Qbert question.

jkoolpe

Well-known member
Joined
Apr 21, 2005
Messages
2,563
Reaction score
765
Location
San Bruno, California
Hey all!

Well, I finally picked up a decent Qbert for myself (yea!). Can't wait to get Mike Doyle's multiboard when it becomes available. I even have some NOS CPO and front panel art to apply.

It does have some issues, but the cabinet is pretty nice. For whatever reason, it appears that the power supply is only putting out +4 volts instead of +5V...the game comes up, but it's now stuck on the opening screen after I hear Qbert's voice (so hopefully this means that the sound board is good :) ). It won't go into test mode.

I'll get Arcade Shop's replacement power supply regardless.

Anyway, I'll go through it a bit more tomorrow, but I was wondering:

I have an extra Gottlieb CPU/Main board that was from a Mad Planets. Are the Gottlieb main PCB boards interchangeable (between Mad Planets and Qbert with just a ROM swap)?

They sure do look the same...the only difference I could see beyond the ROMs was that the Qbert board had one extra 6116 RAM chip (of which I have plenty so I can easily add it to the empty socket on the MP board).

Thanks!

Jon
 
I had the same issues on my Qbert recently. I had cold solder joints on the back of the filter board. I could flex the filter board and the Game would come on intermit, try re soldering the filter board. Good luck
 
Cracked solder joints on the filter board are very common. You can try adjusting the +5 pot on the power supply. Qbert will run at 4.5v but anything lower and it will hang or have graphic issues. You will find that you have to crank the pot almost all the way to get it to +5 on the main board.
Yes, im pretty sure mad planets pcb is the same with a rom swap. I have power supply rebuild kits in stock if you want to rebuild yours. The switcher will get you up and running but your going to have issues with the knocker.
 
Cracked solder joints on the filter board are very common. You can try adjusting the +5 pot on the power supply. Qbert will run at 4.5v but anything lower and it will hang or have graphic issues. You will find that you have to crank the pot almost all the way to get it to +5 on the main board.
Yes, im pretty sure mad planets pcb is the same with a rom swap. I have power supply rebuild kits in stock if you want to rebuild yours. The switcher will get you up and running but your going to have issues with the knocker.

Thanks guys.

I actually have an extra PS come to think of it...it was from my Mad Planets and I removed it when I put in the Arcade Shop PS replacement awhile back. It worked fine (after a rebuild on my part :) ) at the time so maybe I'll try that.

I will also pull the filter board and reflow the solder...I think someone already did it, but I'll do it again. I did notice that 2 of the connectors (the 2 smaller connectors at the very right of the filter board) were bypassed in that the wires were clipped and soldered directly to each other. But the owner said the game had worked for awhile but went down only because it had been in his storage space unused for some time.

So the Arcade Shop PS has issues with the knocker? I read something about that...what does it do/not do? My problem with it was that the original connectors had the wires coming in at right angles so that there just wasn't enough space on the adapter board that comes with the new PS to physically fit them in at the same time...I had to replace the larger, 16 pin connector (P4) with a new one where the wires came in from the top to make it fit (again, for my Mad Planets). I'm expecting to have to do the same if I get this for the Qbert as the connectors are again the right angle type.

Jon
 
Aux pcb

The aux pcb gets really hot on the far right header pins and the ones below it.. That's we're most of the voltage goes. Instead of reflowing the solder on those 2, replace both sets of header pins with new ones.. Also cut off each connector or make new ones as yours has been directly soldered to the pcb..

I just rebuilt 2 aux pcbs and have one more to go.. Once you replace the header pins, then you can reflow the solder on all the rest of the pins.. Make sure you rebuild the power supply from your mad planets! As the 30volts can really make a mess of your game if it's too high..

The arcadeshop ps lowers the voltage to the knocker, that's why it won't knock as loud, or not at all.. But it does take the 30 volts out, which is a good or bad thing depending on what you want..

Make sure to remove the battery off the CPU pcb if it's still there!! It's the black box that says data sentry.. Replace it with a cordless phone battery or watch battery with resistor mod..
 
The aux pcb gets really hot on the far right header pins and the ones below it.. That's we're most of the voltage goes. Instead of reflowing the solder on those 2, replace both sets of header pins with new ones.. Also cut off each connector or make new ones as yours has been directly soldered to the pcb..

I just rebuilt 2 aux pcbs and have one more to go.. Once you replace the header pins, then you can reflow the solder on all the rest of the pins.. Make sure you rebuild the power supply from your mad planets! As the 30volts can really make a mess of your game if it's too high..

The arcadeshop ps lowers the voltage to the knocker, that's why it won't knock as loud, or not at all.. But it does take the 30 volts out, which is a good or bad thing depending on what you want..

Make sure to remove the battery off the CPU pcb if it's still there!! It's the black box that says data sentry.. Replace it with a cordless phone battery or watch battery with resistor mod..

Actually, nothing is soldered directly to the filter or to the PC board...it's just that the wires were clipped from each of these connectors to the filter board and fused together directly which bypassed the board for these 2 connectors. Would that be a problem in the long term? I thought that the filter board is essentially not really needed per se and was just a concession to the FCC at the time which was concerned with electrical "noise" from these old games that might have interfered with stuff like TV and radio signals. But I can replace them both if you think that would be a good idea. LMK...

I'm pretty sure I had rebuilt the MP power supply already (and it was working fine in my MP for a few years before Arcade Shop came out with their replacement). But I'll double check on that and make sure.

And yep, the original battery was already replaced with some sort of upgrade...it looks like 3 lithium ion batteries melded together. I would have taken the original battery off or there right away if it was still there :).

Jon
 
They just bypassed the filter board by soldering those wires together. That particular connector is very prone to burning up. If your feeling energetic and have some time to kill you can bypass the entire filter board and be done with it forever.
 
Is the only problem w/the Arcadeshop Power board the knocker support?
 
Update:

I got it working :) !

I reflowed the solder on the original power supply board, and then upped the voltage a bit with the pot, and voila! The game came right up...full sound, and even the knocker works fine.

I'll still recap the PS board and probably pick up the Arcade Shop supply eventually, though.

I also capped the monitor while I was at it so now the picture is real nice.

Not bad...wish all fixes were as easy.

Now I can't wait for Mike's multikit which I have on pre-order :D .

Jon
 
Is the only problem w/the Arcadeshop Power board the knocker support?

One issue some people have run into is the fact that the video board still needs +12VDC to operate. The +12VDC comes from the power brick in the base of the cabinet and then goes to the video board, encounters a zener diode configured as a voltage regulator, and ends up feeding a single chip (a memory addressing chip) with about 5 to 6 VDC.

That being the case, you still need the +12VDC generated by the power brick in the Q*bert power supply. Of course, if it is missing, you can always just run a +12VDC (regulated) line from your switcher over to your video board if you want.

Soooo... if your +12VDC unregulated is fine and all of your cabinet wiring is intact, your cabinet should work ok with the Arcadeshop power setup. If your +12VDC unregulated from your brick is bad/missing, then video board will not run, even with the Arcadeshop setup installed.
 
Just so you know, I have done every mod known to man to my Qbert (AS Power Supply, New filter cap on the transformer, rebuilt soundboard (both U16 and U17 replaced), New sound chip on the main board, reflowed filter board, Doyle's 8 in 1 kit, rebuilt monitor) and I still have issues with my Qbert, EVERY TIME I turn it on. Frozen sounds on start up, interference rods in the video, sound goes out during gameplay and will come back if the multi kit is rebooted to the menu, etc. It will play fine for several hours one day, and will go out within 10 minutes the next. I have just gotten used to it.
 
You don't need any battery back-up when using the 8 in 1 Multi Q*bert, so you can skip that step in your game's resurrection.

The Multi kit writes to it's own serial eprom when you hold P1+P2 to exit to the menu. It also handles the read/write routines between itself and the old Gottlieb board, storing settings and scores on the Multi kit in a non-volatile format that doesn't require the battery.
 
[QUOT;/=Mike Doyle;1835376]You don't need any battery back-up when using the 8 in 1 Multi Q*bert, so you can skip that step in your game's resurrection.

The Multi kit writes to it's own serial eprom when you hold P1+P2 to exit to the menu. It also handles the read/write routines between itself and the old Gottlieb board, storing settings and scores on the Multi kit in a non-volatile format that doesn't require the battery.[/QUOTE]

Great! Thanks for letting me know as I was just about to buy the backup kit :) .

The current battery upgrade that was already present when I got the machine does work for now, but I'll be getting your kit as soon as it's available so it'll all be irrelevant thereafter.

Jon
 
Back
Top Bottom