AnnaOlum

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Posted 31 January 2012 - 06:13 PM

I'm already in NTSC mode - I switched the box to it via Enigmah's PAL/NTSC switcher.

Regarding the wiring: Maybe I will desolder it and start from scratch.

#36 AnnaOlum

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Posted 31 January 2012 - 07:46 PM

By the way - my HDTV is a LG 42PC51...

#37 AnnaOlum

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Posted 31 January 2012 - 10:40 PM

Another thing: Where can I find the Pixel8 VGA BIOS? No luck on the usual places...

#38 xboxmods2977

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Posted 01 February 2012 - 02:49 AM

QUOTE(AnnaOlum @ Jan 31 2012, 07:46 PM) View Post

By the way - my HDTV is a LG 42PC51...
According to the service manual, your TV does not support Composite Sync, A.K.A. Sync on Green.
If you would like to connect your Xbox to this TV, you will have to either correct your LM1881 circuit (and pray that your TV accepts the signal), or connect to it via Xbox Component cables. Your YPbPr connections are on the back of the TV.

QUOTE(AnnaOlum @ Jan 31 2012, 10:40 PM) View Post

Another thing: Where can I find the Pixel8 VGA BIOS? No luck on the usual places...
A bios change won't help you. Your issues are hardware related.

Edited by xboxmods2977, 01 February 2012 - 02:52 AM.


#39 AnnaOlum

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Posted 01 February 2012 - 03:07 PM

QUOTE(xboxmods2977 @ Feb 1 2012, 02:49 AM) View Post

A bios change won't help you. Your issues are hardware related.


Yep, realized that now. Plugged out the LM1881 from its socket and it's still working on the first monitor.

#40 AnnaOlum

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Posted 03 February 2012 - 05:43 PM

Dang it! Switched the old LM1881 with a new one and it's still only working on the first monitor. Could it be the wiring?

#41 xboxmods2977

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Posted 03 February 2012 - 06:57 PM

Probably. Be sure to check your chip's orientation. Pin 1 is marked with a dot.

Edited by xboxmods2977, 03 February 2012 - 07:02 PM.


#42 AnnaOlum

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Posted 03 February 2012 - 07:06 PM

I checked that first. Like I said: Maybe I'll do the whole wiring from scratch to eliminate all problems biggrin.gif

#43 AnnaOlum

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Posted 18 February 2012 - 06:30 PM

Yeah!!! Rewired it and now it works almost correctly. The only downside is that when i hook it up to my HDTV the picture constantly flickers and jumps on the screen. On another HDTV it works fine (but only 480p).
Is there a way to fix it?

#44 xboxmods2977

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Posted 18 February 2012 - 07:32 PM

Probably not. You've gotten it to work properly on an HDTV (unfortunately, not yours), which means everything is set up correctly now. The issue is that the VGA signal that the LM1881 method produces is not spec identical to a true VGA signal. For this reason, some LCD TV's with VGA input simply do not like it. The only other alternative that may work better is the xbox internal VGA mod, explained here.

Side note: Do be aware that some HD TV's, using the VGA input, cannot display 1080i resolutions properly. You can try switching that resolution off and just leave the 480p, and 720p resolutions on and see if that makes any difference.

Edited by xboxmods2977, 18 February 2012 - 07:35 PM.


#45 AnnaOlum

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Posted 19 February 2012 - 02:33 AM

Dumb question: Could it be possible that it's not working correctly because I have grounded the pins 11 + 12 & 13 + 14 and have no VGA bios installed?

Edited by AnnaOlum, 19 February 2012 - 02:54 AM.





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