So another week goes by and my Jet Fighter board has another failure, these 40 year old 74 series logic seem to be dropping on a regular basis from being powered on for a few hours here and there...
This this when I started a game, the scores didn't reset to '0' for either player, when I scored some 'hits' on the other Jet the score moved in an odd sequence something along the lines of 2,3,2,6,4,11.
Out comes the operation manual and my printed schematics. The scores are initially generated by two identical circuits comprising a 7493 binary counter, Pins two and Three which are linked to the 'START' signal are used to reset the counter to zero when the game starts. Pin 14 is the counter input which is pulsed when either Jet is 'Hit'. The output pins hen count upwards to a maximum of 15 and pass on to some more circuitry.
Jet Fighter Score Counters
After playing a few games I noted the following... the score was being reset every time a game was started, just not to zero, and it was actually counting, just not in a sequential order, I made the assumption that these two counters would not be the issue as having two different IC's fail at the same time was improbable, If one of these had failed it would seem more likely that one of the scores would stop working and not both at the same time.
The next part of the circuitry that relates to the scores is shown below:
Jet Fighter Score selecting
The 74157 at location A5 receives the signals from the two 7493 counters. I used my logic probe to test the pins of this IC. Pin 1 was pulsing away as expected and the input pins were all the in the same logic state as the output pins from the 7493 counters. There are four output pins used which feed into a Prom which selects the Score number data, by my testing, pin 12 which is output 4Y on the datasheet was stuck high all the time. Quickly piggybacking a new 74157 cured the scoring, but did seem to have a side effect of resetting the game a short while after stating a new game. Anyway once socketed, I put in a new 74157 and we're back to fully working again. My IC tester confirmed that output 4 of the IC was faulty.
Well after close to four years, all the cabs I own are (touch wood!) working, Well I need a new starter for my Tempest Fluorescent light, but thought I best capture them while they all do work. My current line up consists of:
Fire Truck, Jet Fighter, Electrocoin Midi with a dual JAMMA adapter playing Pac-Land & Wonder Boy, Tempest Cabaret, Centipede Cabaret, Hang-On and Pole Position.
On the way to getting my current lineup I’ve also owned the following cabs: Lethal Enforcers, Cruis’n World, Missile Command Cabaret, Asteroids Cabaret, a Popeye Pachislo & 2 JAMMA cabs.
Photos below and a video, sorry for the lack of commentary but I’ve got a stinking cold at the mo and the vocals don’t sound too good.
This board failed on me back in March, and I briefly looked at it but didn't really have the enthusiasm to fix it at the time, fast forward six months and here we go again...
So upon re-testing the boards, the X axis output had stopped working, this was caused by a failed TL082 at location D/E12 on the main AVG board, pin 7 wasn't outputting anything, I fitted a new socket and replacement IC and had a stable output again, back to where I was six months ago.
Last week I got stuck into this fault again, (Crazy vectors and Showing Mathbox error in test mode) I have spent a good few hours probing with a scope and logic probe to try and track down where the issue was, I got the schematics printed onto A1 paper at work, I even de-soldered all the proms from another Tempest AUX board to double check my proms had verified correctly, which they had.
Now, convinced that it wasn't a Prom/Bitslice/Socket or Interlink cable, I honed in on the remaining IC's in the Mathbox area. E4 a 7408 (quad 2-Input AND gate) got my attention, now I'm not really proficient enough in fixing boards to understand what was wrong but pin 6 which drives the clock input of B1 (374) didn't look pulse correctly on my logic probe, the frequency of the pulsing was all over the place and the HI/LOW LED's were going 'mental' in an odd way. I tried piggybacking a known good chip onto the 7408 to no avail, not deterred I de-soldered it and put a socket on the board. I then tested the IC in my Programmer which also tests 74 series logic, and sure enough one of the gates reported faulty. I put a new 7408 in and BOOM! The game is working again!
I have ordered new TL082's, MC1495's, trim pots for X/Y size/position adjustments and will fit these when the arrive to hopefully improve the reliability of this board, but for now I think I'm due a few credits. :)
So I just got back from a family in North Wales, I visited a few arcades and found them full of redemption machines, pushers and it has to be said a good stash of new sit down drivers and an Afterburner Climax cab.
I never spotted a 'classic' machine on my travels, but I did stumble on a machine that was new to me; Animal Kaiser. At first from a distance I thought it was a new Sega Dino/Mushi king type cab upon close inspection it is a Bandai Namco cab. The game in a basic form is player one vs computer or player one vs. player two. You are an animal and you battle against your opponent. You only have two buttons, one chooses your attack and the other chooses the attack strength. Simple enough but, there is added excitement that after each game you get a game card which can be used in you next game. There are three types of card: 1) A red 'Animal' card, If you have one of these you can play with that animal in your next game. 2) a Green 'Strong' card that increases the power of you attacks and finally, 3) a Blue 'Miracle' card which acts as you special move.
When you start a game, you scan one of each card if you have them and that combines your strength and health and special attack. The games consists of three rounds (If you last that long) fighting a different animal each time with the big boss in round three. The game is like a skill stop selection, your first button press chooses your attack type which is dependent on your cards, and next button is the power of the attack, the game then takes over and shows you being attacked or you attacking the other player depending on who had the best attack. The idea is to knock their health down and wipe them out. Whether you win or loose, you get a new game card at the end of the game. As the name goes all the cards are based on different animals and in true collecting style some seem to be plentiful and others can be Gold/Silver & Bronze 'Rare' cards and one card is labelled as 'Ultra Rare' which is the character with the most strength.
I was amazed in the evening that these machines were packed with kids wanting to play all night long, at one pound per play these machines would have been making the operators a very good return. Not just that but there was a real buzz around the game and who had which card, a classic moment for me was when a small girl came up with her dad, he got some game cards out of his wallet and as she scanned them there were real gasps and cheers from everyone as she scanned the Ultra Rare 'Seigfried' card, this will be an awesome moment in my arcade memories as it was great to have my kids really getting a buzzing arcade experience. Lots of very jealous kids standing by in anticipation watching her game! We all had smiles watching, but she didn't make it though all three rounds even with one of the best card.
Between myself and my two kids we spent about £50 on the game over seven night, we got a few of the rare cards and the kids now want me to get a certain machine for the home arcade. lol.
From researching since I've been back these machines have been around a fair while with these cabs having 2007/8 copyrights over them. This game was labelled revision four which is new in the UK, but there seem to be at least another four versions that have been released worldwide to date. See below for a few photos and a video of Son number one playing. Each game lasts around five minutes which in today's arcade, combined with the fact you get a card is pretty good value entertainment in my opinion.
After watching the games being played for a few days one finally ran out of game cards which needed an Op to open the cab up and put in some new cards, I took a few blurry photos as you can see below. There were 600 cards in the box and they were labelled as A,B,C & D. I couldn't tell if they went into different compartments and wonder if certain packs contained the Animal/Strong/Miracle cards etc.
Game cards in the box above, and the (blurry) service menu in the photo below.
Our card collection, including a Gold Rare and some Bronze Rare's.
If you want to find out where you can have you wallet emptied there is a map on the Facebook page that shows current game locations in the UK.
So the cab is now as complete as I'm going to make it. If I had more space I would do some cab woodworking to fix the broken corner then finish off with new T-moulding, but for now this is it.
A can of black satin spray was used to cover the new section of MDF at the bottom of the cab along with the recently made back door, the finished result can be seen below.
Another item on my list of thing to do was to make a cardboard monitor surround which site in between the front glass and monitor, I had no original surround for this so I made so I slowly measured and cut the card, the final result came out OK, not perfect but better than without one.
I finally got round to spraying the coin doors and fitting some new reject labels. I took three attempts at spraying the doors, mainly due to the fact I didn't sand and clean them well enough to begin with!
To finish thing off on the cab I finally applied the steering wheel sticker I bought a while back from arcadefixit.com
In true Pole Position style the game board has gone belly up just as I finally get things finished! After having a few games recently the cab decided that it wouldn't coin-up or go into test mode even though attract mode was still happily playing. Upon re-powering the cab I am now greeted with a blue screen full of zero's :(
*Update1* Mark at Retroclinic fixed the board set for me, I lasted a few weeks before failing again.
*Update2* I am now going to wait for Adam Courchesne to finish his Pole Position clone board before dropping any more money into this cab/
Well after have a fair amount of play recently and being switched on for 10+ hours, Jet Fighter developed a fault when switched on a few days ago...
In attract mode the Black Jet was erratically flying backwards, not something I'd seen before with this board. When you started a game the Black Jet carried on flying backwards and the left/right rotate controls we not working for either Jet.
I started probing around the vertical and horizontal motion counters to see if I could track down the issue, there are four signal J1C0-J1C3 which are derived from a 64-bit RAM IC, probing these for the Black Jet circuit I found that they were all stick high and not pulsing as I would have expected.
This board is quite nice as the Black & White Jets have pretty much identical circuitry so it was easy to compare one with the other.
Checking out the other pins on the RAM, I found that the W/E pin was being held high, I traced this back to an LS7432 (2-Input OR gate) and confirmed that the output was stuck high (confirmed against the White Jet circuitry). I cut the output pin on the 7432 and was still stuck high and not pulsing away. Once swapped out with a replacement, The game is fully working again.
Schematics showing the area of the fault this time.
