Robotron collection of issues

JDGJr

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Robotron U/R with multiple issues

Just picked a U/R from a local seller who gave up on it - he said the boards had been serviced and the monitor was fine, probably a problem with the power supply. Ok, it was cheap and I'm trying to learn as well as have fun...

Got it home, plugged it in - got video, sound, and play! Aside from automatically moving right and not being able to go left, it seemed to play as i remembered.

Looking around and powering up/down, i see someone put in another PS (switching?) for the +5v and the LED1 does not light on the original board. And some wires are now soldered to the original PS board (connectors cut into pieces)

Checking the wiring of the movement joystick shows nothing abnormal, test screen has 'move right' on constantly. Disconnnecting the connector from the CP doesn't change this. Disconnecting 3P2/3 does not change it either.

A few times I have seen startup rom errors - mostly #12, but once #6, but after restart, everything plays as before.

And, the sound test repeatedly plays Sound Line 1, but none of the others - the test button on the sound board cycles through many different sounds.

So I plan to remove the new PS, and get the original board rebuilt. I think that can't help but improve the stability of rest of the system.

Anyone have suggestions on the joystick or sound issues?

thanks!
John
 
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Based on the symptoms, it sounds like the I/O card may be bad. You might also want to check the ground connections on the suspect joystick.

You can test this by pulling both connectors from the I/O card and going into the switch test. If the I/O card is OK, there should be no switches showing. If there are, it is probably the card or possibly the cable to the MPU board. Try carefully flexing the ribbon cable on the I.O card to see if the switches clear up. It is not uncommon for the ribbon cables to come loose and need to be recrimped.

If that doesn't work, I do repair Williams boards. I rebuild I/O cards for $15 + parts + return shipping. I also rebuild power supply boards for $20 + parts + return shipping.

Most of the time on I/O cards it is the 4049 chips that go bad, but sometimes it is the PIA (the big chip) and every so often it is one of the resistor packs (the flat orange parts) that go bad.

Rebuilding the power supply is generally a good idea because of the issues Williams games have with switching power supplies and losing setting and high scores. I won't go into details because it had been discussed at length in the forums. Just search for Williams and switching power supplies.

PM me and I can supply more information about getting your boards diagnosed and repaired.

ken
 
so you got it, huh? post some pics!! i wish i had the room and money to have picked that up. did they budge on price at all, or were they firm like the ad said?
 
so you got it, huh? post some pics!! i wish i had the room and money to have picked that up. did they budge on price at all, or were they firm like the ad said?

Yeah, called the guy yesterday - he insisted on 1stcome1stserved, so arrived an hour before he said it would start. No haggling - he pulled the machines into the back parking lot and would let you take it if you had the $$$. Dunno if it rained, don't think he'd really cared - this was just to get them out of his space. Did you notice several machines are now free (could haul away a working and parts Outrun at the same time) - not on my wishlist.

Standard machine, with a repro control overlay - and solid black sides :eek: - otherwise, he couldn't get it working consistently so sold if for cheap. Will give me something to do if Spring ever arrives.
 
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