bought a pong machine from ebay and need a little help

[omf]

ok i had one of these when i was younger or rather my parents did and let me at it http://www.ebay.co.uk/itm/252584920795and i manage to break it so it got thrown out, now i decided to get another to have a go with.

 

so i found the above on ebay and purchased it as it was quite cheap etc.

 

the description said they the guy cant test it, so i thought thats because he has a new fancy flat screen that would not be compatible with rf and thought that after plugging it into a crt it would be fine. so when it arrived i tried this and it just outputs bad noise, it sounds like the ball is moving between two walls that are 5mm apart if you can imagine that type of noise.

 

i took it apart and it looks like some batteries had leaked and possibly some electrolytic capacitors have leaked.

 

i can get new capacitors as they have values on and try those but there are other components that i dont know what they are.

 

i have tried to look for schematics and diagrams for this specific model but there dont appear to be any as such apart from a pinout of the processor it uses which is basically pong on a chip.

 

does anyone know of any schematics for this specific item so i can see a parts list etc?

 

i have my friends atari pong machine in bits too as im putting in a composite mod so it can be played on a new tv, my aim it to eventually do the same with this

 

i will add innard pictures later when not at work

 

thanks

[Hyperboy]

"Guy can't test it" = broken but seller doesn't want to put that in the listing.

 

Sent from my non beer holding hand.

[omf]

"Guy can't test it" = broken but seller doesn't want to put that in the listing.

 

Sent from my non beer holding hand.

thanks for that completely unhelpful comment there

 

i have had items described the same that actually worked fine so i thought i would give it a go.

[Keatah]

First order of business is to clean all the acid and corrosion. And replace the capacitors - a good idea anyway because of age. Then clean up other components. But be sure and photograph the corrosion before starting so we know what leaked where.

[Hyperboy]

thanks for that completely unhelpful comment there

 

i have had items described the same that actually worked fine so i thought i would give it a go.

Not knocking you dude, if you buy it as untested and you are cool with what you paid then who cares what I or anyone else thinks. Many, many of us on here would have told you the same thing as a precaution for future purchases. I hope it works out for you, it's always nice to resurrect a vintage console.

 

Sent from my non beer holding hand.

[omf]

innards damage

[+sramirez2008]

I like Sharleen. Hope you can get her working again!

[omf]

I like Sharleen. Hope you can get her working again!

of that i have no doubt, the question is when

[Keatah]

Some of that is battery leakage. And believe it or not, some of that is adhesive used to tack down parts. There's flux left over from mfg. There might not be any electrolytic cap leakage - hard to say with 100% certainty - despite it looking like a mess there. I bet that crap came from elsewhere. And the Green caps don't leak.

 

 

Maybe in the next day or two I can outline what I think is what and post the marked pics back. Meantime:

 

In any case - I've repaired far far worse than this. Much worse. Is this cleanable and repairable with basic tools and chemicals? I'd say yes.

 

The variable pot may need to be replaced - depends how it cleans up and ohms out. I think the carbon resistance trace will be eroded or not connected to the pins that solder to the board. That's the semi-U shaped bit of circuitboard material sandwiched between metal pieces, like a clutch on a car. It's about 1.4cm in height. It's right next to the square transformer.

 

I'm counting on the wax sealer/filler/potting material to have protected the variable inductor coil (the square silver thing with a red screw).

 

The green chicklet mylar caps appear to have been glued together with adhesive - and are now split apart and contaminated..

 

There's some glue on the IC.

 

There's more contamination here than what I believe would come out of the blue electrolytic cap.

 

The solder side looks alright and contaminant free. And I even think some of that "gunk" is lube grease from the rotary switch.

 

And a no brainer, the battery contact will need attention, replating or resoldering, whatever.

 

We'll just have to address each component one by one. This is *THE* fun and joy of repairing and restoring classic gaming equipment.

Edited November 2, 2016 by Keatah

[Keatah]

I'll really try to hit the pics and ID the parts and type of contaminant, by Thursday night.

[+Stephen Moss]

 

i can get new capacitors as they have values on and try those but there are other components that i dont know what they are.

 

 

If you can get some good images of the components you can't identify someone might be able to identify them.

Looks like someone has run solder across the top of the processor to link to pins - what a bodge!

[Keatah]

Nope. That isn't solder. That's simply stray adhesive. No harm there.

[omf]

capacitors and cpu sockets ordered

[Keatah]

Not sure a chip socket is needed. But it won't hurt..

[omf]

Not sure a chip socket is needed. But it won't hurt..

well as i have my friends working atari pong machine with a socketed cpu i thought that it would be another thing that could be tested to rule it out as the problem so it makes life easier

[Osgeld]

you pose more risk to the pcb to remove the chips to place sockets, just touch them up with a little fresh solder if there is a possibility of a cracked joint

 

it wouldnt hurt if you were fairly savy with electronics repair, you stand a good chance of destroying either the chip or the board trying to remove it if you are not

Edited November 4, 2016 by Osgeld

[omf]

i have tonight installed a socket and replaced the electrolytic capacitors and installed a known good cpu chip

 

unfortunately it still makes the same racket as before

 

i think the next point of interest should be that pot or that coil thing with the square round it with the red tape - i dont know what that is

[+Stephen Moss]

i have tonight installed a socket and replaced the electrolytic capacitors and installed a known good cpu chip

 

unfortunately it still makes the same racket as before

 

i think the next point of interest should be that pot or that coil thing with the square round it with the red tape - i dont know what that is

 

If you are referring to the metallic square object in the top center image that looks like a tunable/variable inductor, if you are referring to the item in the top right and bottom left images that looks like a small transformer which are often used for couple in audio circuits.

 

Have you checked the power supply and clock oscillator (if there is one) are operating correctly? Always a good place to start because if either of those is at fault you have no change of logically finding any other problems.

Edited November 8, 2016 by Stephen Moss

[Keatah]

That pot looks nasty, at least it should be ohm'd out.

[omf]

 

If you are referring to the metallic square object in the top center image that looks like a tunable/variable inductor, if you are referring to the item in the top right and bottom left images that looks like a small transformer which are often used for couple in audio circuits.

 

Have you checked the power supply and clock oscillator (if there is one) are operating correctly? Always a good place to start because if either of those is at fault you have no change of logically finding any other problems.

I am referring to the non silver thing

 

the power supply was batteries but I wired it to my DIY eBay china variable power supply to give it 9 volts, it doesn't output massive ampage but is enough to power the Atari pong variant. for example it doesn't output enough power to run an Atari lynx. I guess I could find a more powerful power supply and give it a go, I guess that could be an issue as well.

 

im hoping that transformer cube hasn't died, I don't know anything about those and will have a hard job finding a replacement.

 

there Is no crystal / oscillator that I can see anywhere unless there is one hidden in the rf modulator shielding box, not sure how its getting a clock signal without one, perhaps the chip has one built in, I know chips like the attiny85 do have one built in but they are relatively slow and can accept greater speeds but you have to supply your own to get those speeds.

[omf]

That pot looks nasty, at least it should be ohm'd out.

it looks like it is stamped with a 1K so I would say variable up to 1000 ohms, I have not as yet tried to measure it, looks like I would need to measure both legs with centre to get the resistance of both sides

[omf]

I have a crappy capacitance meter that I measured some of the old capacitors I pulled off and they are not as specified on them so looks like they had failed.

the 1uf capacitor from underneath the board actually read 335nf, or what that 0.335nf, it was too low anyway

[omf]

OK it is time for me to pick this up once more and try to get this working.

since last time i have a much batter power supply which is capable of 5 amps, obviously that isnt needed here but the machine may need a little more than was offered by my previous power supply i was using

 

when powered the machine was powered up the sound that cme out of the speaker sounded correct, so i hooked it up to the tv, i couldn't get it tuned in 100% but from the slow scrolling image that it i could get i could see that the pong game was in fact functioning correctly.

 

so the problem seems to be the rf output

 

so i'm hoping i can cobble together a cheap composite mod to basically bypass the rf output maybe take the signals directly from the chip. doing this you do get some degree of brightness difference from the separate output pins from the chip however but it is an option

 

 

there is a variable resistor or variable capacitor in the rf modulator box that i could adjust, im a bit loathed to adjust that pot on the board as it is already in bad condition

[virtvic]

Depending on what 'pong on a chip' it uses, you can mod them to display thru an AV port (yellow of the red, white and yellow) I did this with mine and it gives a great picture.

The old pongs are pretty simple things, so you should get it working fairly easily.

 

Good luck with it.

 

[omf]

Depending on what 'pong on a chip' it uses, you can mod them to display thru an AV port (yellow of the red, white and yellow) I did this with mine and it gives a great picture.

The old pongs are pretty simple things, so you should get it working fairly easily.

 

Good luck with it.

 

yeah this was what I cobbled and it worked. I did this also to an Atari pong and that is what gave me some brightness difference

 

mine however looked ok. the whole bodge setup slipped and I lost video, i'm not too bothered by this however as the Atari pong did the same and it was ok after re adjusting the wires

after I lost video I re tested the audio by reconnecting the speaker and it was still making correct sounds so I am quite sure the main processor did not die during the said bodge board slippage.

 

 

there are various schematics around to get composite from the ay-3-8500 which is the chip I have, the above seems to work the best, all the others pretty much don't work

 

I am also going through a transistor to increase the power just as a precaution. which I used the details for an Atari 2600 mod. http://mrpjevans.com/wp-content/uploads/2014/05/Transitor-mod-watermark.jpg

 

I did attempt this http://atariage.com/forums/uploads/monthly_02_2012/post-23476-0-04916800-1329682515.gif although it makes more sense to me to protect the hardware, for some reason it does not work

this was taken from the thread at http://atariage.com/forums/topic/194029-av-modding-a-pong-uniteven-possible/

 

its rather annoying that the pong chip requires about 7 volts to work and the transistor wants 5 which increases the components (ie voltage regulator and capacitors) to ensure smooth voltage but as the transistor requires like 30ma to function the regulator doesn't even need a heatsink at 9 volt

 

its a bit weird that it does not have a crystal. this signal appears to be generated by various other components