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Vanløse, Copenhagen, Denmark
Mathematician. Working programmer/system developer. Nerd. Married. Father of 3.


V-System Aero Fighters Repair Log

As many of the people who know me personally might have discovered, I'm a big fan of the shmups made by Psikyo and V-System. So I was very pleased when I was able to snap up a cheap original defective Aero Fighters on evilBay };-P The listing text said "only small graphic error during play", and already when unpacking the PCB from the box, I got a strong feeling of what might be wrong with this poor PCB.

It had a corner full of rot (corrosion)!

And at the bottom of the box, I found this

the main smoothing cap for the 12V rail. However, I tried to connect the board anyhow, to see how much damage this rot made to the actual game.

Many of the graphic elements in the intro and in-game, had stripes through them. This is often caused by poor pin connection on either RAM or ROM ICs. The ICs in the rotten area are MASK-ROMs, so I was pretty sure I'd found the culprit causing these errors. So I decided on desoldering the 2 MASK-ROMs with the "V-System"-logo on the silk screen.

I can't say that the sight that met me underneath the desoldered ICs was pretty }:-S So I started by giving that part of the PCB a good scrub with rubbing alcohol

and a toothbrush

That actually did fix up the PCB a lot, but it didn't remove all the rot

Now I didn't quite know what to use, but I had this can of WD40 };-P

So I sprayed the infected area, waited about 5mins to let it work, and then started rubbing the individual circuit tracks with a swap.

After that I gave it a good scrub with rubbing alcohol and tooth brush again, as WD40 is oil based, and that actually made the area look a lot better };-D
Next I went through the area with my continuity tester checking the tracks, and found two broken. Both of them were at places where the track had a via on it, and then only one end made proper connection. So I carefully scraped a bit in the via holes with a Stanley knife, uncovering a little bit of copper. I then took a piece of kynar and stuck into the via hole from the parts side, used a lot of liquid flux

and soldered it into the via hole from both sides

The other ends of the kynar, I just stuck into the normal PCB holes.

That way, they'd get soldered in place automagicly, when I soldered in the sockets for the MASK-ROMs };-D And here is the final result, with the sockets (header strips) fitted

and from the solder side

Hard to see just how rotten this corner was just a while ago };-P The MASK-ROMs themselves, also had a scrub with WD40 and rubbing alcohol, and actually ended up looking quite decent.

As a last thing, I needed to fit a new smoothing cap for the 12V rail. I didn't have one as big as 2200uF, so I dug up the biggest one I could find

and just fitted that

And last but not least: The Big Test };-P

I'm very pleased to say, that game now plays perfectly; one more original V-System shmup added to the collection };-P


  1. little off topic, but which parts do you replace most often?
    or rather, which parts do you tend keep on hand because you replace them the most?

    1. Hmmm, that's a little hard to say. I think mostly different kind of SRAMs and TTLs...I have a huge pile of scrap boards that I usually source parts from (not electrolyte cap, but most other parts). Only if I can't find them there, I buy a small stock usually from eBay (China) or buyicnow.com

  2. Job Well done .. Hvor får man fat i de sockets du bruger??? Du kan få noget der hedder el-rens med smøring fra Unican (c-65) sådan du slå to fluer med et smæk næstegang he he jeg bruger det selv når jeg renser prints.

    1. The sockets I use are (usually) called 'breakable header sockets' and I source them from Chinese sellers on eBay (being sure to keep the price on a batch below 80DKK, to avoid customs). I like using them because:
      1) they are universal in the sense, that they can be used for any size of IC.
      2) the pins are the round type, so they make very good contact.
      3) because it's separate strips, they leave a lot of the PCB accessible after fitting.
      4) they very cheap.

      I always try to find the cheapest buy-it-now with free shipping at the given moment. Last time I got them here http://bit.ly/10Pnt3w

  3. Thanks for the Info... Sockets are now in order.. Saw you had the eprom burner, could you program some eproms for me ? My mail is anders.lubeck@gmail.com

  4. No, I don't do programming services. But I know that http://arcade-shoppen.dk/ have just recently started to do so. So as you're located in DK, you might want to try them };-P
    Btw I've recently added a contact link at the bottom of the page...

  5. Hvor ville jeg ønske at jeg kunne finde ud af den slags. Hvor fedt at kunne restaurere den slags gammelt guld! Hvordan har du lært om elektronik nu da du er programmør by trade? Kan du anbefale nogle elektronik lærebøger?

  6. Translation of question:
    "How I wish that I could figure out this kind of stuff. How cool to be able to restore this kind of old gold! How did you learn about electronics, now that you're a programmer by trade? Can you recommend any electronic textbooks?"

    Hmmm, first of all thnx for the kind words };-P
    I'm afraid this post might be a little long };-D
    You're not the first one to ask me this, and I'm not quite sure what to answer.
    Ever since I was a child, I've been interested in how things work internally, taking my toys apart and so on. Also I've done many small projects of eletrical, electronical and mechanical nature with my father when I was little; he's is in many ways just as curious as I am about things work };-D ... and the fact that I've not been stopped, has of cause been a big motivating factor for me then and is now.
    I got my first soldering iron at about the age of 10 or so and my first electronics experimental kit around the same time.
    Later I had electronics in school and also went to Technical Gynmasium (HTX) with electronics as special instead of normal high school. On top of that, I have a cand.scient. degree in mathematics with a minor in computer science from the University of Copenhagen.
    About the arcade-rep thing, I've collected arcade-PCBs for about 8-9 years (also a lot of defective ones), and about 2½ years ago I decided, that I wanted to start reparing them. So I started googling and quickly found some fourms where peolple publish their own rep-logs. Some of them are very detailed and comprehensive, and I learned a lot from them. I really recommend Wombles logs (from AussieArcade; see link to the left). When I get to a stop in a project, I've never been afraid to ask, and on some forums people are very friendly.
    So no, I'm afraid I haven't got any recommendations for textbooks, but try googling };-P

  7. Thank you for your reply. So basicly you are a smart guy and I'm probably too old and stupid to catch up :) :) I think maybe I should have chosen HTX instead of HHX, which was very boring.