CurtPalme.com Home Theater Forum

[mp20748]

10 days so far, and I've still not got my test bed working. So do anyone local have a Marquee chassis they're not using.

I've mentioned this before. My test bed (8500LC) failed from a glycol leak from the RED CRT. it had been stored in my shop for about a year. And I then put it back on the cart. It worked well for about a month and then the HVPS failed. And before that I noticed a few problem controlling some of the things in the menus.

Right after the HVPS failed, I noticed the glycol leak. Cleaned the glycol replaced the HVPS but still nothing. Then removed the replaced the mother board, still not working. The following week I replaced the back plane board - nothing.

The only thing i can come up with is the glycol must have leaked behind the connector for the HVPS, and damaged the connection there.

I've tried everything, but doing a further disassemble to look at that connector.

So if anyone local has a spare mother board they no longer need let me know.


I'll really need it to go after the line problem.

[barclay66]

Hi,

there are two motherboards: The upper one and the backplane. Which is it You need and which Version should it have?

Regards,
barclay66

[mp20748]

[barclay66]

OK,

So Your upper Mother Board is an older version (large connectors to the VDM/CVA boards plus jumper wires for the additional Ultra Geometry signals).
I have at least two working spares as I have at least three backplane boards that would fit there. I send You my board inventory list via PM...

Regards,
barclay66

[mp20748]

Thanks for the list. I have an Ultra mother board, and have not yet decided to put it in my test unit.


Also, I found a way to get pattern button to work and display the internal pattern and still keep the jumper on pins 11 and 14 of the SD5401 chip. And so far I can bring up the convergence grid and internal patterns, but of course I'm not able to bring up the imposed menus. That's where the fast switching is involved and why a relay cannot be used there.

So far, I've added a to92 transistor and two resistors, and I'm not through..

[barclay66]

[mp20748]

Presently on my 02 VIM that's operational as I type, I'm able to bypass the video (external) section of the SD5401 switching chip, which allows me to keep the exact same higher bandwidth and cleaner image the same that I had achieved with the jumper, BUT, I'm also getting full menu's and OSD.


And I'm doing it all WITHOUT the mini board..





I did it!


.

[stridsvognen]

Thats realy nice.. Now we just need thet to be standard on all Marquee machines around..

[Zolzar]

Oh man....I may have to take the Marquee out of storage. I love reading this stuff! Amazing!


John

[stridsvognen]

We need to be quiet about this.. Emagine if all those that have SONY and Barco machines also want to resolve 1080P 72 hz..

The Marquee prices will go crazy

[Nashou66]

I added the jumper last night on a completely stock board and did not notice that much of a change on screen or on my scope. But It is an unmoded 02 vim and I am sure to notice any changes you'd need a vim like Mikes.

Good work Mike on the menus, did you add switch to add the menus before the RGB op amp or into the Decoder section since that is the same source as the RGBHV?

Nashou

[mp20748]

[Nashou66]

Sounds good Mike. I also have one of my Longbows with a memory for 1080p@72 from My TV-One and can add 1080p96 to see how it handles it. I know my VNB's are stock but it be fun anyhow.

Nashou

[jbmeyer13]

[Nashou66]

Mike I am looking at the schematics and the SD5401 Chip digram and am trying to
figure out what is going on with the video path and internal video. here is the chip.
Now I jumped 11 to 14, well to the solder point inform of the AD835 which connects
to pin 14 from under The SD5401. I tested continuity to make sure.
But in the digram below 11 and 14 never make contact. And if you look at the schematic
there is another part pins,8,9 and 10 that don't make sense internally . I remember
Jorge explained how the system worked but can not find it. I think he said that the video
and internal video are both switched on and off so fast that we see both while the internal
video is selected and the VSEL and VSEL* are active. Now the Service Manual theory of
operation states that these are also active during the blanking section IIRC. So is the video
as it passes through the chip and to other parts of the chip constantly being turned on
and off even when the internal video is not selected? just trying to follow the video path
and its not making sense.






Athanasios

[mp20748]

On the diagram, you may be looking at the dual inline diagram of the chip, which is 16 pin, instead of the SOIC 14 pin one on the VIM.


That chip circuitry serves quite a few functions, with blanking being one of them. And that is also how they put the black background on the OSD. Both are happening on pin 12 (V SEL) to include switching the video signal.

[Nashou66]

DOH!!!! How did I mis that!!!???!!!

Thanks Mike it all makes sense now as it did way back when that we first talked about this.

Mike I found a 300mhz chip has under 5ns switching times. That might be the ticket. I forgot what the BW of the SD5401 is.

Nashou

[Nashou66]

Ok found the internals of the SD5401



Here is the single channel version of the SD5401

http://www.linearsystems.com/assets/media/file/datasheets/SD213.pdf

Athanasios

[stridsvognen]

What i experienced is that the VIM will not change much with standard neck boards, its not before all the video chain have the high bandwidth i started to see some real visible differences.

And if i understand right, the latest mods bypasing the chip only performs visible better on the super high bandwidth neck boards ??

Mike.. Correct me if im wrong..?

[mp20748]