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Arcade Collecting => Miscellaneous Arcade Talk => Topic started by: rchadd on July 10, 2005, 12:55:52 pm

Title: Are these Centipede AR2 readings ok?
Post by: rchadd on July 10, 2005, 12:55:52 pm
Hi i just been testing my "ebay untested AR2" board and happily it all seems to be working.

to test i just hooked up the transformer block to the mains and wired up the connections to the AR2 (figured that didnt want to plug in the game board just yet until confirmed that the PSU was working)

i tested the voltage using a multimeter at the variou test points on the AR2 board. here are the results:

test point  = reading
-5VDC = -5.11
+12VDC = 12.39
+22VDC = 25.9
36VAC = 38.3
+10.3VDC = 14.39

do these readings sound ok? 

i see there is adjustment pot on the AR2. with the above reading do you think any adjustment down is required? as most reading exceed the required value

safe enough to progress on to connecting the game board? as i figure next step is to measure power on the game board?

Title: Re: Are these Centipede AR2 readings ok?
Post by: rchadd on July 10, 2005, 01:03:13 pm
BTW anyone know what the +Sense and -Sense test points are for?
Title: Re: Are these Centipede AR2 readings ok?
Post by: rchadd on July 10, 2005, 04:07:14 pm
connected up the game board and tested the voltages

here are the readings

test point = reading
+5V = 5.10
+22V = 25.6
-22V = -25.9
-15V = -15.0
-30V = -26.8
-5V = -5.17
+12V = 12.32

not sure if these are ok (within acceptable range)

havent connected up to a monitor yet so unable to figure out if it is working ok
Title: Re: Are these Centipede AR2 readings ok?
Post by: RayB on July 10, 2005, 09:42:55 pm
Should be perfetly fine.
Title: Re: Are these Centipede AR2 readings ok?
Post by: SirPeale on July 10, 2005, 10:09:15 pm
havent connected up to a monitor yet so unable to figure out if it is working ok

*taps foot impatiently*

One of the best ways to see if your game is working properly, is of course to have all proper equipment hooked up.  Display would certainly apply here.  Do you have a monitor already?
Title: Re: Are these Centipede AR2 readings ok?
Post by: paigeoliver on July 11, 2005, 02:59:25 am
Those ratings look fine.

Now be sure and do the "sense mod"

    Jumper wired +Sense on ARII to 5V out of ARII )bypasses overvoltage
    Jumper wired -Sense on ARII to GND out of ARII )'frying' problem with age

This keeps your ARII board from thinking the voltage is low and overloading your PCB.

The "sense" reads the voltage coming BACK from the board, and cranks up the voltage if it is too low. All too often this fails because of wiring resistance and for other reasons and it can cause the ARII to shoot WAY TOO MUCH voltage into the board until it gets +5 back.
Title: Re: Are these Centipede AR2 readings ok?
Post by: RayB on July 11, 2005, 11:35:12 am
Those ratings look fine.

Now be sure and do the "sense mod"

Title: Re: Are these Centipede AR2 readings ok?
Post by: ChadTower on July 11, 2005, 11:49:44 am
*taps foot impatiently*

One of the best ways to see if your game is working properly, is of course to have all proper equipment hooked up.
Title: Re: Are these Centipede AR2 readings ok?
Post by: RayB on July 11, 2005, 12:00:23 pm
The variance seems tolerable.
Title: Re: Are these Centipede AR2 readings ok?
Post by: ChadTower on July 11, 2005, 12:44:35 pm
Slight unders always bother me a bit.  What does the -30V lead to, anyway?  The lights?
Title: Re: Are these Centipede AR2 readings ok?
Post by: rchadd on July 11, 2005, 02:01:22 pm
looking at the schematics the -30V test point is on the High Score Memory Circuit.

"A11 produces a 0-15V square wave at a 1V rate. This signal when +15V forward biases diode CR5 and allows capacitor C86 to charge to -29V. When the signal is 0V, CR5 is cutoff and CR4 is forward biased which causes C84 to develop a charge. C84 charges to approximately -28V. This is the potential required for EAROM C0 to operate."

doesn't really mean anything to me, i figure if the high scores are not saved then it could be a problem.

i'm sure it should be ok
Title: Re: Are these Centipede AR2 readings ok?
Post by: ChadTower on July 11, 2005, 02:07:53 pm
That's a lot of voltage for high scores... are they usually that high?
Title: Re: Are these Centipede AR2 readings ok?
Post by: SirPeale on July 11, 2005, 07:29:52 pm
There is something to be said for the prudence of not hooking up equipment to a power supply you're not sure is working properly.  The risk is much smaller to the monitor than to the PCB, but it's not an unreasonable thing for him to do.

For all intents and purposes, the monitor and PCB are two seperate entities, though working in tandem.  If you want to know if your game board is working properly, you *must* have a way of displaying it's output.  Having correct (or mostly correct) voltage isn't enough.
Title: Re: Are these Centipede AR2 readings ok?
Post by: rchadd on July 11, 2005, 07:43:34 pm
There is something to be said for the prudence of not hooking up equipment to a power supply you're not sure is working properly.
Title: Re: Are these Centipede AR2 readings ok?
Post by: ChadTower on July 12, 2005, 09:38:30 am
For all intents and purposes, the monitor and PCB are two seperate entities, though working in tandem.
Title: Re: Are these Centipede AR2 readings ok?
Post by: RayB on July 12, 2005, 11:58:14 am
He's not testing his game board.
Title: Re: Are these Centipede AR2 readings ok?
Post by: ChadTower on July 12, 2005, 01:22:33 pm

That could be the case, in which he wouldn't have much choice, unless he had equipment to generate a test load... which few if any of us would have reason enough to invest in.