Omaha, NE
Plugging in with off by one -- shorted 5V to 12V and +HV to -HV. Looks like one of the HV regulators is blown. With a little luck, might get by with just replacing the one bad regulator.
(Topic ID: 52420)
Linked Games
F-14 Tomcat
Williams, 1987
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Quoted from practicalsteve:Is that what I blew in the third pic back in the beginning of this thread? With all the smoke, burning smell, and sparks I just cant see how I did not kill those displays.
That is one of the two HV regulators that is toasted. Not sure which as Jim doesn't have schematics posted for that board.
You threw a short directly across the two regulators - output of positive HV regulator to output of negative HV regulator. May have taken out both positive and negative regulators but only one shows physical damage. I think the regulators took the full bore and didn't send the short to the displays. I would replace both, for the cost of two regulators (less than $2 in parts) - it may be well worth replacing them two and trying it again but without the misaligned connection this time. Worst that can happen is it won't work...
Quoted from practicalsteve:I think i may repair the board first and see what happens, i need to place an order with GPE anyway for keys so might as well, hey is the person posting as G-P-E Ed from great plains? I guess i can't screw up the board more than it is already, the positive HV regulator is the toasted component in the third pic of the thread correct? Which is the negative HV regulator?
Yup, that's me.
Check your actual board for final part numbers in case they are different from the schematics!!! The schematics say the negative HV regulator (burned one) would be an LM337T and the positive HV regulator would be an LM317AHVT.
According to WPD011A schematics (if this matches yours) --
U1 is positive HV regulator
U4 is negative HV regulator
U6 is 12V regulator
With the way the board is designed - a rather radical failure of components is possible if the display is shorted. But, it still may be worth the $2 in parts and the possibility of this happening to determine if the display is bad. New displays, as you have found, cost a heck of a lot more.
Quoted from practicalsteve:Awesome I just checked and U4 is LM337, and U1 is LM317 (there were no letters after them, does that make a difference?) I will be placing an order later. Thanks so much, I always recommend GPE for anything electronic.
There probably is an "AHV" somewhere on the 317 somewhere. If not, I would be rather surprised.
The "T" suffix is implied and is often not marked. This simply means a TO-220 type package which is what is used on that board.
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