BTW - sockets won't fit in the case I think? I ended up removing the socket I added for RAM, but its good to have a socketed board to use for testing chips etc.
Bit of a bummer that. But as you say good to have one completely socketed PCB to keep as a test board. I have a 48K spectrum done out like that and it comes in very handy and not just for spectrum repairs.
Good god! Hard to believe last thing to swap out was the CPU! I thought you got a green screen earlier? So it looks like PPU and CPU maybe? Unless you've perhaps got a really dirty slot on the other board too, or maybe a bad connection from one of the chip swaps?
I know! I did a little testing after I made the video, I double checked all my work on both PCBs and all seems good, I cant find any broken traces or bad joints. I also tried the suspect PPU back in the faulty PCB and its back to showing a green screen. No idea why It shows nothing when tried in the good PCB. I also put the good PPU back in the good PCB and it works fine. I'll try to pull the CPUs tomorrow if i get time.
+JaysVintageJunk JaysVintageJunk It has been an interesting series so far anyway, so despite the weird faults on this one, worth the effort as it helps understanding of symptoms vs cause.
Hi. When I measure the Famicom's power adapter (barrel jack, the negative side is in the hole, the positive probe is on the outside metal of the jack), it says 13.85vdc. (input is 100v japan), if i reverse the probes it's -13.8v. There's no power I think, no picture comes out. What could be the fix? Thank you. God bless, Proverbs 31
New subscriber here.
BTW - sockets won't fit in the case I think? I ended up removing the socket I added for RAM, but its good to have a socketed board to use for testing chips etc.
Bit of a bummer that. But as you say good to have one completely socketed PCB to keep as a test board. I have a 48K spectrum done out like that and it comes in very handy and not just for spectrum repairs.
Good god! Hard to believe last thing to swap out was the CPU! I thought you got a green screen earlier? So it looks like PPU and CPU maybe? Unless you've perhaps got a really dirty slot on the other board too, or maybe a bad connection from one of the chip swaps?
I know! I did a little testing after I made the video, I double checked all my work on both PCBs and all seems good, I cant find any broken traces or bad joints. I also tried the suspect PPU back in the faulty PCB and its back to showing a green screen. No idea why It shows nothing when tried in the good PCB. I also put the good PPU back in the good PCB and it works fine. I'll try to pull the CPUs tomorrow if i get time.
+JaysVintageJunk JaysVintageJunk It has been an interesting series so far anyway, so despite the weird faults on this one, worth the effort as it helps understanding of symptoms vs cause.
Need more plug sockets Jay? Hit poundland (or poundworld, theyre in one or the other) for 0.5m 3gang extension bars for a quid.
Hi. When I measure the Famicom's power adapter (barrel jack, the negative side is in the hole, the positive probe is on the outside metal of the jack), it says 13.85vdc. (input is 100v japan), if i reverse the probes it's -13.8v.
There's no power I think, no picture comes out. What could be the fix?
Thank you. God bless, Proverbs 31
It could be lots of things. id start by seeing if you are getting 5v out of the 7805 voltage regulator.