Help with Zaxxon board issues...

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HI all :)

I got hold of a Zaxxon recently and I'm having trouble with the board in it.
I've checked all 5v, 12v & -5v, they all checked out OK.

Getting the screen in the picture attached from when I first plugged it in.
Reseated all the socketed IC's and cleaned the ones that looked pretty dirty.
Put the board back in and still getting the same screen.

Anyone seen this one before ?
 

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I don't have personal experience with Zaxxon but I think it would be helpful to have a pic of the board posted. Also, is the image static or is there any activity, moving graphics etc?

There is a very nice write up on the top of this forum section, it may be helpful to take a peek there.

Since you have done the basics, it may be time to see if there is activity on CPU, you'll need a logic probe for that... Check for the CLK signal that should be pulsing, indicating a clock signal. You may need to download the pinout for the cpu to identify the pin for CLK.
 
I don't have personal experience with Zaxxon but I think it would be helpful to have a pic of the board posted. Also, is the image static or is there any activity, moving graphics etc?

There is a very nice write up on the top of this forum section, it may be helpful to take a peek there.

Since you have done the basics, it may be time to see if there is activity on CPU, you'll need a logic probe for that... Check for the CLK signal that should be pulsing, indicating a clock signal. You may need to download the pinout for the cpu to identify the pin for CLK.

That screen is static and never changes.
Ill get a picture of the board up very soon.

Yeah I will be getting a logic probe.
 
here's a picture of the boards:
 

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Time to start poking about the board with a logic probe then. Make sure you have clock on the CPU's and see what the reset circuit is doing.
 
Recently got a GQ-4x4 programmer, today I checked all the ROM's on my board.

I checked the ROM's with the Rom Ident site and had 2 of the D2763's that seemed bad as Rom Ident didn't find any matches.
The bad ROM's were 5 & 9.
I wonder if anyone else was to pull those 2 ROM's out of their board, if they would get the same symptoms ??
Would be great if some could try it out and let me know :)

I haven't yet got my eprom eraser, so cant burn new ROM's yet.

Also ROM's 2 & 3 are TMS2564JL, the GQ-4x4 doesn't seem to support them ??
I did get a reading from both if I used the D2764 setting, but Rom Ident showed that they were for a different game ??
But not sure if that's correct as I was using the D2764 setting.
If anyone uses a different setting for the TMS2564JL's, please let me know ??

Is there anything that can be used in place of the TMS2564JL's that will be compatible with the GQ-4x4 programmer ??
 
Last edited:
Code:
TMS2564          2764
Pin(s)           Pin
2+22+27            2
  20              23
  23               2

Not tested, no warranties. ;)

This may work only for READING the contents of a TMS2564!
You cannot program a TMS2564 with this adapter, cos the TMS use a higher programming voltage (25V) and a different programming algorithm.
 
Code:
TMS2564          2764
Pin(s)           Pin
2+22+27            2
  20              23
  23               2

Not tested, no warranties. ;)

This may work only for READING the contents of a TMS2564!
You cannot program a TMS2564 with this adapter, cos the TMS use a higher programming voltage (25V) and a different programming algorithm.

Thanks for that, will give it a go :)
 
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