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Title: Taito Space invader problem Post by: mammyrat on March 13, 2009, 10:17:08 PM I just obtained a nice Taito Space Invader Trimline (mini). It works great with one minor problem. When the game starts the man moves all the way to the right and will not return. Even if I unplug the control panel. What could be the problem?
Thanks. Title: Re: Taito Space invader problem Post by: jay on March 13, 2009, 10:40:57 PM The joystick is simply 2 switches. It sounds like one is stuck, but if the control panel is disconnected I would look for a short in the harness.
Title: Re: Taito Space invader problem Post by: mammyrat on March 15, 2009, 08:55:40 PM Thanks, I will check it out and post my findings.
Title: Re: Taito Space invader problem Post by: mammyrat on March 21, 2009, 10:01:38 PM I pulled the wire from the PCB connector and the base still goes to the right.
I assume this means something on the boards. I pulled the boards, didn't notice anything obvious. I cleaned them with a nylon bristle brush and compressed air, cleaned all the connections for the harnesses and jumpers and it still does the same thing. Any ideas? Thanks Title: Re: Taito Space invader problem Post by: li_gangyi on March 22, 2009, 12:07:48 AM I would start by probing around the 74153s (multiplexer) and 7414s (inverter), that come after the inputs. See if on any of them the output is stuck for some reason.
A logic probe / oscilloscope will be real good for this, failing that, a DMM might work. Title: Re: Taito Space invader problem Post by: mammyrat on March 22, 2009, 12:57:08 AM Thanks, I'll get out my scope and see if I can figure something out this week. Is a logic probe a handy device to have even if I have a scope? If so , can you recommend a good one to get?
Thanks, Alfred Title: Re: Taito Space invader problem Post by: li_gangyi on March 22, 2009, 01:46:58 AM If you have a scope that'll be better than a logic probe usually, because now you can see the quality of the waveform and fast changing signals... I prefer my oscilloscope to a logic probe.
For a logic probe, anything that'll do tri-state (High, Low, and High-Z or no signal), is what you are looking for, some of the cheaper ones don't do the High-Z (no input, totally disconnected etc.) and show a false reading (usually high). Title: Re: Taito Space invader problem Post by: mammyrat on December 09, 2009, 01:23:53 AM Finally got around to working on the S.I. The I replaced 7414 coming off the right joystick switch and the game works great!
Thanks for the help. Title: Re: Taito Space invader problem Post by: channelmaniac on December 11, 2009, 01:40:28 AM Sweet!
Thanks for taking the time to let us know! RJ |