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VectorJunkie
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I knew someone would come along and tempt me.
What Multi-kit are you going to put on them?
Can you identify this Galaxian PCB Modification?
- Thread starter VectorJunkie
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- galaxian modification
I knew someone would come along and tempt me.
What Multi-kit are you going to put on them?
Which ever one is simple and easy to build. Probably the 4-in-1 since there's no PCB required.
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VectorJunkie
Well-known member
Fixed this with Channelmanic's help. It had stopped running when being stored. It came up with garbage and just sat there. I went ahead and swapped the sockets used by the daughter cards. They were gapped and somewhat damaged anyway and he has really nice desoldering stations so I didn't want to have manually do that later.
After a minute or two with the logic probe he proclaimed I needed to swap the 74LS245 next to the CPU daughter card.
Yup, that was it. It is running just fine now. I will try to get some video posted of it running when I get it setup at home.
Thanks again RJ!
After a minute or two with the logic probe he proclaimed I needed to swap the 74LS245 next to the CPU daughter card.
Yup, that was it. It is running just fine now. I will try to get some video posted of it running when I get it setup at home.
Thanks again RJ!
Happy to help!
Glad you could make it out to the repair party on Saturday. If you weren't there when the boxes of electronic components were brought in I have quite a few still here that you can peruse through.
Raymond
Glad you could make it out to the repair party on Saturday. If you weren't there when the boxes of electronic components were brought in I have quite a few still here that you can peruse through.
Raymond
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VectorJunkie
Well-known member
What time did they show up? I went through all the freebies that were there when I was.
It was around 8:50pm or so when I left for home. Oh, and I grabbed that //c out of your office. Thanks!
Those were the boxes of new components. Not sure when they were brought in.
Also, April and Jeremy brought in some test equipment and I picked up a nice Tektronix programmable PS that is now fixed.
Also, April and Jeremy brought in some test equipment and I picked up a nice Tektronix programmable PS that is now fixed.
EWWWW...
Replace those caps and test the diodes that rectify the AC to DC!
Next, pull the transistor out of circuit so you can truly test it. It's probably not bad and you are reading through the rest of the circuit and thinking it is.
Replace those caps and test the diodes that rectify the AC to DC!
Next, pull the transistor out of circuit so you can truly test it. It's probably not bad and you are reading through the rest of the circuit and thinking it is.
esqueleto
Well-known member
Ha, Thats a photo of Vectors PCB....I have a Galaxian that was missing that transistor and I just never bothered to look it up.
mattosborn
Well-known member
That's the 78GU1C voltage regulator.
I found it in less than 60 seconds: D44VM4
Time included:
- Searching Google for "Galaxian Schematic"
- Downloading the schematic from this site... http://www.arcade-museum.com/manuals-videogames/G/Galaxian.pdf
- And finding it on page 20, the PCB layout page.
Faster than it took me to write this post.
Almost. The arrow on the pic is pointing to the transistor on the heat sink behind the caps.
mattosborn
Well-known member
Ha! You're right. My eye was drawn to the component in front of those nasty caps!
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VectorJunkie
Well-known member
I grabbed that other HP power supply that had the fried bridge rectifier. Hope to get it fixed.
I found it in less than 60 seconds: D44VM4
Time included:
- Searching Google for "Galaxian Schematic"
- Downloading the schematic from this site... http://www.arcade-museum.com/manuals-videogames/G/Galaxian.pdf
- And finding it on page 20, the PCB layout page.
Faster than it took me to write this post.
Common replacement now would be a TIP31C, cheap and plentiful
