Joust Power Supply Question

bbeckwith

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Hey guys, I have a real quick question.

I'm attempting to figure out why my 12v fuse keeps blowing at F3. I have already capped the power supply PCB, got rid of the 2 old single wipe sockets where the LM723s go. My only question is which way do the LM723s face?

The notched side of the socket is printed on the PCB but originally the LM723s were facing the opposite of the notch....see my picture, you can see the screen printed PCB and the direction that the LM723s were originally seated, which doesn't seem right to me...

Thanks
 

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Hey guys, I have a real quick question.

I'm attempting to figure out why my 12v fuse keeps blowing at F3. I have already capped the power supply PCB, got rid of the 2 old single wipe sockets where the LM723s go. My only question is which way do the LM723s face?

The notched side of the socket is printed on the PCB but originally the LM723s were facing the opposite of the notch....see my picture, you can see the screen printed PCB and the direction that the LM723s were originally seated, which doesn't seem right to me...

Thanks

They were flipped. Square notch to notch. NOT circle. If that doesn't fix it then it's probably a bad BR2 or the 2N3055 on the heatsink. IC#1 handles that voltage (the one on the left in your pic).
 
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They were flipped. Square notch to notch. NOT circle. If that doesn't fix it then it's probably a bad 12v rectifier.


That's what I thought, thanks for confirming. I reflowed all of the header pins with new solder, and got the LM723s positioned correctly. All lights on the power supply turned on when I powered the game up, but after about 3 seconds the 12v went out and blew the F3 fuse.

Looks like I'm going to order that rectifier.

Thanks for the info
 
That's what I thought, thanks for confirming. I reflowed all of the header pins with new solder, and got the LM723s positioned correctly. All lights on the power supply turned on when I powered the game up, but after about 3 seconds the 12v went out and blew the F3 fuse.

Looks like I'm going to order that rectifier.

Thanks for the info

I edited my above post using the schematics. I lost my 12v a couple years back and it ended up being BR2, but I had already replaced the LM's and the 3055 using a renew kit, so you may want to just look for one of those and do it all...
 
I edited my above post using the schematics. I lost my 12v a couple years back and it ended up being BR2, but I had already replaced the LM's and the 3055 using a renew kit, so you may want to just look for one of those and do it all...

I've already replaced the 2N3055 so that narrows it down a bit.

Yea I just ordered all of the bridge rectifiers (BR1, BR2, BR3) from good old Bob Robert's, the big 14000uf, fuses, and the power adaptor so I can use the 4164 rams.
 
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Just an update. I replaced BR1, BR2, and the 1800uf cap, added new 4164 ram and Bob roberts adapter.

No more fuses are being blown so I got something right. I'm showing all 3 lights red on the power supply. However, the video is showing nothing but an orange screen, no sound, can't coin up, and the ROM board is not displaying any numbers...

Damn you Joust
 
The ribbon between boards would be my next step. Also I know the leds now light but is the voltage output correct? Could still be messed up if those LM's that were switched were damaged.
 
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Hey guys, I have a real quick question.

I'm attempting to figure out why my 12v fuse keeps blowing at F3. I have already capped the power supply PCB, got rid of the 2 old single wipe sockets where the LM723s go. My only question is which way do the LM723s face?

The notched side of the socket is printed on the PCB but originally the LM723s were facing the opposite of the notch....see my picture, you can see the screen printed PCB and the direction that the LM723s were originally seated, which doesn't seem right to me...

Thanks

RTFM -- The silk is correct.

You can also see in the schems that Pins 11 and 12 are tied together, and you can see those traces on the board.

With the chips in backwards, that would be 3 and 4 tied together, and the schems show that's wrong.
 
I'm going to get a small laundry list of parts to bulletproof this sucker lol.

- Ribbon cables
- Cap kit for the WG4900
- new sockets for the 4164s
- new display LED for the ROM board

I have already replaced the old LMs with new ones. I am receiving 12.34v and 4.75v on the CPU/Video board.

The ribbon between boards would be my next step. Also I know the leds now light but is the voltage output correct? Could still be messed up if those LM's that were switched were damaged.
 
In my experience 4.75 is too low for Joust, there are some resistors you can move to increase. Don't have the info on the exact ones right now, but it's easy enough to find online. This may be the problem. You can also get new headers and pins for the power board. That could reduce some of the voltage losses. I also doubt the # display is bad.
 
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I say this a lot, in the hopes that people finally listen.

the factory headers aren't good. you probably also noticed when you reflowed them that the solder doesn't even distribute right. at this juncture they're probably bent, very dirty (a hindrance on power flow), and not to mention they're inferior, round, and skinny. I replace all the headers on the power supply and power inputs on the MPU and rom boards. you will also have to change out the filter caps on the MPU and rom board, as they will swallow up +5. this can be anywhere from .30-.80V in my observations across about 10 games.

I don't know why you're replacing the seven-segment display on the rom board, but more power to you. a bad ribbon cable will prevent anything from appearing on that display, and more specifically, the game itself won't run.

I do the trace mod from scoresaves, you'll just lose more voltage across the Bob Roberts adapter. you'll additionally be up shit creek if you pull that board to diagnose another game and forget the adapter. it's 1 trace and 1 jumper wire and you'll never have to dick with adapters again.

and lastly, 2N3055 is for +5 output; the smaller bridge rectifier is for +12 I think. the giant axial cap is also for the +12 line, I don't think it has any bearing on regular operation, it's just for supplying a burst of +12 when you power the game off for the CMOS. (which is why these games and switchers don't play well and it corrupts the CMOS in some instances frequently)

if any of my information is incorrect at any point, you may provide corrections as necessary.
 
Thanks for the post. I appreciate you sharing your knowledge on the subject, as I obviously don't know anything about Williams games.

I will go ahead and order new header pins, and ribbon cables. The only reason I put the segment display on my list of parts was because I thought it had maybe gone out....

As for the Bob Roberts adapter, I will not be using this board to swap and test on other games, so I won't venture down shit creek. Bob includes a large sticker to put on the PCB as well so you can remember that it has 4164s in it.


I say this a lot, in the hopes that people finally listen.

the factory headers aren't good. you probably also noticed when you reflowed them that the solder doesn't even distribute right. at this juncture they're probably bent, very dirty (a hindrance on power flow), and not to mention they're inferior, round, and skinny. I replace all the headers on the power supply and power inputs on the MPU and rom boards. you will also have to change out the filter caps on the MPU and rom board, as they will swallow up +5. this can be anywhere from .30-.80V in my observations across about 10 games.

I don't know why you're replacing the seven-segment display on the rom board, but more power to you. a bad ribbon cable will prevent anything from appearing on that display, and more specifically, the game itself won't run.

I do the trace mod from scoresaves, you'll just lose more voltage across the Bob Roberts adapter. you'll additionally be up shit creek if you pull that board to diagnose another game and forget the adapter. it's 1 trace and 1 jumper wire and you'll never have to dick with adapters again.

and lastly, 2N3055 is for +5 output; the smaller bridge rectifier is for +12 I think. the giant axial cap is also for the +12 line, I don't think it has any bearing on regular operation, it's just for supplying a burst of +12 when you power the game off for the CMOS. (which is why these games and switchers don't play well and it corrupts the CMOS in some instances frequently)

if any of my information is incorrect at any point, you may provide corrections as necessary.
 
I say this a lot, in the hopes that people finally listen.

the factory headers aren't good. you probably also noticed when you reflowed them that the solder doesn't even distribute right. at this juncture they're probably bent, very dirty (a hindrance on power flow), and not to mention they're inferior, round, and skinny. I replace all the headers on the power supply and power inputs on the MPU and rom boards. you will also have to change out the filter caps on the MPU and rom board, as they will swallow up +5. this can be anywhere from .30-.80V in my observations across about 10 games.

I don't know why you're replacing the seven-segment display on the rom board, but more power to you. a bad ribbon cable will prevent anything from appearing on that display, and more specifically, the game itself won't run.

I do the trace mod from scoresaves, you'll just lose more voltage across the Bob Roberts adapter. you'll additionally be up shit creek if you pull that board to diagnose another game and forget the adapter. it's 1 trace and 1 jumper wire and you'll never have to dick with adapters again.

and lastly, 2N3055 is for +5 output; the smaller bridge rectifier is for +12 I think. the giant axial cap is also for the +12 line, I don't think it has any bearing on regular operation, it's just for supplying a burst of +12 when you power the game off for the CMOS. (which is why these games and switchers don't play well and it corrupts the CMOS in some instances frequently)

if any of my information is incorrect at any point, you may provide corrections as necessary.

Thanks for the info!
 
I'm capping my sound PCB right now and noticed the old cap had the positive side on the left, yet the PCB has the positive side screened on the right.... check out the picture, as I think the PCB was screened wrong? Can someone conform for me?

Thanks
 

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I'm capping my sound PCB right now and noticed the old cap had the positive side on the left, yet the PCB has the positive side screened on the right.... check out the picture, as I think the PCB was screened wrong? Can someone conform for me?

Thanks

Looks like you installed your replacement wrong. The indentation is the positive side.
 
Thanks guys.

I will get it swapped the other way. I guess this is the first time I've seen a cap that indicates the positive side instead of the negative side.

Thanks a ton!
 
Thanks guys.

I will get it swapped the other way. I guess this is the first time I've seen a cap that indicates the positive side instead of the negative side.

Thanks a ton!

yes your + should be to the outer edge of the pcb on the sound board. i have been building the ps and sound pcb kits and keep expanding the types including alot of pinball kits too.

BTW: i stock all the 20,000uf and lower axial caps in 105c for the williams kits i make and i have all the other parts in stock. i am starting to put pots in to make the 5v line adjustable in my kits and i do have the correct 18,000uf for the joust power supply which is what it originally had.
 
I say this a lot, in the hopes that people finally listen.

the factory headers aren't good. you probably also noticed when you reflowed them that the solder doesn't even distribute right. at this juncture they're probably bent, very dirty (a hindrance on power flow), and not to mention they're inferior, round, and skinny. I replace all the headers on the power supply and power inputs on the MPU and rom boards. you will also have to change out the filter caps on the MPU and rom board, as they will swallow up +5. this can be anywhere from .30-.80V in my observations across about 10 games.

I don't know why you're replacing the seven-segment display on the rom board, but more power to you. a bad ribbon cable will prevent anything from appearing on that display, and more specifically, the game itself won't run.

I do the trace mod from scoresaves, you'll just lose more voltage across the Bob Roberts adapter. you'll additionally be up shit creek if you pull that board to diagnose another game and forget the adapter. it's 1 trace and 1 jumper wire and you'll never have to dick with adapters again.

and lastly, 2N3055 is for +5 output; the smaller bridge rectifier is for +12 I think. the giant axial cap is also for the +12 line, I don't think it has any bearing on regular operation, it's just for supplying a burst of +12 when you power the game off for the CMOS. (which is why these games and switchers don't play well and it corrupts the CMOS in some instances frequently)

if any of my information is incorrect at any point, you may provide corrections as necessary.

The 2n3055 is for 12 v operation on williams supply, it directly feeds br2. It supplies +5 on an atari arII, but is stepped down on voltage. The +5 is handled by the 6057

You can increase +5 by removing r10 and staying in tolerance range, but I like to replace r26 with a pot to make it adjustable.
 
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