Topic: Can't Get Vga To Work (Read 806 times)

xboxmods2977 · « **Reply #45 on:** February 22, 2012, 03:05:00 PM »

Frosty's uses mode 2+3, so keep that in mind when troubleshooting. Check resolution settings on the xbox, maybe try using your CRT monitor to do so.

AnnaOlum · « **Reply #46 on:** February 22, 2012, 04:02:00 PM »

Already checked that and also the wiring and chip. Everything is in order.
But it's still not working.

AnnaOlum · « **Reply #47 on:** February 24, 2012, 02:35:00 PM »

Could it be that the LM1881 is incompatible with the X2 5035 and my HDTV?
When the box was softmodded with ndure 3.1 it worked but now with the TSOP flash it doesn't work anymore.

Should I try it with the internal sync mod? What material do I need (except 2x 74HC14) and what does the circuit look like?

EDIT: Just found some infos about the LM1881 which said that I could get real HSYNC out of the chip with a NAND and AND Gate. How does this work?

xboxmods2977 · « **Reply #48 on:** February 26, 2012, 02:09:00 PM »

QUOTE(AnnaOlum @ Feb 24 2012, 10:35 PM)

Could it be that the LM1881 is incompatible with the X2 5035 and my HDTV?

That depends. Does it still work with your VGA (PC) monitor after the VGA bios was flashed to the TSOP?

xboxmods2977 · « **Reply #49 on:** February 27, 2012, 12:40:00 PM »

QUOTE(AnnaOlum @ Feb 27 2012, 03:46 PM)

Yep, it still works on all PC CRTs and PC TFTs/LCDs/LEDs we have in the house.

Then I would have to say yes, even tho I don't know why at the moment. LOL

AnnaOlum · « **Reply #50 on:** March 22, 2012, 10:43:00 AM »

I recently ordered two samples of the EL1883ISZ from Intersil. This chip has real HSYNC.
Can I use it for VGA Output and how do I do it?

xboxmods2977 · « **Reply #51 on:** March 23, 2012, 11:07:00 AM »

QUOTE(AnnaOlum @ Mar 22 2012, 05:43 PM)

I recently ordered two samples of the EL1883ISZ from Intersil. This chip has real HSYNC.
Can I use it for VGA Output and how do I do it?

Looks to me that this chip has the same pinout as the LM1881n. So, you would use/wire it just the same.

xboxmods2977 · « **Reply #52 on:** March 29, 2012, 08:48:00 PM »

QUOTE(xboxmods2977 @ Mar 23 2012, 06:07 PM)

Looks to me that this chip has the same pinout as the LM1881n. So, you would use/wire it just the same.

Scratch this.

H-Sync is output on pin 7 of this chip, so you would de-solder the line to pin 1 on your 8-pin socket and solder it to pin 7.
Found another one too like this. The GS4981 is also a video sync separator with true H-sync output, but with these chips, it looks like you may need to invert the H-Sync line. Not positive about that tho. Worth a shot.

I just realized that one of the issues with the LM1881 is that it outputs a composite sync signal into the VGA monitors H-Sync line, which some monitors (and HDTVs) will not like. This is one of the reasons why the LM1881 isn't 100% compatible with all VGA monitors. I cannot believe I never noticed this before.

Also a side note, the EL4581 does not have H-Sync out. It is the same as the LM1881, according to the datasheet.

Author Topic: Can't Get Vga To Work (Read 806 times)