RGB-modded IFU-30 sync issue (periodic flicker/shaking)

[Mogwai]

I realize I'm probably committing cardinal sin by asking for help in my first post without a proper intro (short form: lifelong gamer, used to drool over the TG16/Express through the Toys R Us display case, Rondo of Blood is my favorite game, etc). I'm a bit desperate for help and have been lurking heavily.

I purchased this white PCE/CD-Rom2 (w/ RGB mod on the IFU) recently http://www.ebay.com/itm/NEC-PC-Engine-INTERFACE-UNIT-RGB-Output-Excellent-Tested-Japan-/272686642500

It's connected with the included JP-21 RGB cable & AC adapter (9v 1.3a) to a XRGB-Mini, using a TED (not sure if that makes any difference). It works perfectly, except for a horizontal flickering & occasional vertical screen shake that pops up every 10-15 seconds (this varies wildly - sometimes it runs smoothly for longer, sometimes it's every few seconds). It's annoying enough for me to resort to playing via composite. Which is a shame given how gorgeous Soldier Blade and Rondo of Blood look over RGB.

I've tried messing with all of the XRGB sync settings to no avail. Oddly, the stability is much better if I have the composite cable plugged into the system (unplugged on the other end) while using RGB. With the composite unplugged, the stability nosedives to being unplayable. I have no idea what this could indicate. Grounding issue? Shielding/interference? Uneven power?

Does anyone know if this is an obvious indicator or red flag for a specific issue? Full disclosure: I am a newbie when it comes to dealing with electrical/mechanical parts. I'm learning, but I'd rather not crack open the unit unless I absolutely have to (for fear of accidentally breaking something).

Would greatly appreciate if anyone can point me in the right direction or give me a lead on this. Hopefully I can pay it forward down the line and contribute here.

[Keith Courage]

From most users I've heard just turning up the Sync settings on the framemeister fixes that.

IF not do you know how the RGB port is wired up? Is it using composite video for the sync signal or true c-sync.

Using true C-sync can be problematic with a IFU docking since running a wire to the place most people install their RGB port can get interference from the CD drive. 

Your issue might even be caused by a crappy AC adapter. Is yours original?

[Mogwai]

Thanks for the response & info. I tried every possible sync setting. Turning it from "auto" to "off" and setting the level to 10 was the most stable, but it still has the flickering issue.

I don't know how the RGB port is wired up, unfortunately. I will probably try to open it and see if I can figure that out.

I tried removing the CD unit - no difference there. Dunno if it matters, but it's sitting close to several other consoles.

AC adapter doesn't look to be original - took a pic of it and attached that. Original part number should be "AD-IF30" with 9V 1.5a, but I've read that this type of adapter should work. I'll try to track down an original to test it.

Attached a picture of the inside of the RGB cable. To my untrained eye, those wires seem like they shouldn't be exposed like that. Anyone know if this is normal?

(last picture is blurry/terrible but that's a severe example of the flickering on the TED menu screen)







last thing I noticed: there's a very audible hum/buzz that comes through the RGB cable even when the unit is powered off, which gets louder when the CD unit is removed

[Keith Courage]

That is how most Scart cables are made. So no worries there.

However, I wonder if you maybe have a generic scart cable. I recently had someone send me a cable with their system I am working on for them just to make sure their cable was good at the same time. Turns out his cable would produce a slightly blurry image compared to the scart cables I typically use. The slightly blurry picture almost looked like the ground was not wired correctly but I opened up the cable and all looked good. So it must have just been bad wiring in the cable itself. Maybe you should try another scart cable.