Neo Geo CD Black Screen Problem

[cawley1]

Guys,
I have a Neo CD toploader I got off eBay non working, basically the issue is that there is no picture when you boot the system with either composite or RGB scart lead (from the 8 pin DIN) connected.

I can hear the Neo CD boot screen sound through both connectors, and my PAL TV even 'jumps' into NTSC mode, as with all my working NTSC consoles - it looks like it is picking up the sync, so why won't it display any other image?

I have taken it apart, and from a quick look, I can't see anything obvious. Is the fault likely to be with the main board, or a problem with the connector board where the power and video sockets are?

All help appreciated.
Cheers,
Paul

[l_oliveira]

Your TV is picking the sync signal but seems like there is no RGB at it's inputs. I'd say you have to check the A/V board (Around the CXA1645 chip) for faults.

[cawley1]

Hi,
Thanks for your reply, what is the best way to check the board, as I have physically looked it over, and there appear to be no visible problems.
I am not a great techie, but will I need to get out the multi-meter to check this thing?
I have another Neo CD, but that one is brand new, so I don't really want to take it apart if I can avoid it!
Cheers,
paul

[l_oliveira]

Well....  I don't have a Neo Geo CD to use as reference. What I can say is that you might want to check if the CXA1645 chip is receiving power (5volts).
I am almost sure that SYNC is supplied through another (direct) output from the motherboard but RGB is amplified through the CXA chip.

It having no power would result on the TV getting sync but no RGB thus giving you a black screen.

[Padoca85]

i have the same problem here, but no signal at all from the video, i tried all the outputs.
the previous owner said its used to play and one day he heard something pop and no vid anymore.
I open the system and looked several times but dont see any apparent defect

maybe something on the vid board has died, can i harnest the signal of the vid before it go to the vid board?