jeff412
New member
Awesome. I'll give that a shot tonight.
Jeff
Jeff
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Please post all monitor technical topics in the Technical - Videogames - Monitors section, not in the General Help section.
Space Invaders Multigame "Bit: Failed"
- Thread starter jeff412
- Start date
HudsonArcade
Well-known member
Or if you've got an earlier boardset it actually has the MB14241 chip instead of the daughterboard....
Did they use the MB14241 on Space Invaders daughter boards? I've never seen one using it (not that that means anything.....I've only seen the 25S10's used. I've seen the service bulletin referencing the satallite board/74151's). Is it on a satallite board in place of the 25S10's?..or a differently designed daughter board?
IIRC, I've seen a few Space Invaders Deluxe daughter boards using the MB14241.
Edward
shawzie
New member
Sorry to drag up such an old post. I have the very same problem with the horizontal lines, also added the braze kit (No change in issue) and see the same bit fail. How did you fix it? Did you replace the MB14241?
Shawzie
Shawzie
Try cleaning the edge connector of the daughterboard, make sure theres no bent pins on it and clean the legs of the MB chip if they have any crud on em.
shawzie
New member
Thanks for the quick reply, I've cleaned the daughter boards edge connector twice, once again today, also switched the ROM's for the Braze kit today. I also cleaned and re-flowed all the connections on the MB14241 on both sides of the board but that didn't help either. The only thing I can think is that the MB14241 may need replacing unless there is something else I could check. One thing I didn't think of is if the connections on the edge connector both sides are independent or mirrored on each side, any idea? maybe I've got I bad pin like you said as I was only checking one side.
shawzie
New member
Sorry, when you said clean the edge connector did you mean the solder fingers on the daughter board or the connector itself on the main board where they join? I cleaned the fingers on the daughter board only. What do you use to clean inside the physical connector pins?
Thanks
Shawzie
Thanks
Shawzie
I usually cut a piece of cardboard off a shoebox flap and put some 90% alcohol on it.
I replied in (several) of your other threads, but keep in mind that the MB chip is not the only part in the bit shifter circuit, so while its possible its bad, its not the only thing that can cause what you're seeing.
Do you have a logic probe and know how to use it?
I replied in (several) of your other threads, but keep in mind that the MB chip is not the only part in the bit shifter circuit, so while its possible its bad, its not the only thing that can cause what you're seeing.
Do you have a logic probe and know how to use it?
shawzie
New member
Orion3311, I appreciate all the advice you have given me. I don't have a logic probe and its been a while since I've used one. I'm planning to pick one up soon if not today if the weather gets better. I went through the board schematics last night and checked out connections from the MB with a multimeter, which looked good, all the controls connected to the MB work, all the audio connected to the MB is working. So I'm going to pull the boards out again and go over the 72pin connector with a fine tooth comb.
Thanks
Shawzie
Thanks
Shawzie
shawzie
New member
I've ordered a logic probe which should be here by next Monday (sooner fingers crossed) after going through the schematics for a while I'm guessing there is a problem on Data Line 5 on the logic / Sound board. Since the all the audio is working the only thing that I can see that could be the problem is an O-B monitor line out which when tracing back goes through a transistor to 74174 and onto D5 which connects to MB14241 and the D5 through the edge connector to the main board. Im wondering if pin 15 on the 74124 is stuck high or maybe another part connected to this line. I'm not going to switch out any parts until I test with the probe. Any idea what the O-B Monitor line is used for?
Not sure what you mean by OB monitor line but it sounds like youre describing the transistor circuit that tells the cocktail monitor to flip the screen for player 2. That shouldnt have anything to do with bit shfting, but youre on the right track to look for a stuck high pin on the MB chip.
shawzie
New member
Yeah, I'm not sure what this O-B Monitor line is doing (maybe its connecting to the relay but I'll need to see what connector pin 12 is connecting to elsewhere). Its labeled O-B Monitor on the schematic and I traced it back to the bit shitfter D5 line. I'll double check it again when I get home tonight as well as where pin 12 on the top connector (O-B Monitor out) is going. I'm very anxious to get this working 
and can't wait for that logic probe to arrive!
and can't wait for that logic probe to arrive!
Whats the part # of the schematic you're looking at?
I can def tel you pins 12 and 13 sounds like the monitor flipping circuit.
I can def tel you pins 12 and 13 sounds like the monitor flipping circuit.
shawzie
New member
The part # of the schematic that I am looking at is A082-90700-A000
I got the pin out information from http://www.brentradio.com/SpaceInvaders.htm
I got the pin out information from http://www.brentradio.com/SpaceInvaders.htm
Last edited:
shawzie
New member
Update: So today I started debugging again:
1: I done a Bob Roberts cap kit on the power supply.
2: Adjusted +5, -5 and 12 to be spot on.
3: I then checked the voltages at the edge connector. All were good.
4: Checked the connections from the control panels to the board connectors. All good.
5: Checked the 2 Coin Slot Pins, 1 was high and 1 was low, however the cocktail only has 1 coin slot and the previous owner removed the slot mech so I'm not sure what I should be getting on these.
6: Coin meter pin high. I assume this is normal.
7: Used a logic probe on the bit shifter. D0 - D7 all pulsing. Reset line on the bit shifter was high (I assume this is normal)
8: Used the logic probe on all the RAM Pin7s. Data out all pulsing.
Still got the bit error on the test screen and lines through the invaders. Any suggestions on what to test for next?
1: I done a Bob Roberts cap kit on the power supply.
2: Adjusted +5, -5 and 12 to be spot on.
3: I then checked the voltages at the edge connector. All were good.
4: Checked the connections from the control panels to the board connectors. All good.
5: Checked the 2 Coin Slot Pins, 1 was high and 1 was low, however the cocktail only has 1 coin slot and the previous owner removed the slot mech so I'm not sure what I should be getting on these.
6: Coin meter pin high. I assume this is normal.
7: Used a logic probe on the bit shifter. D0 - D7 all pulsing. Reset line on the bit shifter was high (I assume this is normal)
8: Used the logic probe on all the RAM Pin7s. Data out all pulsing.
Still got the bit error on the test screen and lines through the invaders. Any suggestions on what to test for next?
You say d0-7 is pulsing but did you check the output as well? I believe the outputs are labeled mx0-7 or something like that. Thats where the problem might be. It may even be another part pulling a bit down or up so it may not even be the bit shifter.
Bit Fail Error - Fixed
I just wanted to post to thank those that offered advice and suggestions in this thread, as it helped me get my Space Invaders Deluxe fixed.
I bought a Midway SI Deluxe in a cocktail cabinet from a guy about a month ago for $50. He said it wasn't working- the monitor had 'gone out' and the power cord had been frayed, so he cut it off so that his kids wouldn't try plugging it in and get fried.
After I put a new cord on, I plugged it in and the control panel lights and fan came on. I could also see neck glow on the monitor. After googling around a bit, I took the boards out, cleaned all of the edge connectors and pressed down on socketed chips to hopefully reseat them. That worked, and the machine seemed to be working.
The only problem was that about 25% of the time after I turned the machine on, there would be lines under all of the aliens which interfered with gameplay, and flying saucer sound effect would play constantly.
In the hopes that it might help someone else diagnose their problem, I'm attaching photos of the lines and a link to a video:
http://youtu.be/m2xCpQ6kkJg
I had ordered a Braze Technologies Space Invaders Multigame from arcadeshop.com, and I installed it in the hopes that it would help me figure out what the problem was. When it started up, the selftest showed 'Bit: Fail'. I had no idea what this meant, and I wasn't able to find any information on it on the Braze or Arcade Shop sites. However, I found this thread, which led me to checking the 4241 chip which apparently is a bit shifter. After I took it out of the socket, I found that the legs of the chip were pretty corroded. I cleaned them as well the edge connector again, and that seems to have solved my problems!
Thanks again for all of the information!
Rich
I just wanted to post to thank those that offered advice and suggestions in this thread, as it helped me get my Space Invaders Deluxe fixed.
I bought a Midway SI Deluxe in a cocktail cabinet from a guy about a month ago for $50. He said it wasn't working- the monitor had 'gone out' and the power cord had been frayed, so he cut it off so that his kids wouldn't try plugging it in and get fried.
After I put a new cord on, I plugged it in and the control panel lights and fan came on. I could also see neck glow on the monitor. After googling around a bit, I took the boards out, cleaned all of the edge connectors and pressed down on socketed chips to hopefully reseat them. That worked, and the machine seemed to be working.
The only problem was that about 25% of the time after I turned the machine on, there would be lines under all of the aliens which interfered with gameplay, and flying saucer sound effect would play constantly.
In the hopes that it might help someone else diagnose their problem, I'm attaching photos of the lines and a link to a video:
http://youtu.be/m2xCpQ6kkJg
I had ordered a Braze Technologies Space Invaders Multigame from arcadeshop.com, and I installed it in the hopes that it would help me figure out what the problem was. When it started up, the selftest showed 'Bit: Fail'. I had no idea what this meant, and I wasn't able to find any information on it on the Braze or Arcade Shop sites. However, I found this thread, which led me to checking the 4241 chip which apparently is a bit shifter. After I took it out of the socket, I found that the legs of the chip were pretty corroded. I cleaned them as well the edge connector again, and that seems to have solved my problems!
Thanks again for all of the information!
Rich
Attachments
Me too
OK.. Had this same problem. BIT failed in test. I don't have the daughter card. My MB
chip was socketed to the board. I cleaned the pcb edge connector with a fiberglass pen.
Also, I reflowed solder for each pin of the MB and no more issues.
OK.. Had this same problem. BIT failed in test. I don't have the daughter card. My MB
chip was socketed to the board. I cleaned the pcb edge connector with a fiberglass pen.
Also, I reflowed solder for each pin of the MB and no more issues.
Glad to see this working. My recently picked up SI will be a winter project, looking forward to playing it and cranking up for the "thump"ing.
troubydoobydoo
Member
I have the same problem with my game...Bit Error.
So thank you to everyone here who posted!
On this comment:
"which led me to checking the 4241 chip which apparently is a bit shifter."
How was this found to be a bit shifter and are there anymore I should know about?
I will pull my boardset out of the game and go clean all the connectors and check this chip as my next step and hope this fixes the problem. It might, as I get some inconsistent behavior.
Thanks again!
So thank you to everyone here who posted!
On this comment:
"which led me to checking the 4241 chip which apparently is a bit shifter."
How was this found to be a bit shifter and are there anymore I should know about?
I will pull my boardset out of the game and go clean all the connectors and check this chip as my next step and hope this fixes the problem. It might, as I get some inconsistent behavior.
Thanks again!
