It is currently Wed Dec 13, 2017 10:07 am

All times are UTC - 7 hours





Post new topic Reply to topic  [ 2 posts ] 
Author Message
 Post subject: NES Video Problems
PostPosted: Tue Jun 06, 2017 11:49 am 
Offline

Joined: Tue Feb 14, 2017 11:39 am
Posts: 5
Hello All,

I've got a couple issues with this NES I'm trying to track down. First is garbled video. There are frequently chunks missing from sprites and sometimes sprites are missing all together. For example in the video below, half pills and half viruses appear when trying to play Dr. Mario. This happens on any video output, composite, HDMI (yes, I'm installing a hi-def NES to complicate the matter). I've tried several different pin connectors from known good NESs. I've even tried with a Blinking light win but nothing resolves the video problems. I've continuity tested the pins on the edge connector on the motherboard to the next via or connection point. I've also continuity tested the pins of the PPU and CPU the same way.

The other issue I'm having is specifically through HDMI on the Hi-Def NES output. The image scrolls to the left over and over. The Hi-Def NES configuration menu is rock solid in the center of the screen like it should be, but the NES images still scroll behind it. This started after I replaced the caps in the video amp/power module to see if they were perhaps the culprit of the above garbage video issue (not the cause apparently). I've tested through the old composite video and the scrolling doesn't exist.

https://youtu.be/HXKywZcRmb0

As always, any insight/assistance is greatly appreciated.


Top
 Profile  
 
 Post subject: Re: NES Video Problems
PostPosted: Tue Jun 06, 2017 12:18 pm 
Offline

Joined: Sun Apr 13, 2008 11:12 am
Posts: 6513
Location: Seattle
That left scrolling crawl is something related to the 2C02's normally missing pixel. The HDNES is supposed to intentionally omit four master clock cycles to the PPU whenever it notices the missing pixel, but for whatever reason it's not working for you.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 2 posts ] 

All times are UTC - 7 hours


Who is online

Users browsing this forum: bazza and 10 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group