Issue: Colecovision loads BIOS screen but won't play games

[Issue: Colecovision loads BIOS screen but won't play games]

2 hours ago, ChildOfCv said:

The confusing part is that if the cartridge is not responding at all, or responds with the wrong signature, you should still get the "Please insert cartridge before turning on the system" message.  In this case, the cartridge must be actively interfering with the system, which means the ROM chip(s) think they are being accessed even if they are not.  I have to wonder if U5 is constantly outputting an active select on one of the cartridge lines.

It definitely recognizes that a cartridge has been inserted, because it loads a black screen every time. Take it out and the BIOS screen comes right back. Something I didn't think to do was to try to start a game even though the screen is black, like maybe it has music but no video. Regarding your comment, how could I determine if "U5 is constantly outputting an active select on one of the cartridge lines?"

 

Thank you for the suggestions so far. I will try them. I already tried cleaning the cartridge slot, but I only used canned air to blast it out. I'll try alcohol next.

[Issue: Colecovision loads BIOS screen but won't play games]

So my wife just acquired her childhood ColecoVision, and it's in really nice shape with the steering wheel, the super action controllers, tons of carts with overlays, you name it. When I turn it on, the screen displaying COLECOVISION loads just fine and is crystal clear with a modern A/V cable. However, any game I put into the cartridge slot just loads a black screen.

 

I know the games are good... I have another working Colecovision and I tested them in that machine. So my question for folks more skilled than myself is where do you start in diagnosing and fixing an issue like this? Can the cartridge slot go bad while everything else remains functional?

 

Most the tutorials I've seen for black screens just show that the system doesn't power on at all, but that is not the case here. I am a total amateur when it comes to these things... all I've ever done is replace capacitors in a Sega Master System. Any advice would be appreciated. If this issue is discussed elsewhere, I apologize for overlooking it.

[Yurkie's ColecoVision Mods RGB, VGA and HDMI May 2018]

I've sent a PM about some problems I'm having. Probably will require your services.

[Harmony Cart 7800]

Any news on the Harmony Concerto?

[sd cartridge for 7800?]

So, my wife is going to get me a Harmony cart for Father's Day this year, but before I spend the cash, anyone have any insight whether the Concerto has inched any closer to a release date? I'd rather buy a Concerto, especially if it will support 2600 ROMs as well.

I'm wondering the same thing. Came here to buy the Harmony, but then started reading about Concerto. Guess I'll wait, but for how long?