So I get this Space Invaders Power Supply Rebuild Kit from Bob Roberts...

Tighe

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So I get this Space Invaders Power Supply Rebuild Kit from Bob Roberts...

And the two big caps are not axial! Do I just use jumper wires or is there another hole for a non axial cap. Also the printing on the two big caps is almost impossible to read, so I hope I put the right ones in the right spots! At least I know the polarity because the board it pretty simple.

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Ugh, the big blue cap is 20000 uf 16v, and the replacement is 22000 uf 25v! I know that the voltage doesn't matter only that it be the same or higher, but I sure up the higher capacitance is OK.
 
Its all good, just filter caps and won't hurt a thing. If I happen to go to the garage later tonight I can snap a couple pics of one I rebuilt, but its really not that hard.
 
Its all good, just filter caps and won't hurt a thing. If I happen to go to the garage later tonight I can snap a couple pics of one I rebuilt, but its really not that hard.

It's done, didn't fix the game though. :D

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If you still have the boardset plugged in, unplug the mainboard (connector in the middle) and see if you can clip lead a coin door lightbulb or something to the 5v and test again. (can even be a 12v light bulb you just want some kinda load on it).

Double-chk the schematic (located near the back of any SI manual, SI or dlx both the same) for this stuff as its been a while since I worked on those, but I believe the 5v comes from the 2n3055. Check each pin (including the metal housing) to see if its getting anything, I believe 9-12v. If so pull the 2n3055 and test to see if its any good (see bottom). If not, I think Radio Shack actually carries those.

If its not getting any voltage at all, check for bad diodes near the plug, or cold solder points on the plug itself. Those diodes will tend to test open but still be good (easier to test for voltages).

If the 2n3055 IS getting a feed, and it seems like it tests good, it could be the LM305 thats bad, and they're not readily available (at least not from a mouser or digikey - Riptor may have em)

Testing the 2n3055 - remove it, put your DMM on diode test, and go across each leg to a different leg. If you get no reading, reverse the leads, you should read "something" at least one direction from each leg to at least one other leg. If any one leg gets no reading to anything else in either direction, chances are its open/bad.
 
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That's pretty much exactly how Jeff F showed me how to replace the big cap on old williams power supplies pretty cool IMO.

Sucks you haven't gotten it to power up yet, i'd like to get some game time in next time i'm over.
 
I used Bob's kit and got mine running. Used a little jumper wiring.Voltages were fine at the test points..but not at the pcb. Had to reflow the connector on the power board and the game started right up.
 
If you still have the boardset plugged in, unplug the mainboard (connector in the middle) and see if you can clip lead a coin door lightbulb or something to the 5v and test again. (can even be a 12v light bulb you just want some kinda load on it).

Double-chk the schematic (located near the back of any SI manual, SI or dlx both the same) for this stuff as its been a while since I worked on those, but I believe the 5v comes from the 2n3055. Check each pin (including the metal housing) to see if its getting anything, I believe 9-12v. If so pull the 2n3055 and test to see if its any good (see bottom). If not, I think Radio Shack actually carries those.

If its not getting any voltage at all, check for bad diodes near the plug, or cold solder points on the plug itself. Those diodes will tend to test open but still be good (easier to test for voltages).

If the 2n3055 IS getting a feed, and it seems like it tests good, it could be the LM305 thats bad, and they're not readily available (at least not from a mouser or digikey - Riptor may have em)

Testing the 2n3055 - remove it, put your DMM on diode test, and go across each leg to a different leg. If you get no reading, reverse the leads, you should read "something" at least one direction from each leg to at least one other leg. If any one leg gets no reading to anything else in either direction, chances are its open/bad.

Couldn't it be the voltage regulators too? Looks like the 7812C was replaced -- and the person did a real bad job at it.

Well I left this open and forgot to post it...

I went to Radio Shack and was able to get a 2n3055 and a 7812C. They didn't have the 7602. I installed them in the board but there was no change. There is a thin plastic film between the regulators and the 2n3055 I left those in I assume they are there for insulation. There was no heat sink compond on the 2n3055 and only the tiniest bit on the 7812C, and it was only on the heat sink side of the plastic film.

Also I tested +5v with the SI boardset unplugged and a coin door bulb connected to the +5v test point. I still didn't get any voltage on the +5v with it disconnected. I disconnected all the connectors on the SI board, I don't know if that was the right thing to do.

I did a diode test using a 3v lithium battery for voltage. The red highlighted diodes would let ~1v reverse voltage, the magenta highlighted diodes would let ~2v reverse voltage, and the yellow highlighted diodes would let 3v reverse voltage.

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Noon bump, Please look at last post above. :D

Edit: Oh, and what is that 8 legged metal capped device near the +5v adjust pot?

Edit #2: I found this it should be somewhat helpful:

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Bob's got the LM305 for $4. On your power supply....It's in the 5vdc circuit, used for voltage regulation.

Edward
 
Bob's got the LM305 for $4. On your power supply....It's in the 5vdc circuit, used for voltage regulation.

Edward

Great! That is lots cheaper. I figure that is what I have to replace since I did pretty much everything else on that board that would go bad.

What about the diodes? Did you see what I did?
 
What about the diodes? Did you see what I did?

Yeah, I saw that....do you not have a diode setting on your meter?

The diodes in magents are for the audio voltage. If you've got 12-18 volts DC across the 1000uf cap, they're good. The ones in yellow are part of the reset circuit. If your reset circuit checked out (par the Elektron Forge instructions), they're good. The smaller ones in red are part of the 12VDC and -5VDC supplies. If those voltages checked out, they're good. The larger ones in red are part of the 5VDC supply. I doubt they're an issue. Measure voltage across the 20000uf cap. If you've got 8-14 volts DC, they're good.

The only thing left in the 5VDC line is the LM305 and the 2N2905.

Edward
 
Yeah, I saw that....do you not have a diode setting on your meter?

The diodes in magents are for the audio voltage. If you've got 12-18 volts DC across the 1000uf cap, they're good. The ones in yellow are part of the reset circuit. If your reset circuit checked out (par the Elektron Forge instructions), they're good. The smaller ones in red are part of the 12VDC and -5VDC supplies. If those voltages checked out, they're good. The larger ones in red are part of the 5VDC supply. I doubt they're an issue. Measure voltage across the 20000uf cap. If you've got 8-14 volts DC, they're good.

The only thing left in the 5VDC line is the LM305 and the 2N2905.

Edward

I have a diode/continuity setting but I don't get tone on those diodes. It works for baby diodes and leds... ...that is why I used 3v.

I am just going to order those parts plus the +5v pot. I will check it first.
 
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