Buck Rogers monitor problem

[retroshaun]

I took a little time (finally) to look at my Buck Rogers today, finally taking the back off to adjust the monitor as I always thought it looked way too green.

 

After setting everything to a pretty much neutral setting (R, G, B, contract, brightness all centered) it looked better but something didnt seem right from my memory of the game. After firing up Mame I can see that theres simply no red in the picture at all.

 

If I blast the red adjustment up the monitor definately goes very red overall, but the parts that should be red (main title screen logo, engine thrusters, lights on the enemy ships etc) are black.

 

What could cause this? Is this a monitor or board issue? I even questioned if it could be a bootleg board, is this possible? I have no desire to mess with monitors too much so if thats the problem then I'll look at a replacement or even finding someone to repair it.

 

Thanks!

[Rybags]

Checking in MAME, that game has a Service/Self Test mode.

 

Press the Service button, let it verify the EPROMs. Then press it twice more. You get a bunch of vertical coloured bars.

Maybe you could run that in MAME and the real machine, then adjust your controls to get them looking alike.

[retroshaun]

Yeah I tried that. I can't even get it close. The first stripe in the test pattern is meant to be bright red and on my cab it displays black. When I boost the red on the monitor, that stripe and all the border etc go to a overall "overbright" red. Its as if the red areas arent even being sent a red signal, thats teh way it appears. Is this possible? Could there be a board or (more likely?) wiring fault causing there to be no red sent to the monitor?

[Cassidy Nolen]

You know the red gun works, thats good. I would guess, without even seeing the monitor, it could benefit from reflowing solder on the connector pins. Jiggle the input connector, should be something like a red,green,blue,black,white wire connector and use a mirror to see if all colors show up. Could still be that the connector isn't making good contact but I try this step before going further. If it gets better, just lift the chassis up (power OFF of course!) and reflow the solder to those pins. If not better, let us know what monitor it is and we can help you go from there. It could be a board issue but I would guess not. Might try cleaning the contacts on the PCB where the video harness plugs in. Not super familia with that gen. of Segas but theory is all the same; contact good, dirt bad

 

 

EDIT: Apparently Sega used EVERY monitor of that era in that machine (just looked in the manual over on klov.com). You could have one of several monitors, the 4600 being the most tempermental of the three you could have. Not a bad monitor, just more likely to develop bad connections, given that it is made up of several boards and not just one). If its the "toaster" style 4600 try reseating each of those boards on the chassis as well.

 

CN