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Tech: Probably Dumb Questons about Reading a Schematic

I am restoring an old TRON arcade game and am troubleshooting various power issues. I just finsihed checking output voltages from the power supply, mostly good, but a few of the pin locations had notations on the cabinet's schematics I do not understand.

If anyone can help me decipher these I would appreciate it.

You can see the project here:

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There is also a diagram of the two connector locations I was testing on the power supply here:

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Here are my questions:

"A.Grnd" - From J4 (A4) - (Is that 'all ground'?) "V.Batt" - From J4 (A5) - (Something battery?) "Logic Grnd" - From J4 (A2)(B3)(C3) and J5 (B4) - (Special Ground?) "Reset" - From J4 (C3) - (I heard a rumor that this wire was key?[This is specific to Tron]) "Unreg" - From J5 (A1) - (Unregulated?What does that indicate?)

Note the "J4"and "J5" indicate the connector, the (letter/number) code indicates the position as noted on the tables here: PS Test Results Table

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Lastly, here is a link to the schematic showing the power supply. It is the board labeled,"Power Supply Bd."

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Reply to
James
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Haven't looked that the circuit, but if they follow normal convention.....

Probably Analog ground - perhaps for joystick potentiometer or speaker.

Battery Voltage.

Logic Ground - eg seperate to Analog ground so as not to put digital noise on the analog signals via a common ground.

Normally Logic Ground and Analog ground are connected together at only one point somewhere. That point is usually either in the power supply or somewhere where digital and analog worlds meet eg near the input of any analog to digital converter or preamp.

Reply to
CWatters

Awesome, thanks for the feedback!

Reply to
James

Make sure you have an NTE116 across the meter line, the feed back there freaks out the whole board. thats the same powersupply the used in dosens of different machine, it shouldn't be that hard to find one if you need a backup. Not much help, I always replaced them with a Peter Chow switching powersupply, but that would Kill your restoration.

Reply to
egotripno1

Forgive me, I am still learning. What is a NTE116, and how would I place it "across the meter line"

Might need to talk to me like I am 2...

Thanks, James

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Reply to
James

The NTE116 is a generic replacement Silicon Diode rated at 1A @ 600V

-- Best Regards, Daniel Sofie Electronics Supply & Repair

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Reply to
sofie

How would I place it accross the line? Just inline on the hot test lead?

place

there

Reply to
James

"A.Grnd" - From J4 (A4) - (Is that 'all ground'?) Analog Ground. Ground of the analog section of the circuit. This is separated from the logic ground in order to prevent ?digital noise' from getting into the audio. "V.Batt" - From J4 (A5) - (Something battery?) Yes, probably the supply from a battery. "Logic Grnd" - From J4 (A2)(B3)(C3) and J5 (B4) - (Special Ground?) Ground of the logic section of the circuit. "Reset" - From J4 (C3) - (I heard a rumor that this wire was key?[This is specific to Tron]) Can't help you here other than the obvious. "Unreg" - From J5 (A1) - (Unregulated? What does that indicate?) Unregulated. This is the rectified and smoothed voltage from the transformer before it feeds the voltage regulators. For the 15V winding, this voltage would be around 21V with the supply unloaded. The 5V unreg supply is probably from the 8V transformer winding which would be at around 11.2V when unloaded.

Reply to
Rob

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