N64/NES Weird Display

[Sharkspine]

Hello

I apologise if this isn't really the right place for this but as you all seem technically minded I thought I'd try.

I own a Sony Trinitron CRT. Plays SNES, Mega Drive, PS1, PS2, original Xbox, Saturn with no issues at all for many years.

My TV has one scart socket which accepts AV and RGB and so I switch between the two depending on the requirement.

It used to play my NES and N64 no issues too until I got them out of storage this year.

The NES displays a very dark image and the colours are strange. The clouds in Mario are Black for example. Almost like the colours are inverted.

The N64 is very dark too and on Mario 64 Marios skin is a dark brown.

I've tried different leads and power packs with both, same result.

I borrowed a cheap LCD off my neighbour, hooked both the N64 and the NES up and they are fine. Colours and brightness are all as you expect. I used the same consoles, leads, game carts.

So the issue is the TV. But that plays every other console nicely. I even hooked my BBC Micro and Amiga 500 up to it and they look lovely.

What could be causing the issue for those two consoles? Could there be a setting in the service menu or does it sound purely hardware?

Thanks again for reading and take care,

Ryan

 

[Sharkspine]

Thank you both for your responses. Much appreciated! I shall take a look and see what I can do. Damaged or dirty composite pins does seem a good hunch.

Just for clarity: N64 unmodded. Computers were connected via RGB.

 

[Sharkspine]

This morning I connected the N64 via my TV's front yellow phono jack and the issue remained. No difference

I also connected both the N64 and the NES via RF and the issue was there via that method.

So the fault doesnt appear to be isolated to the scart socket if at all.

So definitely not consoles or cables. Definitely TV. But not the scart socket itself.

 

[Sharkspine]

@Sharkspine did you ever get to treat bottom of this?

Hello

Sorry for belated response. Have been busy tracking down a local repair person. Not easy.

Left it with a reputable gentleman at the weekend who phoned me this morning.

He has cleaned it up, resoldered some connections on the scart and generally gave her a good check up and has isolated the problem to the RGB 'CHIP' (I can't remember exactly what he said)

He said theres a specific part of the chip which has failed. Basically the non RGB signals are not being processed. He sent me a photograph of the chip and identified the part at the top which needs repairing or replacing. This is what is written on the chip:

SAA549BPS/ 014 (This is the part)
72700741
02 10P TEXT
PHILIPS 1994
INTEL 1980
bSS9744M1X

Does anybody know what that part is precisely? May help tracking it down?

He says if we can find it he can repair it.

He also suggested using a VCR as a passthrough/signal converter?

Thank you for any help!

 

[Sharkspine]

Yes. Been perusing it.

It's a BE-4A chassis. Model is KV21 3TU

I've found the part in the manual with the nearest name to that in the photograph and it appears to be a Semi-Conducter.