Chinese Assembled Analogue IO/Component Video Color Issues

[fistofmana]

I'm new to Mister and wanted to relay some of the experience I've had regarding issues with component video. Like some others, my IO board came pre-assembled from China and I was immediately dissapointed with the component video output. It appeared to have a slight magenta hue that I wasn't able to properly correct for using my CRT's service menu (Toshiba 27A43). As far as I could tell (tested with one VGA lcd monitor), VGA appeared normal.

I tried different .ini settings but was able to verify that mine were correct. I re-flowed most points on the board with no change in the issue. After searching through many different forums, I came to the conclusion that it was most likely the resistor array combination. My board was using a 201/471 combination, which was wrong because the second resistor set should be as close to 2 times the first as possible. I read that some UK boards were using a 240/470 combination that appeared to work correctly so this is what I intended to aim for. I also found that 300/604 was popular.

I went ahead and ordered some 240's/300's/604's from Mouser just to have enough to try all of them. First, I simply replaced the existing 201's to create the combo 240/471 (from what I heard, the 471's are still 470 ohm). Maybe one of my joints was bad, or maybe there were issues with the 471's, but this combo did not provide a desireable effect. The magenta hue was gone (yay!), but in return, I got missing colors and some other distortion.

Next, I tried the 300/604 combo and this was the winner. The colors were accurate and no percievable distortion. However, it comes with it's own downside, the RGB output was noticeably weaker which I was easily able to correct with some contrast/brightness adjustments on my TV.

Sorry any technical errors that may be in this, I just wanted to piece this together for anyone else that may be experiencing this and not know how to proceed.

Moral of the story, if you buy one of the cheaply built IO boards and are getting color issues, check the resistor combination and if it's 201/471, you might want to look at getting a refund if you don't have the equipment to replace the resistor arrays.

[mineral55]

I got burned by retroscaler / bitfunx on aliexpress so I feel your pain and now I'm stuck with these useless cheaply made daughter boards that (I thought) are unsalvageable. I considered maybe saving the boards to repopulate them like you managed to do but I had a hard time imagining the PCBs are properly manufactured to spec so I changed my mind but it's impressive that you were able to.

Thankfully I have the proper boards now and I'm quite happy with my setup and I hope yours is holding up nicely

Screw these scammers as well as aliexpress that literally deleted my review detailing my frustrations. It seems they are getting good reviews from less scrupulous buyers that likely aren't using analog out so they can proudly display those on the page and maintain an appearance of respectability because valid reviews such as mine as quickly discarded.

They should be named and shamed IMO since they harm the MiSTer community and undermine its vision.

[carlo3do]

fistofmana can you please list the part # of the Resistor Networks, Arrays you got from Mouser?

Thank you in advance