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 he http://home.earthlink.net/~rescuetron/

There is also a diagram of the two connector locations I was testing on the
power supply he http://home.earthlink.net/~rescuetron/docs/pstest.htm

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 he PS Test Results Table
(http://home.earthlink.net/~rescuetron/docs/pstest.htm)

Lastly, here is a link to the schematic showing the power supply. It is the
board labeled,"Power Supply Bd."
http://home.earthlink.net/~rescuetro..._Schematic.pdf

"James" wrote in message
...

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

"A.Grnd" - From J4 (A4) - (Is that 'all ground'?)

Probably Analog ground - perhaps for joystick potentiometer or speaker.

"V.Batt" - From J4 (A5) - (Something battery?)

Battery Voltage.

"Logic Grnd" - From J4 (A2)(B3)(C3) and J5 (B4) - (Special Ground?)

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.

Awesome, thanks for the feedback!

"CWatters" wrote in message
...

"James" wrote in message
...

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

"A.Grnd" - From J4 (A4) - (Is that 'all ground'?)

Probably Analog ground - perhaps for joystick potentiometer or speaker.

"V.Batt" - From J4 (A5) - (Something battery?)

Battery Voltage.

"Logic Grnd" - From J4 (A2)(B3)(C3) and J5 (B4) - (Special Ground?)

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.

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

wrote in message
ink.net...
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.

The NTE116 is a generic replacement Silicon Diode rated at 1A @ 600V
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -



"James" wrote in message
...
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

wrote in message
ink.net...
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.

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

"sofie" wrote in message
...
The NTE116 is a generic replacement Silicon Diode rated at 1A @ 600V
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -



"James" wrote in message
...
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

wrote in message
ink.net...
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.

"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 he PS Test Results Table
(http://home.earthlink.net/~rescuetron/docs/pstest.htm)


"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.