can you convert quadra 650 board to quadra 800?

[imactheknife]

title says it all...just curious

 

[Unknown_K]

http://www.cy384.com/projects/centr...ra 800,MHz, peripherals stop working properly.

 

[MrFahrenheit]

I believe if it's a Q650 at 33mhz, you can easily make it Quadra 800 board.

 

[lobust]

Yes*, all you have to do is plug the led from a Q800 into the header that's in the corner of the board above the battery holder.
It's a three pin header (IIRC) and two of them are jumpered on the plug for the LED.

The boards are identical*, the rom/system software changes the gestalt value depending on whether those two pins are jumpered or not.

Edit:
* if the 650 is a Quadra and not a Centris.

 

[imactheknife]

oh, so a Centris 650 25mhz full 68040 is different than a quadra?

 

[lobust]

oh, so a Centris 650 25mhz full 68040 is different than a quadra?

I think the differences are trivial and easily "corrected". If you read the article that Unknown linked above they are detailed.

There is another much older resource somewhere on the internet that details the differences too, but I forget where...

Edit:

Here: http://www.applefool.com/clockchipping/wombat.html

 

[imactheknife]

Yeah saw these sights. Just wanted to see if anyone had converted one before. My Q800 board just wont post past chime. No video, no scsi, nothing.. so sad to have to replace it.

 

[Unknown_K]

Hmm Q800 boards came with tantalum capacitors so you didn't have to worry about leaking caps ruining boards like in the Q840av models. Of course, a tant can short and cause problems.

 

[volvo242gt]

All three machines (Centris 650, Quadra 650, and Quadra 800) use the same board, the Wombat board, which had tantalum caps. The Centris 650 has a 300 ohm resistor at R151 and a processor running at 25MHz. The others have a 1.2k ohm resistor at R152 and a 33MHz processor. Some Centris/Quadra 650 boards had no ethernet port, only 4MB of RAM, and usually had a 68LC040 chip (yes, some non-ethernet Q650 boards did come with one, even though it wasn't officially listed). Most were the 8MB RAM ethernet boards with the full '040 chip.

To turn a Centris/Quadra 650 board into a Quadra 800 board, the LED connector on the side gets connected to the case's LED. I'm suspecting that a Centris 650 board will either continue to say that it's a Centris 650 board or it will be called a Quadra 800 board. I doubt that System 7.1.x will refer to it as a Centris 800 board, though. To turn a Quadra 800 board into a Quadra 650 board, you add the LED to the right front corner of the board.

-J

 

[lobust]

Yeah saw these sights. Just wanted to see if anyone had converted one before. My Q800 board just wont post past chime. No video, no scsi, nothing.. so sad to have to replace it.

I know you were following my thread on TD about my wombat board dying in the ultrasonic cleaner and how I repaired it. If you reread, you’ll see those were the symptoms of mine too. Chime then nothing.

If you are absolutely certain that U63 is working and that all it’s traces are connected, one other thing I did to mine was reflow the djemc and iosb ic’s. I didn’t mention doing that in my thread about it because I was very confident that it was the U63 repairs that made it boot, and had no real reason to believe there was any fault on those two. I mention it now as a last resort - I’d still be concentrating on U63 if I were you.

 

[imactheknife]

Ok, double checked traces, seem ok. Just dont know if u63 works, or if board works. Barn finds. The 840av had so much mouse urine and feces, a nest, and chewed wires i wasnt sure if i could resurrect that one. But she cleaned up beautifully, and is now recapped and looking great. The 800 was way cleaner, still had s nest in the case. The battery had leaked alittle and so i fixed up all that stuff. U63 was affected with some corroded legs on the corner. Reset buttons were rusty, actually really bad. So just replaced those too as they didn’t seem to function