Ramakers Posted February 12, 2013 Share Posted February 12, 2013 Hello, I've got meself a AV Famicom for free, but there's nothing like a free meal. It was told to be broken, so i opened it up to find some problems. As I thougd the power convertion seemed to be blown. I replaced the LM7805 and its 1000uf con. Now I have clean 5.0 volt on all the right places. But if I connect to a tv set I only get a white screen? Is there anything else I can test to know what might be wrong? Regards, Noel Ramakers. Link to comment Share on other sites More sharing options...
mamejay Posted February 12, 2013 Share Posted February 12, 2013 You may not be in much luck mate. From what I have found the AV famicom does not have fuse like the original famicom. Possibly an incorrect polarity PS was used and fried things further up the line. I did have a faulty AV famicom which I fixed by replacing the voltage regulator. I have had white screens before and from what I have found it is a fried PPU unit which would need to be replaced. Not sure if its work the hassle. You could possibly butcher a normal Famicom for the PPU and do a transplant. Link to comment Share on other sites More sharing options...
Ramakers Posted February 13, 2013 Author Share Posted February 13, 2013 I've been looking at the schematics and found the sound to be directly wired from the cardridge to the output. So if anything is working there must be some sound coming from the speakers? Or is the PPU also responsible for requesting sound from the card? Link to comment Share on other sites More sharing options...
mamejay Posted February 13, 2013 Share Posted February 13, 2013 That I do not know. SOrry Link to comment Share on other sites More sharing options...
epicfatigue Posted April 9, 2013 Share Posted April 9, 2013 you are going to need to use a logic tester to see whats happening on the ppu/cpu see if there is any activity at all, this will not be a simple fix. I have seen sometimes the reset gets held in and you require to build a circuit using a 74hcu etc. Take it to a pro or keep it for spares is my advice otherwise go buy a scope or logic tester you can get some cheap second hand ones for 300ish now Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now