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Hi all, just joined today as I have got my first Dragon! I have never used one before so am slightly lost but learning quick!

This is a Dragon32 that I have connected using the coaxial cable to a CRT TV, the picture is pretty poor and does not have any sound, anyone have any ideas what I should be checking to try and resolve, the poor picture I can live with but the lack of sound is more what I am trying to fix.

Also, whenever I play a game from cartridge, the controls always seems to stick to bottom right diagonal. So my character in the game automatically walks bottom right whatever I do, this happens with any of the 3 cartridges I have.

I have seen a diagnostic ROM file but wondered is there anything like this I can load up from a converted .cas file to test the hardware?

Hope you Dragon masters can help a newbie out!

The poor picture through the coaxial cable is absolutely normal.

Also, depending on your motherboard version, you can have a patch for better video quality or not.

I'd just buy or build a monitor cable to output composite video to the TV which will improve the video quality.

The sound issue may come through a damaged PIA chip or a damaged modulator. If it's the modulator, you can get sound from the monitor port so maybe buying or building the monitor cable would be a good idea,

Which game cartridges do you have? Do you have any tape games or a tape cable (which you can use to load wav files directly into your Dragon)? And, can you take a picture of the circuit boards inside your Dragon?

Cheers,
Rob

Thanks for taking the time to reply

I managed to fix the in game issues, once a joystick was plugged in all worked well. I built an audio probe and confirmed that sound was being output on pin 10 of IC20, I then traced the signal all the way to the modulator and all worked well.

I tried the Dragon on a different TV and I can occasionally here some audio coming out, I don't have the remote for the TV so can't do any fine tuning but I assume it is a tuning issue. Unless there are any components known to fail inside the modulator that I should check?

Also noticed something else, sometimes the cartridge slot can be unreliable. I have to reseat it a couple of times before it will work.

Is this normal?

I still think that getting composite video and audio from the monitor socket is the way to go.

Regarding the cartridge slot, I’d try to clean it with air or contact cleaner. Also, clean the cartridges’ contacts with contact cleaner and cotton buds.

Pencil eraser on the cartridge also works wonders.

Indeed!

But remember to clean it with isopropyl alcohol or contact cleaner afterwards to wash away any remaining eraser.

@goobler I bought my composite video lead from Retro Computer Shack.

http://www.ebay.co.uk/itm/Dragon-32-64- ... 3cc787af8c