Asteroids cocktail AR Capacitors

opt2not

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Hey all, I've been working on my cocktail restoration and I've run into a confusing little tidbit.

I did a cap-kit on the AR-1 board, from Bob Robert's site he makes note of the original AR boards being shipped with 3300uf 35v for C9 and C10, and not the 1000uf's that the upright manual states. But, the cocktail manual states those caps as being 100uf 25v caps. When I picked up my cabinet, it had 1000uf caps already installed on it, but the game wasn't working.

To the cocktail owners out there, what do you guys have installed on your AR boards?

I've got three different answers to this one, and I'm confused...
 
The upright manual I have (TM-143, 3rd printing), has the same typographical error on p29 (30 in the PDF file). It describes item 23 as a "100 uf Aluminum Electrolytic Axial-Lead 24V Capacitor." That is an error. Atari P/N 24-250108 was, according to the old "approved vendor list" floating around a "Cap,Alum_Elec,1000uf,25V,Axial." The 1000µF is consistent with the schematics I have (DP-143-01 7th printing, Sheet 1 Side A).

In any case, C9 & C10 are audio output coupling caps. They might make your audio sound bad (or cause no audio), but they shouldn't keep the game from running.

Substituting a cap rated for 35V is no problem. I don't think the audio output is going to be reaching even 25V, but no matter.

So the 100µF is just a typo; the 1000µF is what the P/N and schem says; as far as the 3300µF actually being commonly installed... I don't know. I'll look at my upright; I see no reason why a cocktail would be any different from the upright as far as the AR board goes.

Oh, even though a bad C9 or C10 couldn't cause the game to not work, a shorted C13 (also a 1000µF according to the schem) COULD pull down the 10.3VDC input to the AR board and prevent it from producing a good 5V output.

I always recommend the approach of disconnecting everything, starting at the wall cord, checking with a DMM, and stepping through the wiring diagram/schematic plugging in each successive component, following the power, and checking the outputs as you go. End up verifying the proper voltages at the PCB edge connector and monitor plug.
 
Thanks for the info DarrenF.

This is actually one of two problems I'm having right now. I have a better description of what's going on in my restoration thread linked above, but the jest of it is:

I'm trying to get the game running blind before working on the monitor.

Here's what I've done so far:
On the PS I've installed a new big blue, new fuses and fuse block. I didn't change out the bridge rectifier, because the version of PS I have doesn't have one. It has 2 larger diodes on a rectifier board instead. I tested those diodes and they're good.
Testing voltages out of the PS are within range.

Onto the AR-01 board. I recapped it, replaced a burnt and crumbling diode at CR2, installed a new Power Transistor at Q2... basically everything in the cap kit. Again, got good voltages out of the board within reasonable limits.

I also recapped the PCB as well.

Plugged everything in, except the monitor, turned it on and heard only loud buzzing coming from the speakers. No game sounds at all. Checked the voltage from the test points, again all within range.

On top of that, the P1 & P2 were flashing rapid fast. At random, powering it up would cause the start buttons to flash slower, in demo mode like it should. I can press P1 to start a game (the dips are set to freeplay), and it'll stay constant which I'm assuming the game is playing.
Though it seems when I physically move or bump the pcb it goes back to rapid flashing. I'm assuming the rapid flashing means it's constantly resetting.

I'm trying to eliminate all potential problem points for either issues atm. Figured I'd make sure I have the right caps installed, especially since these caps have multiple answers I've found. I currently have the 1000uf 35v installed on the AR.
If I'm good with those, then I'll leave 'em alone. From what I read, I may have to replace the on-board amplifier, LM324N located at P11 (on the PCB I'm assuming, haven't check yet). At least, this is the closest answer I've found to the audio problem I'm having.

But getting the machine to consistently boot properly is a priority.
 
Thank you dezbaz! That eases my worries on those caps.

Given that the voltages are good, I'm going to do some more investigating into why the game isn't working. I'm going to take a look at the wiring harness tonight, the pins on the connector might not be making solid contact. Also going to take a look at all solder points, and test all diodes and resistors with my DMM.
Once this is settled, I can concentrate on the audio buzzing.
 
[I'm going to reply over here, as the other thread is in the "cosmetic" forum.]

My Asteroids (UR) AR caps are 1000µF as well. Also looks original.

You are correct about fast LED blinking being the MPU resetting (by the watchdog timer). You might take it off of free play so you can clearly tell if it's watchdogging or not.

Doing this without a working monitor is an added degree of difficulty, esp. as your audio seems to be dead too. That means no beep codes from test mode. I managed to fix my 'stroids PCB before the monitor, but the audio at least worked so I had some feedback other than the start button LEDs.

You might consider the Braze HS save kit (or hold out for the upcomming multigame kit). In addition to the HS save feature, these replace all the ROMs. Which is only a big deal because the sockets they're in tend to suck.
 
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