PCB Help: Volfied

[yagamikun]

My partner got me a Volfied board for my birthday a couple months back. The board was sold in 100% working condition, but of course it's not...and by the time my partner gave it to me it was well outside of Ebay's return window.

Anyway, I have absolutely no idea where/how to begin trouble shooting the issue.

The Issue:

• Generally, the game boots fine, displays all graphics and sounds correctly, and plays correctly.
• Issue 1: There's a large flicker that happens across the screen during playing every so often - it's just a split second but noticeable.
• Issue 2: After clearing a stage and the screen starts to do all the little explosions, the graphics and sound cut out completely to a black screen for about two seconds then pops back up just as the next round comes on the screen.
• These issues happen on a real cab (tested on a NAC and Dynamo) and on an Axun Supergun running via a RetroTink.
• Here's a video I found with the "flicker" glitch. I'll try to take a video later of the brief black screen glitch that happens after clearing a stage.

I'm not super great with soldering, but can do it in a pinch. I'll post to VAPS, but thought I'd see what you lot could help out with first.

 

[awbacon]

Sounds like a sync issue. Ive had a similar "issue" with my Invasion: The Abductors board....it just flickers / loses image ONLY during the end stage results screen where it tallies up the scores. The fact you lose the image DURING that effect / transition just reminds me of the Invasion "issue"...when in reality it's not exactly an issue...its a "weird sudden refresh rate feature"

I checked frame rates out and that one section just throws the refresh rate off JUST enough to flicker / drop image until it recovers.

No guarantees that's what it is but it is at least a direction to go

only other idea I could have is you have some barely failing but potentially bad ram. Something about just a FEW assets struggling to read/write to a specific memory address. Less likely but just an idea

 

[Neodogg]

I realize you sold this board but maybe you need a sync cleaner?
I have a couple of these from busta around:

FS Parts: - LM1881 Sync Cleaner PCB

I will be offering assembled LM1881 sync cleaners pcbs. These things are tiny at 19mm X 13mm x 3.5mm (0.75in X 0.50in X 0.15in). Small enough to fit easily into a Scart cable. These are all made using name brand parts ( Texas Instruments, Kemet and Panasonic) no cheapo Chinamart knockoffs. The...

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