Joust power supply doesn't match the manuals online; also ticking sound from the CRT

[olePigeon]

Hello,

I was troubleshooting my Joust and was going to check the voltages, but my Joust doesn't match the only manuals I can find online. Not only is the power supply different, but so is the harness to the various boards (my Joust ROM board only has one 5v line, whereas the manual indicates two.) It's working fine, but I wanted to recap it anyway for preventative maintenance. Is there an alternate manual?

Also, there's a ticking noise coming from the CRT, almost like the sound of a watch. I'm assuming it's arching a tiny bit? I watched a CRT repair video on YouTube, but I wanted to confirm the safety of their tip before proceeding. The person said that putting a little silicone grease on the anode sucker will help create a better seal; I'm thinking that might help with the arching. I do have a CRT discharge tool, so I'm confident I can do this safely.

As a side note, I did successfully diagnose my Joust. It'd seemingly randomly stop working when moved. I thought maybe it was a cold solder joint, but upon a tip I learned here, I pressed lightly on the ribbon cables and observed the error codes. They would change as I pressed on the cable between the ROM board and RAM board. Upon closer inspection, the strain relief was broken and some of the wires were loose. So I need to pick up a new cable.

 

[jacklick]

your power supply looks like all the ones I have seen. Off top of my head, I do believe there is only one +5v line to the rom board. I have a couple videos on my joust if you need something visually to refer to.

 

[Arcadenut]

Post a picture of your ROM board. The manual does show two +5V on connector 2J2 on pins 4 and 6. It's possible someone modified the harness for some reason (I had a Joust someone mucked with the wiring on). I'll look at my Joust and see what it has.

 

[Arcadenut]

Looking at mine, it looks like I added the second +5V wire on mine. Not sure if they only ran one +5V line to the ROM board from the factory. Can anyone else with a 100% original Joust look at their wiring?

 

[Arcadenut]

Ok, found this thread:

Joust Help

Joust. 3 little lights turn on, on board inside cabinet. No lights or digital number lit on DOOR PCB. Monitor turns on, neck glow, and some response on screen. No sounds.

forums.arcade-museum.com

The picture in there shows only 1 wire going to the +5V on the ROM board.

 

[olePigeon]

http://arcarc.xmission.com/PDF_Arcade_Williams/Joust_Drawing_Set_(16P-3006-103)_Sept_1982.pdf

This one matches. Odd. Maybe I was looking at the wrong manual? Sorry for the bad post. I thought I was looking at the Joust manual. Still has the 2nd 5v on it, though. Maybe it was revised on later versions of the game.

 

[Arcadenut]

http://arcarc.xmission.com/PDF_Arcade_Williams/Joust_Drawing_Set_(16P-3006-103)_Sept_1982.pdf

This one matches. Odd. Maybe I was looking at the wrong manual? Sorry for the bad post. I thought I was looking at the Joust manual. Still has the 2nd 5v on it, though. Maybe it was revised on later versions of the game.

There are two versions of the drawing set. It's not unusual for manuals/schematics to not match reality. Things change on the production line and a lot of the times they didn't want to waste the resources to update the documentation.

 

[Arcadenut]

http://arcarc.xmission.com/PDF_Arcade_Williams/Joust_Drawing_Set_(16P-3006-103)_Sept_1982.pdf

http://arcarc.xmission.com/PDF_Arcade_Williams/Joust_Drawing_Set_(16P-3006-103%20Rev%20A)_Dec_1982.pdf

 

[Arcadenut]

If you measure the voltage at the ROM board and you're getting close to +5V then you're fine. If it's too low you can run a second wire to that other pin and that should improve it a bit.

 

[security0001]

that is the primary PS in your joust (williams D8784) and it needs a rebuild with all those original 40 year old caps.

Williams D-8784 5773-09679-00 Power Supply 105C Cap Kit-Arcade Parts and Repair

Williams D8784 Arcade Linear P/S used on Joust, Robotron 2084, Stargate, Sinistar, Bubbles, Moon Patrol & Blaster other games Mega Deluxe Cap Kit

www.arcadepartsandrepair.com

 

[mecha]

I used to do the double wire mods, as there's some empty pins for +5 and ground (these were used on games with optical joysticks like Sinistar, Bubbles, and Blaster later) but the change is so negligible it's not worth doing. you'll get more mileage out of replacing parts on the power supply. caps, headers, BR1, 3055 transistor, LM723 voltage regulators, plugs and the one wiring mod that will benefit you significantly over time is the double 22.5V AC transformer mod.

do not replace BR2 and do not do the voltage adjustment mods. there's about 5 active threads where I keep repeating this, this is what I do, take my word for it. or don't. it's seeming more and more like I'm wasting my time continuing to post here.

for the record it's entirely normal to have just 5.0V to chips on the boards. you don't need more.

 

[olePigeon]

It's still running appropriate voltages, but yeah, my intention is to recap it anyway. I could do a rebuild, but money is tight right now.