Atari Canyon Bomber Restoration

[greedycrisp]

A mistake I made was having the coin door powder coated initially. The completed door is pretty but doesn't look right on the machine.



Taking it apart and repaint it and the other powder coated parts starting Friday, will do multiple coats through Tuesday or so. I usually use the spare-bathroom shower-curtain bar as a drying rack but the wife's not at home so...



At least I did the painting outside.

 

[greedycrisp]

...

 

[greedycrisp]

The side art has several mars and scuffs, worse on the other side I think. Current plan is to finish everything else, color match, then go back in with air brushes possibly this winter. We will see. The redone black makes the image pop a bit more, Im preserving the original over-sprays and paint 'mistakes' , as in not touching those up.

One thing that will push me to complete the painting is the control panel. I had handed this off for someone else to do the paint restore and had forgotten the exact state of it. Now that I re-examine it I'm crushed.



I'm by no means good enough to repair the paint on this to the degree I want to. I have no idea how to repair the scratched areas well enough to blend it in, other than taking everything down to bare metal. I'll have to study up and devise a plan.

 

[greedycrisp]

This took far too long. Due to the contour of the existing panel I couldn't trim the new laminate after installation so I cut it before. There's probably a smarter way to do it, as it was I feel I wasted an entire day.

 

[lilypad19]

Nice work

 

[greedycrisp]

This side of the cabinet is worse than the other.

• The cabinet was scraped across something in the past, smearing the image in several places.
• The machine was strapped too tightly for a move at one time leaving a clear mark.
• Loss of a foot caused the front corner to partially break off and the remaining corner material has been worn down.
• In a few places, drops of water sitting on the surface expanded the wood and disturb the artwork.
• Edges of the vinyl are chipped exposing the wood below.
• Couple of places have poor attempts to repaint.

This is why I wanted to hand off the cab to someone else to do the artwork. Sigh.





And, someone was painting another cabinet white while it was standing near this one splattering small drops of white paint across part of the cab. (Ok, that last one might have been me, not sure.)

 

[greedycrisp]

Restoration of the image itself will wait until winter. Meantime step one is simple green with a micro-fiber rag to remove as much grime and paint drops as possible. Exacto knife to remove spots of paint that don't come off with simple friction of the rag. Don't use magic eraser on these Atari cabs, it removes the gloss finish.



The broken corner luckily effected very little of the image.



Wood hardener is applied to the exposed area. Clamp the wood off at a simple-to-reproduce angle. Slice the finish with a blade, cut down with a dremel blade. I only had metal-cutting blades on hand so it burnt more than cut. Remove the wood using wood chisels and mallet.

 

[greedycrisp]

I wasn't able to find the exact vinyl that Atari was using so I need to experiment with materials. Vinyl wraps and the usual laminate suspects weren't close enough. Best results so far are sealed pine with multiple coats of black gel stain but im not satisfied yet.



So, determine the depth needed to fill the void. Cut one form carefully, verify it fits the space, then plane some wood to depth and replicate copies of the form. This will let me experiment a bit with the finish process and see which gets closest. Drill some dowel holes in the back of the patches. Perhaps overkill but I'll be routing the area later, want to give the adhesive the upper hand against a router.

 

[greedycrisp]

While the corner plugs are going through paint and stain tests, moving forward with the rest of the side. Taping the image off takes a lot of time.

 

[greedycrisp]

Yesterday turned into metal work stuff, today will be more. As the back of the control panel is now missing I had to harvest parts from junk control panels and derust them. Today will be zinc plating those and the other pieces I had wire brush.

Prepping bolts for oxidizing.



This morning was first pass on the side panel, applying window glazing with black tint to the cuts and blemishes.



A few of the places I did should probably be wood filler. I have to do a filler pass anyway so I may go back over those.

And, checking the color match on the corner patch. Close enough for the bottom of the machine. I'll epoxy it in after the paint thinner fumes have cleared.

 

[greedycrisp]

Coin door rebuilt for second time. This is as far as it goes besides adding a lock.



Somehow Ive gotten 13 more plays on the counter . Hmm.

 

[greedycrisp]

Completing the PCB, troubleshooting the power conversion on the board.

The board appears to function properly with 5V DC applied just past the voltage regulator on the far side of the resistor. With 5VDC applied voltage drops to 4.66 to far side of board.

The original power supply is solid, rebuilt last year and putting out 11.79 V DC. The voltage regulator system is taking it down to just over 4 volts with the 2 Ohm, 20W DALE resistor is doing an impression of Fukishima. I know these get hot, but wow. I'm thinking to replace it with a 4 Ohm, 50 Watt resistor and see whats happens.

 

[cwilkson]

Don't modify anything. Moving from 2R to 4R will make things worse. Sorry. Super in a hurry atm.

350mV is a lot of drop.
Something is probably borderline failing on the board.

I'm swamped until the weekend but let's talk before you waste a lot of time on power. I'll dig up a CB manual and get back to you.

 

[cwilkson]

Really quick test:

1. Pull the LM323 and 2 Ohm, 20W "power heater" from the board.
2. Apply +5.25 VDC across C35 (220 uF, 25V).
3. Measure the current draw of the PCB...during attract and during game play.
4. Report back.

 

[ArcadeTechGW]

Don't modify anything. Moving from 2R to 4R will make things worse. Sorry. Super in a hurry atm.

350mV is a lot of drop.
Something is probably borderline failing on the board.

I'm swamped until the weekend but let's talk before you waste a lot of time on power. I'll dig up a CB manual and get back to you.

I agree with this. If you have a thermal camera, look at the game board for what is glowing almost as much as the resistor. I'm thinking you have a weak rectifier in the circuit which is pulling too much.

 

[greedycrisp]

Really quick test:

1. Pull the LM323 and 2 Ohm, 20W "power heater" from the board.
2. Apply +5.25 VDC across C35 (220 uF, 25V).
3. Measure the current draw of the PCB...during attract and during game play.
4. Report back.

1 & 2 are done

In attract mode, feeding 5.25 VDC across C35 is pulling 3.146 amps according to the PS, close to what it was pulling the same as when I was feeding it 5 VDC. The far corner of the board is now reading 4.818 The board's been running in attract for about an hour, nothing is notably heating up. A couple of the chips are at 110 degrees, most are at 90 something, the CPU is cool, nothing on the board I cant touch.

Is 3.146 excessive?

I dont have a buttons on the test harness so I havent tested it duriing gameplay, if that is necessary t0 get a reading Ill mod my test set up.

I did note that the legs on the 'power heater' resister were crudded up good. I measured resistance at 1.6 ohms, then cleaned the legs, then read 2.1 Ohms across it. Wondering if just that mount of gunk effected my prior readings. And, wondering if trying to clean gunk from other chip legs would be helpful or inviting problems.

 

[ArcadeTechGW]

1 & 2 are done

In attract mode, feeding 5.25 VDC across C35 is pulling 3.146 amps according to the PS, close to what it was pulling the same as when I was feeding it 5 VDC. The far corner of the board is now reading 4.818 The board's been running in attract for about an hour, nothing is notably heating up. A couple of the chips are at 110 degrees, most are at 90 something, the CPU is cool, nothing on the board I cant touch.

Is 3.146 excessive?

I dont have a buttons on the test harness so I havent tested it duriing gameplay, if that is necessary t0 get a reading Ill mod my test set up.

I did note that the legs on the 'power heater' resister were crudded up good. I measured resistance at 1.6 ohms, then cleaned the legs, then read 2.1 Ohms across it. Wondering if just that mount of gunk effected my prior readings. And, wondering if trying to clean gunk from other chip legs would be helpful or inviting problems.

Depends on the gunk.
Rust: Clean
Green corrosion: Clean
Haze on Tin: Clean
Tarnish on silver: Leave alone.

 

[greedycrisp]

I left the PCB running for hours in attract mode last night & the house didn't burn down so I presumed everything past C35 wasn't doing any harm. Cleaned the legs on the original resistor and reinstalled. Installed one of these in place of the LM323 regulator as I had it on hand. PCB now works on power from the original power supply. Voltage is 10.03 at the edge connector, 5.19 following the space-heater resistor, and 5.16 at the far end of the board.

I'm assuming the gunk on the original resistor was preventing power flow from my DC power supply from getting into the board, accounting for the voltage drop I was measuring, and that he LM323 was bad or shorted somehow, causing issues when feeding it with the OEM power supply. Will leave it running and wire up controllers to test out sound and gameplay.

The wire wound resistor put off a lot of smoke, presumably burning off dust I hadn't completely cleared out of it. Its still pretty hot. Any value in replacing with a newer resistor type with a higher wattage rating?

 

[cwilkson]

That doesn't make any sense. The resistor drop doesn't have anything to do with the drop across the board.
That's a function only of the trace resistance and the on-board current consumption.

10.03 V seems slightly low. Check both rectifier diodes to make sure they're ok!
And check the brick wiring to see if you're getting excessive drops from transformer to filter cap and from the BFC to the LM323 input.

The resistor should only be able to supply about 2.5 amps. The LM323 has to make up the difference. If your LM323 was weak, the 5V output would be low as a result.

These linear power supply things drive me nuts! There's no reason to start replacing things without understanding root causes. And absolutley no reason to start redesigning things (except when parts are no longer available - the only exeption!)

Again, I can't go super detailed now. Wish I had time for an andrewb style wall of text.
If you have time this weekend, let's have a Zoom call to pinpoint your real issue (or issues) and solve them.

PS. Smoke is normal on the power resistor. It's burning off the gunk and it will go away eventually.
Ideally it's dissipating about 13W so yes, it will get very hot. But it's well within the component's design spec.

 

[ArcadeTechGW]

That doesn't make any sense. The resistor drop doesn't have anything to do with the drop across the board.
That's a function only of the trace resistance and the on-board current consumption.

10.03 V seems slightly low. Check both rectifier diodes to make sure they're ok!
And check the brick wiring to see if you're getting excessive drops from transformer to filter cap and from the BFC to the LM323 input.

The resistor should only be able to supply about 2.5 amps. The LM323 has to make up the difference. If your LM323 was weak, the 5V output would be low as a result.

These linear power supply things drive me nuts! There's no reason to start replacing things without understanding root causes. And absolutley no reason to start redesigning things (except when parts are no longer available - the only exeption!)

Again, I can't go super detailed now. Wish I had time for an andrewb style wall of text.
If you have time this weekend, let's have a Zoom call to pinpoint your real issue (or issues) and solve them.

PS. Smoke is normal on the power resistor. It's burning off the gunk and it will go away eventually.
Ideally it's dissipating about 13W so yes, it will get very hot. But it's well within the component's design spec.

I'm aligned with what you said, except if the resistor corroded into the solder joint, you could be taking a voltage drop before the resistor.

I assume you have one of these that you can benchmark, but if that resistor is dropping voltage, it will get hot. It's just the science of it. The power is dissipated as heat.