| Arcade Collecting > Restorations & repair |
| Vendetta PCB repair |
| << < (2/4) > >> |
| Mike A:
I went back to the schematic and then ordered the correct amp from eBay. I will explain how to do that in another thread. I want to try not to side track too much for the meat of any particular thread. I will post links to reference them when necessary. It should create a web of good information. |
| Mike A:
I soldered in the new audio amp and I had to make a heat sink. My metal working tools and skills are basic. With a better jig I will be able to make a nicer one...Or I can just by some aluminum U channel in the appropriate size. It is a skill building and learning exercise. If I skip anything that you want to know more about just ask. I will continue this later. I need to write up my JAMMA explanation and some other things. As you can see I am terrible and cleaning up after myself. Now I have good sound FX , but the music is scratchy and wrong. That is not totally surprising because the ROM that handles that stuff is the one that tested bad. So progress but not success. |
| Mike A:
The next step was to address the bad ROM problem. I didn't have a ROM programmer so I couldn't directly test the ROM. I put in a call to bperkins01. He told me to check traces going to and from that ROM. He told me that if there was bad communication with the chip, it could be okay and still test bad. That I can do. And that is why it is important to reach out and make friends in this hobby. There are a bunch of people who will gladly help you out. I told him I already checked the traces. He said check again really close. There it is. That tiny spot broke continuity for that trace. |
| Mike A:
The next step for me was to see if fixing that trace would fix the problem. I just took a 18 or 20 gauge wire and soldered it to a point before the break and a point after the break. I found suitable spot by continuity testing large enough solder points. I figured I would do a cleaner fix later if it worked. One of these magnifiers is a pretty essential tool for finding broken traces and stuff. Especially on these later boards. The traces are smaller and closer together. Did it work? |
| Mike A:
Yes it did. The music and sound now work perfectly. Hooray. I asked bperkins01 (you will see his name pop up a lot) how these things are normally fixed. It was a small break so he said to scrape the spot with an exacto, to use some flux and then make a solder bridge. Well I was not crafty enough to do that. I made the gap wider. :P Next I tried using a tiny bit of wire to bridge the now wider gap. :P I ---smurfing--- suck at this. I ended up using some tiny 30 AWG Kynar wire to bridge the trace at the same points I originally used. It looks much better now, but not as professional as the other techniques would have been. I put the PCB back in the machine and had my buddy's kids play test it for a couple of hours. The repair has been solid. Victory. I will post pics of the final repair sometime later. I forgot to do that before I put the PCB back in the machine. |
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