Space Invaders issues

mitchomagic

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Hi,

Looking for help just managed to get my SI up and running but having issues with
the displays there is nothing showing,I have checked the fues etc,I have checked the
Solenoid Driver Board @ TP4 and have input voltage,207v and output @ TP2 nothing?.Any Ideas?

Cheers Mitch
 
I would swap the PIAs on the MPU for grins and see what happens. Then I would see if the display data, latch and blanking pins are strobing. Then you could check the voltages right at the displays. You could also check the 555 timer circuit that generates the display interrupt. Or... all of those things in an order of your choosing. That's probably not the most efficient order. Actually I would probably check the 555 timer first but it could be any of that stuff.

This assumes the machine boots and you can start and play a game but have no displays.
 
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Thanks for the reply

This assumes the machine boots and you can start and play a game but have no displays. Yes

Actually I would probably check the 555 timer first but it could be any of that stuff. Ok now Iam lost how do i check this?

Cheers M
 
Thanks for the reply

This assumes the machine boots and you can start and play a game but have no displays. Yes

Actually I would probably check the 555 timer first but it could be any of that stuff. Ok now Iam lost how do i check this?

Cheers M

Do you have a logic probe?
 
No Logic probe,

I was thinking it was more a voltage problem as I have input voltage but no output from TP2?.But I am no expert!!!!!!!!!!!!!
 
No Logic probe,

I was thinking it was more a voltage problem as I have input voltage but no output from TP2?.But I am no expert!!!!!!!!!!!!!

wow... I totally missed that. I thought you said the display voltage was good. Obviously you said the opposite of that :)
You're right... my suggestions thus far will be of no help to you if you've got no +190VDC.

You'll have to go through the 190VDC regulator and see where the problem lies.

Alternatively you could upgrade the board with something like this:
http://pin-logic.com/hivolt.htm
 
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wow... I totally missed that. I thought you said the display voltage was good. Obviously you said the opposite of that :)
You're right... my suggestions thus far will be of no help to you if you've got no +190VDC.

You'll have to go through the 190VDC regulator and see where the problem lies.

Alternatively you could upgrade the board with something like this:
http://pin-logic.com/hivolt.htm

Noooo!!!!!
Do not use a regulator that has an 'absolute maximum' rating of 125V for use in a 190V circuit!!!!
 
Noooo!!!!!
Do not use a regulator that has an 'absolute maximum' rating of 125V for use in a 190V circuit!!!!

Good to know. Thanks, Ed. I have never used one of those boards. I always just fix what's there.

To be clear... is Tom using a regulator that's rated for 125V on his boards?

Boy... I really fouled up this thread ;)

EDIT: Yup
image008.jpg
 
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Good to know. Thanks, Ed. I have never used one of those boards. I always just fix what's there.

To be clear... is Tom using a regulator that's rated for 125V on his boards?

Boy... I really fouled up this thread ;)

EDIT: Yup
image008.jpg


He is using the Texas Instruments TL783 voltage regulator. A far, far better solution than the LM317HVT that another person uses but the TL783 still not a good choice for voltages as high as what the Bally display's require.

I plan on using the TI part on my next version of Gottlieb System 1 and 80 power supplies because the Gottlieb voltages are well below the absolute maximum limits. But, to use them for the Bally, Stern or Williams high voltage section - wayyyy over the max limits.

Tom argues that the part specs are Vin to Vout limits of 125V - which is what the data sheet says. However, the Texas Instruments FAE laughed at using this part in that supply and said there are two major problems with that reasoning. 1 - If you have a shorted output then you have to dump a 300V differential between input to output which will kill the part rather quickly. 2 - At every powerup, you have a brief period where the input voltage goes to full value but the output is not yet brought up. Although it is a very brief period, it is still way over the limits. The FAE said that although it will take awhile, repetative surges such as this will eventually kill the part.

-- Ed
 
He is using the Texas Instruments TL783 voltage regulator. A far, far better solution than the LM317HVT that another person uses but the TL783 still not a good choice for voltages as high as what the Bally display's require.

I plan on using the TI part on my next version of Gottlieb System 1 and 80 power supplies because the Gottlieb voltages are well below the absolute maximum limits. But, to use them for the Bally, Stern or Williams high voltage section - wayyyy over the max limits.

Tom argues that the part specs are Vin to Vout limits of 125V - which is what the data sheet says. However, the Texas Instruments FAE laughed at using this part in that supply and said there are two major problems with that reasoning. 1 - If you have a shorted output then you have to dump a 300V differential between input to output which will kill the part rather quickly. 2 - At every powerup, you have a brief period where the input voltage goes to full value but the output is not yet brought up. Although it is a very brief period, it is still way over the limits. The FAE said that although it will take awhile, repetative surges such as this will eventually kill the part.

-- Ed

Awesome information as usual. Thanks, Ed!
 
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