(Topic ID: 109477)

Tech helllllllp!: BTTF New power supply, now doesn't boot

By DropTarget

6 years ago

Topic Stats

  • 8 posts
  • 5 Pinsiders participating
  • Latest reply 6 years ago by DropTarget
  • No one calls this topic a favorite


Linked Games

#1 6 years ago

Hi All,

If only I had hair to pull....

I have a BTTF which had an intermittent GI issue. I attempted to fix by changing out the CN8 connector and header. I did a sloppy job of replacing the header, and now no GI.

So, I ordered a new Rottendog power supply board. After replacing the board, the GI worked. However, nothing else does.

Jim was very helpful on the phone, and I seriously doubt that his product caused the problem.

Here's what happened. At first, the game booted and played but no sound. Then it booted but didn't play. The display said "one ball missing". After turning the power on and off again, the GI lit, but nothing else. No boot, no display's, no sound.

The MPU blanking LED never comes on, while the +5 stays lit all the time, and the PIA comes on, stays on for much longer than normal (a few minutes) then sometimes goes off, but comes back on, sometimes flickers.

Any suggestions?


#2 6 years ago

Have you:
Checked power supply board (replace filter caps, check for stability, less than 500mV AC ripple on the 5VDC rail) ?
Rebuilt power supply connectors, repinned cables?

#3 6 years ago

agreed...test power output of the replacement power board. Sometimes they can be bad due to shipping etc...

#4 6 years ago

90% of me says cables most likely. Did this game ever have battery corrosion on the MPU?

#5 6 years ago

What happens when you put the original board back in that had no gi? Does it boot then?

#6 6 years ago

New board is putting out 5.01VDC, The MPU has 4.9 coming in to it.

Original MPU, no battery damage. From what I'm reading, the LED sequence suggests that the game ROM's went bad, or possibly the PIA chip. It's a funny coincidence, but maybe something spiked and the chips were on the way out. I dunno. I'm sending out the MPU to be checked.

Good idea replacing the old power supply, but it was hacked (previous to me), a few of the molex housings were removed, and the wires soldered directly to the board. In order for me to connect to the new board, I had to cut the wires and added new molex housings.

It would be a problem to do that.

#7 6 years ago

I was hitting cold solder points on my MPU and when I put it back in the cabinet it wouldn't boot, I cried for a minute, then noticed that "tapping" the battery box kicked the power on and off, missed the cold solder points on the battery holder. Cleaned them up and the beast fired right back up ike brand new!

#8 6 years ago

good catch.

I sent my board out to be tested, I should know more in a few days.

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