Quoted from mg81:Personally, if I see a game is hacked but it works it does not bother me very much at all. I will make a big deal out of it to try and get the price lower, but it does not bother me. I figure I can always pretty it up later if the hack starts to go bad.
My goal is a machine that plays well and if a hack is working and not damaging anything I don't normally rush to "fix it" until I am doing other work in that area when something actually breaks.
What really does scare me is a hacked machine that is dead. If a hack happened and the pin never worked again I can see myself having a pile of time trying to figure out what is wrong. Wires all mixed up, wrong parts put on boards, someone could have mixed up wires and put high voltage through all of the chips and they are fried, etc. A pile of time could be put into a game like that to get it working again and it may not be worth it.
I had a friend go out and buy an old non-working Comet without checking with me first. Had all sorts of spliced in wires and mismatched colors. They subbed in lamp cord and had such a useless loop of splice that once I traced it around they had (probably by mistake) bypassed the game fuses as well.
You're right, it is time consuming to undo the foreign stuff but it has to be done. It will make the game much easier to troubleshoot later when it physically matches the schematics. Get a notepad and break it down in sections (for example - I'm going to work on correcting the G.I. section) Study it well and make good notes and you'll get it fixed- just maybe not as quick as you would like.
If I was to purchase something questionable, such as a box with a corrosion damaged motherboard, I'll figure in the "what-if-I-end-up-actually-having-to-replace-this-board" cost into my offer. If it's a dead game but original boards never worked on and no corrosion, I'll pay up on that game, because it's something I can work with easily.