Sega Master System colors are off

[Red Hedgehog]

I recently acquired an SMS, never having really seen one before, and was surprised that the colors seemed so ugly. Everything seemed to have a yellow-ish tint. I then compared with an emulator and determined that my Master System's colors are seriously messed up.

The most noticable thing is that nothing is white. Things that should be white instead have a kind of yellow-greenish color. In fact, just about every color seems washed in a sort of yellow. In the first level of Hang On, the ground and moutains look decidely yellow instead of green and the sky has definite yellow in it. In Time Soldiers, I didn't even realize that the ground on the Stone Age level was supposed to be brown. It was much more green.

I have tried running through the RF cable (a NES one I had that worked fine for my Genesis) and the AV cable and the colors have the same problem (though they look slightly better through RF). I could try a different AV cable, or plugging it into a different input on my TV, but I'm pretty sure the problem is with the master unit itself.

In fact, occasionally the colors will undergo a shift and look normal. I've just left Hang On on in attract mode for about 15 minutes and now the colors look much more like they should (still not perfect, but I am running through RF currently, so that might be the issue).

Any help for how to get accurate colors each time would be appreciated.

[FABombjoy]

Some possibilities:

-Defective CXA1145 RGB video encoder chip
Weird stuff can happen when chips like this start to go out

-Defective VDP
See previous statement.

-Defective input to CXA1145
Can you see red, green, and blue? If blue disappeared, white would become green.

[omnedon]

Check the solder joints on the Sony encoder chip. I've seen them have loose joints more than once.

[Red Hedgehog]

Check the solder joints on the Sony encoder chip. I've seen them have loose joints more than once.

Yeah, I was figuring I would have to open it up and was posting here to get some pointers before doing so. Is there a diagram or picture I can look at to know what I should be looking for?

And if the solder joints are loose, I suppose that means I'll have to invest in a soldering iron and and some solder. Haven't done that since 12th grade physics...