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tim
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« on: June 30, 2006, 02:23:39 PM »

Company : Gottlieb
Cabinet : Dedicated upright
Monitor : 19" vertical color raster



I picked this one up from Gaymond Lee. It wasn't working. Dead, no video. The cabinet is in great shape. The cardboard EFI shield around the boardset had never even been opened. The factory staples were still in place. The inside of the game was very clean and there were even two quarters in there. This is how I like to get games... In great condition but dead, so they're cheap.

The cabinet needed a good dusting and cleaning. The control panel looks good, but with the usual cracking at the bend. The joystick was the worst part. The insert with the Gottlieb logo was missing and the two halves were taped together with electrical tape. I took it all apart and threw away the sticky, messy handles. I picked up a new stick for $8.27 from eBay but it didn't have the joystick insert either. I didn't have a clue what one was supposed to look like, so I drew my own. Here is a pic of how it came out. Later the same day, my buddy, Stephen Beall, sent me a picture of what it's supposed to look like. Not too close. I don't think I can redraw that. Oh well. I guess I'll keep an eye on eBay for one.

I opened the EFI shield and the first thing I noticed was that the high score battery on the main PCB had leaked. The acid was slowly spreading and dissolving the PCB. I removed it right away and got some white vinegar and cleaned up the mess. Then I dried it off and tested continuity on all the corroded areas. It hadn't eaten completely through anything, thankfully. I hooked up the PCB on my test bench and got good video. Groovy.

I put the PCB back in the cabinet and powered up. Blank screen, no life. I noticed the +5 LED on the power supply was not lit. I wiggled the connectors on the power supply and I heard a brief sound from the speakers, saw a flash of light and heard a pop. Fuse F4 blew. Bad solder joints, I figured, so I unmounted the power supply and checked out the back side. Sure enough, big-time cracked joints. I reflowed and added some more solder to the pins on each connector, replaced fuse F4 and gave it the juice. This time we got a +5 LED, but the screen is just showing random junk and the speaker is spitting out weird noises. After a few seconds I heard another pop and F4 blew again. This time F11 on the power supply blew, too. Hmm. I replaced F4, but left F11 as-is and put the volt meter on the line. It's supposed to read +11.5 vdc. It does for a few seconds, then slowly drops down to 0v. Hmmm. Looking at the schematics, there's not much there -- just a rectifier and a huge capacitor. I don't have replacements for either of those, so I decide to wire in a switching supply until I can get new parts. Rather than cut up the harness, I'll make adapters to plug the switcher into the existing connectors, so I can easily unhook it later. The schematics look like the only place the 11.5 vdc goes is to the power supply where it gets converted to +5v for the main PCB. So, I hooked the switcher up to the cabinet's AC power, down-line from the last power switch so the cabinet switches will turn on the new supply. After wiring it up, the game does practically the same thing, but without blowing any fuses. I test the voltages at the main PCB and there's no +12 where it belongs. A close look at the schematics again show that same 11.5 vdc does indeed sneak off to the main PCB as well. So, I hook up +12 from the switcher and give it the juice again. This time we got all good voltages at the main PCB. A walk around to the front and there's a nice clean picture greeting me. Yay! I add some credits and start a game and it's working just dandy!

Things to do: Find a new joystick insert with Gottlieb logo. Replace the bad rectifier and/or capacitor on the power block. Replace flaky volume pot. Replace a diode on sound board which is notorious for failing and putting 43 volts into the sound amp. Add Dallas NVRAM to save high scores.

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