AES to PVM via RGB - Intermittent picture curl at the top of the screen

[wyo]

The problem seems to occur when the screen flashes white during a game or there is fast action with bright colors at the top of the screen.

Here is an example from Super Sidekicks' attract mode:



I don't have this problem with my SNES or Genesis, also connected via RGB. They use composite sync, whereas the AES uses composite video for sync. My AES is a low serial number US Gold System with original (ie. wrong) capacitors and resistors. Whites seem overly bright on the AES but overall color is quite muted. I'm going to hook up my other AES to see if it has the same issue and will also try both via composite video.

Any ideas in the meantime?

 

[Xian Xi]

Just swap the caps when you get a chance. That's what causes it to do that.

 

[wyo]

Thank you, sir! Will do.

 

[wyo]

Would these work?

Capacitors

Resistors

 

[Xian Xi]

Would these work?

Capacitors

Resistors

They're both fine. Personally I use 470uf@10v caps since they are slimmer and fit better.

 

[wyo]

Good to know, thanks!

EDIT: Just waiting on parts...

 

[wyo]

OK, I got the parts and opened up the system. Which resistors and capacitors need to be replaced? Here's what I see:

Also, I noticed two possibly broken solder points on the back of the PCB. Do these need fixing?

I'd really appreciate some help here before I screw something up.

 

[wyo]

Decided to give it a shot. I replaced the caps and resistors circled and resoldered the pins in the other pic. Worked great! The picture curl is gone. Overall improvement is minor but it was worth it just for that. Thanks again to Xian Xi.

 

[Xian Xi]

Good to hear. The brown shield thing is just soldered to 2 ground points to hold it down. If you plan to keep it on just solder them back down.

 

[wyo]

Done, thanks! I also performed this mod on my other AES without issue. It was definitely easier the second time around. I clipped the capacitor legs to an equal length and bent them to line up with the holes on the PCB.

 

[hank]

Hey sorry guys, I don't have privileges to add to create my own thread. I've been tearing my hair out over this video issue. I've got the bottom half of most sprites displaying twice, and the top half missing, as documented in my video. http://www.youtube.com/watch?v=rJpqxRgXM3U

-I've cleaned everything with isoprop, and the cartridge slot is spotless.
-I've tried different carts
-The video cable works fine on a PCE & MD1, and nothing changes when you jiggle it.
-I've tried 2 TVs.
-Console is very clean, checked traces with a magnifying glass, both sides.

Is it a bad Ram chip? or a bad processor. assistance GREATLY appreciated.

 

[hank]

NB# Using a MD 1 power supply.

 

[Xian Xi]

Hey sorry guys, I don't have privileges to add to create my own thread. I've been tearing my hair out over this video issue. I've got the bottom half of most sprites displaying twice, and the top half missing, as documented in my video. http://www.youtube.com/watch?v=rJpqxRgXM3U

-I've cleaned everything with isoprop, and the cartridge slot is spotless.
-I've tried different carts
-The video cable works fine on a PCE & MD1, and nothing changes when you jiggle it.
-I've tried 2 TVs.
-Console is very clean, checked traces with a magnifying glass, both sides.

Is it a bad Ram chip? or a bad processor. assistance GREATLY appreciated.

It's an addressing issue. Is this the only game that does this?

 

[hank]

In the video i try fatal fury special, then samurai shodown 2. They are boxed and immaculately clean. they both do it, and every time it happens, it happens the same amount.

Thanks A LOT.

 

[wyo]

In the video i try fatal fury special, then samurai shodown 2. They are boxed and immaculately clean. they both do it, and every time it happens, it happens the same amount.

Thanks A LOT.

Sarcasm? LOL

Your problem may require RAM replacement to fix.

 

[hank]

No, not sarcasm at all. This is a really quick reply to a fairly nebulous issue. There's no way to eliminate that the video processors are addressing incorrectly right? The bios check is fine. Would i swap out all the ram chips? or are there ones that are more fragile than others?

 

[wyo]

No, not sarcasm at all. This is a really quick reply to a fairly nebulous issue. There's no way to eliminate that the video processors are addressing incorrectly right? The bios check is fine. Would i swap out all the ram chips? or are there ones that are more fragile than others?

I'm sorry, your problem is well beyond my skill level.

 

[wyo]

Tonight I finally finished cleaning a MV4F I had laying around. To my surprise it seems to work fine. The only thing is when I hooked it up to my Big Red it too has a curl at the top of the screen. The difference is it's constant rather than affected by flashes or bright colors. My MV4 does not have this problem. OTOH, the sound is crystal clear on the MV4F whereas the MV4 has some distortion. It'd be nice to have one of 'em operating at 100%. Is this an easy fix like on the 1st gen AES?

Here is a pic of the top of the cross hatch screen:

 

[Xian Xi]

When was the last time you adjusted the hold pots?

 

[wyo]

When was the last time you adjusted the hold pots?

Thanks for the tip. Adjusting horizontal hold fixed it. The pot was kinda tucked away - didn't even know it was there until now

It'd be nice if all the controls were on the remote board that you can access from in front of the screen.

 

[wyo]

Update: I am having the same issue on my 20L5 with my AES with the replaced caps. Is there a horizontal hold option in one of the PVM menus?

The picture curls to the right like the MV4 and is not jerky.

 

[wyo]

Update: I am having the same issue on my 20L5 with my AES with the replaced caps. Is there a horizontal hold option in one of the PVM menus?

The picture curls to the right like the MV4 and is not jerky.

Adding a sync stripper to my Omega completely resolved sync issues with the 20L5. The AES issue, however, remains.

 

[skate323k137]

Look for H FREQUENCY and PHASE in the PVM service menu (If I remember right, that's what they're called on the 20M4U. I don't own an L5 to verify).

They both can shift the picture left/right but one of the two can result in h hold type issues if it's adjusted too far one way or the other. I'm not certain that's your issue but it's definitely worth checking.

 

[wyo]

Look for H FREQUENCY and PHASE in the PVM service menu (If I remember right, that's what they're called on the 20M4U. I don't own an L5 to verify).

They both can shift the picture left/right but one of the two can result in h hold type issues if it's adjusted too far one way or the other. I'm not certain that's your issue but it's definitely worth checking.

Thanks for the suggestions. I went back into the service menu and tried various adjustments in the Deflection submenus Focus and Raster H. Couldn't find any frequency adjustments and H DF Phase didn't do anything. There are Phase + and - buttons by the screen but it doesn't do anything when I press them. Here is a underscanned pic so you can see what I'm dealing with:

 

[skate323k137]

Yeah I know exactly what it looks like, my monitors do that if I get the phase or h freq adjustments too far off. I wish I were more familiar with the 20L5, sorry.