The hunt is on!

The parts came in! So now I have 2N3716 & 2N3792 replacements for the power transistors that drive the vector monitor yolk. These are the ones mounted on the case in TO-2 cases (metal).

I also had MU-07 and MU-57 on hand, and Mouser had MSP8098, it's a replacement for the TIS98 that is used throughout the deflection amplifier circuitry.

So I pulled all these transistors on one of the G05-805 monitors that I have, soldered in the new parts, checked the TO-2 packages to make sure they weren't shorted the collector to the heatsink and turned everything on. The spot killer is still lit up. I did a little sleuthing and realized there's a 2N3906 that's pretty integral to the deflection circuitry and it's the only transistor that I didn't replace, so I swapped those out as well.

No joy, the monitor is still dead. So at this point I have done the following:

• Cap kit
• Swap all deflection transistors (MU-07, MU-57, TIS98, 2N3906, 2N3716 and 2N3792)

So now I need to start looking at resistors and diodes, and the fact that perhaps I have damaged some of the transistors. Both the X & Y deflection circuits are behaving the same, so perhaps that's an important clue.

Coming along

I got a chance to spend a little time with the Asteroids today. Turns out I had a spare 2N3055 transistor, it was part of the Williams power supply get well kit. Since I have gotten rid of the Williams games (Defender & Stargate), I made good use of it in the Atari AR1. Now I have my Asteroids board working with the proper Audio/Regulator board, on to fixing the monitor.

I have two G05-805 (15") B/W vector monitors. I didn't think either would work but they are both failing in the same way - the spot killer is on. I suspect it's the XY drive transistors (the 2N3716 and 2N3792) but don't have any spares so it's time to place an order. I also plan to pick up a replacement for the big capacitor in the power supply, and a knob for the volume control. It would be great if I could make an extension cable so the monitor doesn't have to be so close to the motherboard, I'm working on locating the parts I need to do that (I have the monitor-end, I need the motherboard-end).

So it may be a few days before I get the parts I need to make any more progress, in the meantime I brought in the top glass for the cocktail table and I'll start cleaning things up.

It's alive! Sort of...

I had some time to work on the asteroids game. I've pulled it all apart, cleaned it up some, and assembled it on my "work bench".

You can see in the upper right corner my Zektor ZVG. I use it to drive a 19V2000 vector monitor so I can play all the vector games using VectorMAME. This is also a convenient way to test monitors out with known good signal sources.

Atari Audio Regulator 1

Notice the Audio Regulator, it's an AR2, though an Asteroids cocktail needs an AR1. The AR1 was producing the correct voltages until it was under load (connected to the other board), then the +5V supply dropped to about 1V, which isn't going to work. I remembered I had an AR2 laying around, and it's pin compatible with the AR1 (though much larger and produces more voltages from different molex connectors). This brought the board right up.

My next step was to hook up the scope and see if the Asteroids board was indeed working. After looking at the 6MHZ test point (good) and seeing good stuff on XOUT and YOUT test points, I opted to set the scopy in XY mode. I could see a very crude Asteroids display. Next step was to plug in the 19V2000, and Asteroids was alive!

Now I'm not out of the woods. I have to get the AR1 working, and the cocktail doesn't fit a 19V2000, I need to get the 15 inch monitor working. But a lot of things are working.

I think the AR1's problem is the 2N3055, that's the big power transistor on the heatsink. The LM305 is regulating voltage, it's just when load is applied that the voltage drops, so hopefully this will be a simple fix. Before I compose an order to Bob Roberts I'm going to snoop around and see what else I might need so I can make one order. For now I can use the AR2 (though sadly I don't have any sound), and the 15" monitor will now be my main electronics focus.

I should mention I have two Asteroids mother boards, and one of them is not working, so at some point I'm going to need to work on that problem as well.

Asteroids Cocktail

So I've started the restoration of the Asteroids cocktail. I purchased the cabinet with no mother board (and I didn't notice at the time but missing the Audio/Regulator board as well), with the assurance that it all worked. I had no belief it would work given a new board set, and regardless I want to strip it down, clean it up and do a proper, if not exhaustive, restoration job on it.

Above is a view of the inside of the cabinet. Now that I have boards this is "parts complete", so the work that needs to be done is to tear it all apart and then clean things up. I will need to get everything working, but I'll do that outside of the cabinet so I can have more control and access to the components. This means pulling out the power supply. I have to decide how far I'm going to go with this restoration, I'm thinking of stripping the power supply apart and refinishing the metal.

Thankfully the outside of the Asteroids cabinet is black so I won't have to search all of Christendom for matching wood grain contact paper like I had to for the Pacman restoration.

Starting from scratch!

It finally happened, the herd has been thinned. I posted in various forums that I was giving my collection away. The state of the hobby is such that I received very few takers, and only one that said he'd come straight away and take all that I would give him. Jim Melcher (see www.melchman.net) was eager to help me out and showed up at the appointed time with 3 helpers. They made quick work of the loading up the games and assorted spare parts. Here's what they got:

• Defender
• Stargate
• Lunar Lander
• Breakout
• Space Invaders
• Battlezone
• Missile Command (cocktail)
• Space Duel (cocktail)

In addition I threw in (all for free!) a G05-802 vector monitor and a color XY monitor. Jim also took the Fluke raster TV pattern generator off my hands. I also had two Lunar Lander mother boards (working!) that Jim got to haul away. And I even gave them some of my home brew beer. I better get accolades in his blog. I'll keep in touch with Jim and see how he progresses getting the games fixed.

There are only two games I kept, a working Pacman cocktail (which I restored), and a non-working Asteroids cocktail. So with only two games in the herd, and one of them fully restored I can focus all my attention on Asteroids.