My new addition to my personal Arcade

[Twincharge]

Just got myself an Atari Asteroids Cabaret Arcade Machine. Considering this is a 31 year cab, it is in remarkable condition. It is complete and completely original, still has the Electrohome vector monitor in the cab.

At the moment it is non-working, but I suspect a bad PSU or PCB issues. I am working to get it working again, once done I will give it a full restore which it deserves;

[JonEp]

Those pics bring back great memories lost in the arcade I wish I had space for one here.

Always wanted to buid a MAME box in a cab too.

[plug1]

That is so fucking sweet dood
i love the atract mode on that machine.......... (do`s it have game over burn)
i have a 1970 pinball (willians travel time), a sonic fruity and a sega rally stand up ..

if you need help getting back on its feet give me a shout .

when you plug it up do you get power to the head board and the coin slot bulbs ?

[Twincharge]

At the moment I am getting power to the marquee, P1 and P2 buttons flash, neck on monitor is glowing but the spot killer on the deflection board has kicked in to prevent damage, either an issue with the PSU or game PCB.

Will update my progress.

plug1 - nice line up of cabs by the way.

I also have the following;

2 Electrocoin Spectrum JAMMA cabs (One vert other Horz)
Sega Outrun Mini
Sega Afterburner
Sega Super Hang On
Namco Starblade

[ZX7R]

That is very cool.

- Are you married and if yes, what does the wife think?
- Considering the footprint of each cabinet, where the hell do you store them?

[lithho]

put some pics up of the others pal please, i had a pacman coin op, lovely it was

[Twincharge]

Yes I'm married, and just hit 40. However, as I told the missus, she should be grateful I'm not chasing young women instead like most men at my age.

All of my cabs were non-working when I got them. luckily I do have skills which come in handy to bring these things back to life. The biggest challenge was the Namco Starblade, it is huge and not many of these things left in the wild.

The cabs are currently in my man-cave which is the garage, that is except for the Asteroids which is in the 'workshop' (conservatory).

Yes, will get some pics up of the cabs.

lithho - what happened to the Pac cab?

[russbeer]

whereabouts in Merseyside are you Twincharge? I'd love to give Starblade a whirl for old times sake.

[Twincharge]

whereabouts in Merseyside are you Twincharge? I'd love to give Starblade a whirl for old times sake.

Im actually in Warrington now, stones throw from IKEA, you are welcome to have a blast on Starblade.

[russbeer]

bugger. I was there on weds.

thanks for the offer, next time i'm heading that way i'll drop ya a pm

[tronads]

I have horrible memories of lifting a full size Asteroids cab up a flight of stairs (West Coast Rock cafe, Blackpool) with my mate, when I did a stint working for a single site operator.
Those things are bloody heavy !

[plug1]

Yeh bud how you getting on with ya astroids , can you get the test pattern up ?

http://arcarc.xmission.com/Tech/Aste...idsrepair.html

Hope this helps.

[Twincharge]

Yeh bud how you getting on with ya astroids , can you get the test pattern up ?

Thanks dude for that link.

Progress has been slow to be honest as I have been busy with other things at the moment like getting the house in order.

I have not even got as far as trying to fire it up as of yet, as I wanted to overhaul the Power Supply components before I even attempt to fire it up.

As you can see, the Power Brick was quite a mess, full of dirt and corrosion;



A closer look;



After a good brushing session, things were looking much better but nowhere near clean enough;





As usual with these Atari Power Bricks, the underside has fared much better, you an still see the beautiful gold/brass finish of the metal which has long since gone on the top surface. This Asteroids was an early version, since the Power Brick uses two discrete diodes instead of the more common bridge rectifier on the large smoothing cap (Big Blue);



After a good cleaning and sandblasting session, plus a generous coat of Hammerite Gold Smooth, things are looking sooo much better. I also replaced the large smoothing capacitor known as the Big Blue;





More progress to come very soon.

[Twincharge]

Due to the cold weather, I have been putting off looking at the Asteroids cab since it is in the conservatory and bloomin cold in there. Therefore, I came to the conclusion that I should move the cab into the house for the duration so at least I do not have to contend with the cold.
Turned out to be a good move as I have progressed a bit.

The first thing to do was to finish off cleaning the wiring loom and then re-install the PSU brick back into the cab. Once the PSU brick was back in place, I disconnected all the plugs on the PSU brick except for the 240v AC in, Interlock and the 110v supply to the fluorescent tube. This was so I could start to test voltages being thrown out by the PSU brick.



First thing I noticed was a very low hum coming from the transformer, the fluorescent tube flicking on and a quick flash from the corner of my eye coming from the PSU brick fuse block.

Yep, the very first fuse on the top of the fuse block (7A) had blown, not a great start. I was getting 0v DC from pins 1,2 and 3 on the 15 pin connector block.



Hmm, the first thing I thought was if I had gotten the polarity wrong on the Big Blue. Now, I checked it and double checked it. But these days, I leave the house in the morning then wonder if I shut the front door behind me....grrr!!

So I removed the PSU brick again from the cab and checked the polarity of the Big Blue, nope it was correct. However, I did spot the problem right away, school boy error alert ;



Yep, the short is obvious now, but why I missed that I will never know. Corrected;



With the short removed and the PSU brick re-installed, I set about re-measuring DC voltages again on pins 1,2 and 3 on the 15 pin connector block. All three measured at 13.99v .

Continuing, I measured AC voltages now, these measured at around 6.5v, 37v and 67v which looks about right. Phew!

Next on the agenda was the AR board which looked quite clean;



First thing to do was to replace the larger caps on the board, so a few minutes later;



I am now ready to test voltages from the AR board, but not today, instead I thought I would have a look at the Asteroids PCB. It looked quite clean but has been repaired at some point, check out the repairers label;







Obvious previous repair;



I did spot a problem though which I cannot understand how it happended. One of the components (C57) on the PCB had been torn away from the PCB from one side, I have since resoldered it down;



Next I will be testing the AR voltages and maybe trying to fire up the PCB.

I plugged everything back together, with the exception of Monitor and the PCB and fired up the cab. Luckily, the AR voltages checked out fine, so next I plugged in the PCB to check the load voltage on the PCB.

I could see the LED on the PCB light up, so we definately had power to the PCB. However, the voltage turned out to be on the low side, around 4.5v DC, so I cranked up the pot on the AR until we got to around 5.05v DC.

Looking at the front control panel, the P1 and P2 buttons were blinking rapidly, so things seem to be pointing to the PCB at the moment. Still, Im pleased with the progress.

We also had a look at the underside of the control panel, definately needs a good cleaning up, and those buttons and leaf switches could do with being replaced;



Coin Mechs;



I think it may be time to have a closer look at that PCB and maybe get the Scope out to see what is showing on the XY side of things.

[Twincharge]

Next I removed the CPU 6502 from the socket, the legs were very dirty but came up good with a good rub with a fibreglass pen. I also re-seated the Eproms, these look new however and seem to have been replaced recently.

If you look carefully at the images of the PCB, you will see what seems to be a thin layer of an oily substance coating the PCB. It is more apparent on the Eprom labels which have absorbed the oil or whatever it is.

Firing up the PCB after this however gave the same results.

I therefore decided to knock out the Scope and see if anything is going on with the XY output. This is the first time I am using the Scope and hope I have set it up correctly. I connected the Red probe to the X-Out and the Yellow probe to the Y-Out on the PCB. I only grounded the Red probe to the PCB as I did not think I would need to also ground the Yellow probe?



Anyway, I selected XY mode on the Scope, but I saw nothing, just a dot in the centre which shows by default;



Something bizarre did happen though, all of a sudden the sound effect of the Asteroids ship constantly firing kept repeating itself over and over, and with this both the coin meters on the coin door went crazy and started to count up with each firing sound! Made a right racket and the damn thing made me jump! Problem is pointing to bad game PCB - doh!

Ok, so PCB is bad, first I have to check the ROMs.

I did just that, not making massive leaps here at all, but at least eliminating stuff on the way. Read all the EPROMs on the PCB and threw them through WinROMident to see if they were good;



All checked out good, so problem is elsewhere.

To date, I have replaced the two 2114 RAMs on the program side with sockets and fresh RAM, the original items were badly rusted.











I also removed and socketed the 74LS42 at L6, isolating pin 1 (DMAG0) in order to try and determine what is causing the watchdog resets.

Anyway, I fired it up, and noticed that the game was now playing blind. All sounds were present and perfect, so at least the sound circuits are fine. However, the game did crash after a couple of minutes, with the repeating firing sounds and the coin counters going crazy as per previously.

So there is a problem on the MPU and VSM stages (game & vector).

I did however notice something, the cab was in TEST mode, how come it is playing blind?? I confirmed that the cab should not play at all when in TEST mode.

Hmm, seems like either the TEST switch is faulty or the wiring to the TEST switch is at fault. I removed the TEST switch and using a Multi-Meter, was able to determine that the switch was working fine, however the switch had been wired incorrectly. I'm not sure if an operator had removed it at some point and incorrectly wired it back up, or if it was wrong from factory.



Anyway, I wired it up correctly and replaced the TEST switch back into the cab, now when I fire the cab up in TEST mode, I get the following four tones, HI, HI, LO, LO. Seems I have more RAM issues??

Manual says

1 - D2
2 - E2
3 - M4
4 - R4
5 - N4
6 - P4

So 3 and 4 LO = M4, R4 ram faults?

[Twincharge]

So I removed, socketed and replaced fresh 2114 RAM at M4 and R4, replaced the PCB back into the cab and re-tested.

Problem was, I was no longer getting the TEST mode or anything. Seemed the board was no longer responding, apart from the odd beep or hum. Pressing the Reset button on the PCB just gave random results.

I then swapped out the 6502 CPU with a known good CPU, no change.

Hmm, I then re-tested the voltage with the Multi-Meter onto the PCB to measure the +5V and found that the DC voltage was fluctuating wildly from around +4V to +5V. I immediately disconnected the PCB from the edge connector and found the +5V copper trace was very hot. So hot in fact that the heat had lifted the copper trace from the PCB surface.



Damn, so I set about repairing this right away using some strong resin glue;



My attention now turned to the edge connector, this must not have been making good contact creating resistance which in turn made the AR crank up the volts to compensate cooking the +5v trace;



Looking at the +5v and GND edge connector pins, I could see the problem right away. The pins were badly corroded and worn. So bad they were that when I tried to prise one of the pins to add more tension for a cheap bodge it just snapped with ease. These top four pins will definately need to be replaced before I can continue troubleshooting the PCB. Eventually I will replace all the pins;



Moving on, while I was socketing the RAM at M4 and R4, I make a habit of using a Multi-Meter in Continuity mode to ensure there has been no shorts created during soldering caused by over-spill.

Problem is, while doing this the Multi-Meter showed continuity between pins 16 & 17 on the RAM at M4, infact, since all four RAMs are connected in parallel they were all showing continuity at these points. Im pretty sure this should not happen, so I double checked my soldering on M4 and R4 and it looked fine.

Question is, what is causing this short? Could it be another bad RAM at N4 or P4 (which I have not replaced) or another IC which is causing the short?

Below is an old picture which does not show the new sockets and RAM at M4 and R4, this is just for illustration to the problem;



So I carefully removed the new 18-pin RAM socket at M4, also removed all the other Vector RAM (N4 & P4) but I am still getting continuity at pins 16 & 17. The Vector RAM is shorted somewhere but I have not found the cause yet.

I did however find another problem, the Vector EPROM 24-Pin socket has been replaced at some point with a new one, however the soldering job was not so great as I found a broken trace going to pin 23;



The RAM traces looked fine so seemed likely to be an IC which has gone short circuit. Checking the schemes for the RAM I found out that Pins 16 & 17 are address lines;



I therefore checked the 74LS244 and 74LS255 IC's.

I was pretty sure the Vector EPROM socket was fine apart from the broken trace coming from Pin 23, but I double checked the traces again for shorts or open line.

[maltloaf]

I found an asteroids board set years ago in an entertainments company junk box. I got it up and running on an oscilloscope, but not before fucking it up (and repairing) with wrong A/C voltages.

Good luck mate, I loved playing with stuff like that in the past.

Currently I own

Star Force cab
super off road 3 player cab
track and field mini cab
turbo outrun cab, with original outrun boards in

also a shit load of pcb's including pacland, cobra, hunchback etc.

[Twincharge]

I had another look at the Asteroid schemes and noticed that those two address lines go to the Vector ROM Pins 1 and 23.

Then I remembered that the trace for Pin 23 was damaged, surely the short must be under here?

Anyway, I removed the socket and this is what I found;



In the image above it looks as though the solder pad for pin 1 has lifted, but it has not I assure you. Its just a glob of old dull solder.

I repaired the trace and replaced the ROM socket.

This would explain the problems with the RAM.

I have since removed the short (Pins 1 & 23) and the RAM address lines on Pins 16 & 17 on the 2114 RAM are no longer tied.

It has been a bit slow as I have had to do some major reading up, particularly the schemes for Asteroids and play around with my scope.



Turned out the problem was a bad RAM octal buffer DP8304BN at E3, this controlled the MPU RAM and the TEST was reporting a bad RAM at MPU stage even though I knew they were good.

So I swapped the BP8304BN with the one in P2 (Vector RAM buffer) and the TEST then revealed that there was a bad RAM at the Vector side, even though I knew they were good also (I had replaced them previously).



I had made some assumptions that the DP8304BN would be compatible with 74LS245 and had previously replaced both the DP8304BN to eliminate them. This caused the issues of random noises coming from the cab and in constant reset, although the TEST mode worked but constantly repeated itself due to reset after one cycle.

So, 74LS245 is NOT compatible with DP8304BN, at least not the ones I have.

I can get the PCB playing blind with DMAG0 (vector side) disabled now, re-enabling the DMAG0 still lets the PCB play blind until it tries to access a bank of vector RAM inaccessible due to the bad octal buffer (DP8304BN).

So, just need to wait for some of these DP8304BN's to arrive now.

[Twincharge]

Spent a fair bit of time with the PCB over the weekend, I resorted to using the piggy-backing method to see if I could stop the PCB reseting.

Since the PCB had run without disabling DMAG0 for a few seconds initially when I solved the RAM shorting and buffer issue, I thought it was probably just one IC that had failed.

I struck lucky as I found a bad LS193 counter at H5, so I desoldered the bad LS193 and put in a socket and a fresh LS193. PCB now ran without disabling the DMAG0!

So I got the scope out again and hooked it up to the XY on the PCB, all i got was a thin vertical line in the middle of the scopes screen. However, when I looked carefully I could see the there was varying levels of brightness in the line and things appeared to be moving along the thin line. Switching to TEST presented me with a static line. Again, moving to the game mode the line appeared to have activity, I could see what looked like bullets moving quickly along the line when I fired in a game.



Looked like I was looking at a squashed screen, I had no X deflection. So I de-soldered the DACs for X and Y and placed some sockets on the PCB. I then swapped the DACs and I now had a thin horizontal line, Y deflection gone but X was now present.



I knew at that point that the DAC originally for X was bad, so I swapped it out and got this image in TEST;



A TEST pattern! Looked a bit fuzzy though, this is the sharpest I could get it using the FOCUS knob on the scope. I then switched to game mode and got this;



ASTEROIDS!!!!

However, the screen still looked fuzzy, I could not see the ATARI copyright at the bottom or the scores at the top, the Asteroid ship appeared to be a bright dot. I adjusted the X and Y pots and did see some improvement in scaling but still no scores or ATARI copright message at the bottom.

Also, the screen in attract mode appears to be bouncing by about 5mm up and down every second, not sure why.

So, I replaced all the ICs in the Output stage, which were the TL081's, TL082's and the 4016's;



The noisy fuzzy image is now replaced with a much sharper image;



Game mode;



Much better, but screen is still bouncing in attract mode (did'nt try actual game play) and still cannot see the Asteroid ship which appears to be a dot, and no scores or ATARI copyright message either.

I was not sure if this was due to the limitations of the scope, so decided to go for it and fire up the monitor for the first time.

I expected to hear a crackle but heared nothing, the screen appeared to be dead, no life at all. Looking at the deflection board I saw no LED (Spot Killer) lit. No chatter from the deflection (not that I know what it sounds like) but the neck on the tube was glowing.

At this point, I called it a day, I really did have enough.

[Twincharge]

Next day I ran back and fired her up, and played with the VOLTS per DIV for both channels and got the pictiure looking 100% like Asteroids, bouncing has now gone, hitting the THRUST button the Asteroid ship emerged from behind the bright dot in the centre of the scopes screen. So, the dot is being generated by the scope, I assume this is due to lack of Z input?







So PCB is working for now, I had tried to fire up the monitor but it is dead, time to repair it.