Seriously tore up my top loader attempting to remove the PPU
Posted: Fri Aug 04, 2017 7:06 pm
I'm a fool. A moron. I failed to heed the warnings that the PPU had some solder points that needed tons of heat to work, and rather than be more careful, I got in a hurry. I tore up traces, and broke pins off of my PPU.
I have since gone through as carefully as I could and jumped all of the damaged traces I could find, and installed the dip socket that came with my NESRGB board - but I must admit that I am in over my head. I get a black screen when powering up - but if I use my multimeter to check the composite video signal, I get what amounts to 1Vpp, which if I understand it correctly, is a proper voltage for a composite video signal. I get black screen from composite video, svideo, and RGB.
I have installed the PPU into a second socket that it will permanently live in, dremeled part of the package itself away and soldered wires to the exposed copper to repair the chip as best as I could. I get 5v at the NESRGB board.
Here's a bunch of pictures of the disaster I have created. I am acting out of paranoia at this point checking continuity all over the place, using this pin map:
Right away I'm concerned, because I don't have continuity from pin 3/D1 on the PPU to pin 10/D0 on U1 (sram) - but I have bridged continuity D1 to D2 on SRAM, and D2 on the PPU has continuity to those two points - however no continuity D1 to D2 on the PPU itself. Very odd. :\
Anyway - here's the pictures of where I am with this:
http://imgur.com/a/8EgIZ
Halp. I can't tell if I have killed the PPU or not. I don't currently own an o-scope or logical analyzer, and from what I can tell a replacement PPU will run me $60. At that point I could almost afford to just buy a new one and start over.
What can I do here? Right now I'm just matching up pin names and testing continuity out. Finding things that leave me confused, like the PPU diagram I have shows pins 14, 15, 16, and 17 as R, G, B and I assume sync (it's black). Yet from my pictures, it looks as though 14 and 15 were bridged, and 15 and 16 were bridged, and all 4 have continuity to ground, so that's what I reproduced as best I could.
As you can see, I'm floundering here.
I have since gone through as carefully as I could and jumped all of the damaged traces I could find, and installed the dip socket that came with my NESRGB board - but I must admit that I am in over my head. I get a black screen when powering up - but if I use my multimeter to check the composite video signal, I get what amounts to 1Vpp, which if I understand it correctly, is a proper voltage for a composite video signal. I get black screen from composite video, svideo, and RGB.
I have installed the PPU into a second socket that it will permanently live in, dremeled part of the package itself away and soldered wires to the exposed copper to repair the chip as best as I could. I get 5v at the NESRGB board.
Here's a bunch of pictures of the disaster I have created. I am acting out of paranoia at this point checking continuity all over the place, using this pin map:
Right away I'm concerned, because I don't have continuity from pin 3/D1 on the PPU to pin 10/D0 on U1 (sram) - but I have bridged continuity D1 to D2 on SRAM, and D2 on the PPU has continuity to those two points - however no continuity D1 to D2 on the PPU itself. Very odd. :\
Anyway - here's the pictures of where I am with this:
http://imgur.com/a/8EgIZ
Halp. I can't tell if I have killed the PPU or not. I don't currently own an o-scope or logical analyzer, and from what I can tell a replacement PPU will run me $60. At that point I could almost afford to just buy a new one and start over.
What can I do here? Right now I'm just matching up pin names and testing continuity out. Finding things that leave me confused, like the PPU diagram I have shows pins 14, 15, 16, and 17 as R, G, B and I assume sync (it's black). Yet from my pictures, it looks as though 14 and 15 were bridged, and 15 and 16 were bridged, and all 4 have continuity to ground, so that's what I reproduced as best I could.
As you can see, I'm floundering here.