Search found 61 matches

by alfredocalza
Fri Feb 28, 2020 11:06 am
Forum: NESdev
Topic: Undesired Jail bars on French NES and checkerboard pattern
Replies: 45
Views: 14194

Re: Undesired Jail bars on French NES and checkerboard pattern

Sorry, I was out for a while :( I had some personal issues that needed to attend to. So today I finally had some time to work on the NES and replaced the trimmer for the 26mhz crystal, but the issue was still there and nothing that I could do with the trimmer would fix the issue; I got the exact sam...
by alfredocalza
Sun Jan 26, 2020 12:21 pm
Forum: NESdev
Topic: NES-001 PPU compatible questionan issue after rgb mod
Replies: 16
Views: 3655

Re: NES-001 PPU compatible questionan issue after rgb mod

I would try checking continuity on all traces from the PPU and into the sockets on the main board. Maybe something is not properly soldered or connected?
by alfredocalza
Sun Jan 26, 2020 6:38 am
Forum: NESdev
Topic: NES-001 PPU compatible questionan issue after rgb mod
Replies: 16
Views: 3655

Re: NES-001 PPU compatible questionan issue after rgb mod

I would try to connect it to your tv through component or rgb and see how the image comes up. To avoid any problems derived from a poor cartridge connection, I would use a different type of connector. Maybe a blinking light win or just build a custom connector using a 72 pin edge card connector, or ...
by alfredocalza
Sat Jan 25, 2020 12:15 pm
Forum: NESdev
Topic: NES-001 PPU compatible questionan issue after rgb mod
Replies: 16
Views: 3655

Re: NES-001 PPU compatible questionan issue after rgb mod

j5 shorted, j3 used when nes is no fitted with external regulator (according by manual) I can remove external regulator and short j3 just for a test. Also I've to say I have no any audio from AV / or RGBnes 3.5 jack Yeah you are right, I thought it was the other way around. Looking at pictures I to...
by alfredocalza
Sat Jan 25, 2020 10:49 am
Forum: NESdev
Topic: NES-001 PPU compatible questionan issue after rgb mod
Replies: 16
Views: 3655

Re: NES-001 PPU compatible questionan issue after rgb mod

Did you short jumpers j5 and j3?
by alfredocalza
Sat Jan 25, 2020 7:52 am
Forum: NESdev
Topic: Undesired Jail bars on French NES and checkerboard pattern
Replies: 45
Views: 14194

Re: Undesired Jail bars on French NES and checkerboard pattern

Lol, I started to mess with the 26mhz crystal trimmer on the board and broke the image. Now there are strange moving horizontal lines across the picture with different colours and cannot get the image back to what it was, even if I adjust the trimmer back in the same position as before. I think I mi...
by alfredocalza
Sat Jan 25, 2020 6:29 am
Forum: NESdev
Topic: Undesired Jail bars on French NES and checkerboard pattern
Replies: 45
Views: 14194

Re: Undesired Jail bars on French NES and checkerboard pattern

Forget abut it. I just checked and I only have 17 and 21 mhz crystals, but not 26 mhz ones.
by alfredocalza
Sat Jan 25, 2020 5:33 am
Forum: NESdev
Topic: Undesired Jail bars on French NES and checkerboard pattern
Replies: 45
Views: 14194

Re: Undesired Jail bars on French NES and checkerboard pattern

I think I'm gonna end up buying an oscilloscope; I could just buy another NES for less money, but I just will not be able to rest until I find where the interference is coming from. Talking about frequencies (which I do not know much about lol), What does the 26,06 mhz crystal on the nes motherboard...
by alfredocalza
Sat Jan 25, 2020 5:23 am
Forum: NESdev
Topic: NES-001 PPU compatible questionan issue after rgb mod
Replies: 16
Views: 3655

Re: NES-001 PPU compatible questionan issue after rgb mod

Thanks for the response I have 2 cartridges: Tetris and SMB/Duck Hunt. Picture was taken on SMB/Duck Hunt, but on Tetris it is similar. I also discovered strange behavior. I'm testing on a disassembled console, without case. So, for make console read a cartridge, I have to add a little force on it....
by alfredocalza
Wed Jan 22, 2020 2:39 pm
Forum: NESdev
Topic: Undesired Jail bars on French NES and checkerboard pattern
Replies: 45
Views: 14194

Re: Undesired Jail bars on French NES and checkerboard pattern

Nope, unfortunately, it did not work!

Some pictures here:

Here is the sync separator I built:
IMG_20200122_212730.jpg
IMG_20200122_212825.jpg
Here is the CIC mod:
IMG_20200122_212717.jpg
...And here are the same old results :(
IMG_20200122_212309.jpg
by alfredocalza
Wed Jan 22, 2020 12:32 am
Forum: NESdev
Topic: Undesired Jail bars on French NES and checkerboard pattern
Replies: 45
Views: 14194

Re: Undesired Jail bars on French NES and checkerboard pattern

Well, the checkerboard pattern might be from the CIC. The jailbars won't be. You could try using the "two wires" CIC mod: https://forums.nesdev.com/viewtopic.php?p=209346#p209346 - it'll keep the CIC's clock from running, and the CIC's clock is about 4 MHz, so that could also be consistent with the...
by alfredocalza
Tue Jan 21, 2020 4:02 pm
Forum: NESdev
Topic: Undesired Jail bars on French NES and checkerboard pattern
Replies: 45
Views: 14194

Re: Undesired Jail bars on French NES and checkerboard pattern

lidnariq wrote:
Tue Jan 21, 2020 11:26 am
... I forget, have you disabled the CIC? If so, how?
Well I didn't, the previous owner did. He just broke one of the CIC's pins off. He did not even connect the pin to ground; instead he just ripped it off from the CIC. I always wondered if this had something to do with the jailbars or pattern.
by alfredocalza
Tue Jan 21, 2020 7:25 am
Forum: NESdev
Topic: Undesired Jail bars on French NES and checkerboard pattern
Replies: 45
Views: 14194

Re: Undesired Jail bars on French NES and checkerboard pattern

I think I am going to skip the oscilloscope part for now and try to see if I can figure this out without it. I read that the cpu-11 board was the most problematic in terms of unwanted interference. I will try to compare all traces on this board with those on my other cpu-07 board to see what the dif...
by alfredocalza
Mon Jan 20, 2020 3:49 pm
Forum: NESdev
Topic: Undesired Jail bars on French NES and checkerboard pattern
Replies: 45
Views: 14194

Re: Undesired Jail bars on French NES and checkerboard pattern

Also, I do not have any 1.5uf ceramic caps; I only have 1.0uf caps. Maybe I can use two of these?
by alfredocalza
Mon Jan 20, 2020 3:48 pm
Forum: NESdev
Topic: Undesired Jail bars on French NES and checkerboard pattern
Replies: 45
Views: 14194

Re: Undesired Jail bars on French NES and checkerboard pattern

Also, Is there a way of knowing if the composite video line that comes out of the PPU is picking up any noise from anywhere else? Not without better diagnostic tools than you have. A TV that accepts baseband PAL, an oscilloscope, ... maybe an AM or SW radio, but I'm not certain about that last one....