(Topic ID: 166813)

Lethal Weapon 3 resetting. Need some advice

By Grangeomatic

7 years ago



Topic Stats

  • 9 posts
  • 4 Pinsiders participating
  • Latest reply 7 years ago by mikat11
  • Topic is favorited by 1 Pinsider

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#1 7 years ago

My buddy's got my Lethal Weapon at his "up north" cottage for the summer, and its giving him some problems. He's done some initial troubleshooting, with no luck. Trouble is, neither of us are actually by the machine right now. We want to get it running when we're both up there over Labor Day, so I'm looking for things to look for, parts to have ready, or any other advice you can come up with.

Here's what we know:
- sound board started acting funny first, like it was resetting in the middle of a game, then the sound stopped working altogether
- next, it started resetting completely mid-game
- now, he tells me that the board will boot up at first, then just die, doing nothing
- he measured some voltages, and found that the +5V is only at 4.65V, so were thinking that's likely the problem
- he disconnected everything from the power board, and it was still 4.65 at the power supply with nothing connected
- I replaced that little electrolytic cap at the corner of the big heat sink within the last year
- he took the power board home for a bit, but with no machine to put it in, his options were limited. He replaced C1, C2 & C3 on the power board on a whim. When he got back to the cottage, no luck.

So, when we're both up there for Labor Day, I'd like help with a plan.
Anything else I should look at?
What parts should I have on hand?
How can I check the voltage regulator (I don't fully understand that circuit)?
I know these Data East machines are basically clones of Sys 11. If I have a Sys 11 power board (Cyclone, Pinbot), can those be dropped in for a test?

Anything you can share would be appreciated.
Thanks,
Jeff

#2 7 years ago
Quoted from Grangeomatic:

He replaced C1, C2 & C3

Quoted from Grangeomatic:

I replaced that little electrolytic cap at the corner of the big heat sink within the last year

Good guesses.
Some of those leak and could have been the culprit.
If the voltage at the LM723 5V regulator pins 4 and 5 is different, then the regulator has failed.

Since the game is remotely located, if you can't get it working, snatch all the boards from it (power, MPU, Sound) and send them to a pro. Spend your time fishing and playing pinball rather than fixing pinball.
--
Chris Hibler - CARGPB #31
http://ChrisHiblerPinball.com/contact/
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info

#3 7 years ago

Or you could get a Rottendog replacement power board and repair the stock unit later and sell it to help pay for the Rottendog . No more worries. It doesn't get any easier than that.

#4 7 years ago

As a follow up you will want the Rottendog DPS005 for a Lethal Weapon 3. They are available from several sellers. If you do ebay big daddy enterprises sells them for $117.95 with free shipping

#5 7 years ago

Rottendog is something I hadn't thought of, mostly because I'm cheap, but also because I get a certain pride out of fixing rather than replacing. I will give that some serious thought, though.

Would you all agree that 4.65V is too low, and this is where any repairs would need to start?

#6 7 years ago

Yea 4.65 is way too low. Any reading below 5 volts at the power board test point can cause problems. Chris Hibler may be correct about the LM723 regulator or possibly the other 5 volt regulator 2N6057 is out of whack. Thats the one mounted to the big aluminum heat sink. Cap C7 is in the 5 volt circuit as well 330uf/25v. Also make sure there is 18volts AC (give or take a couple volts) to connector 1 pins 10 and 11 on the power board. This primary voltage is rectified to provide 5 and 12 volts DC. Set your meter to AC and probe those two pins to verify. Bridge 1 (cm 3501 could be suspect too).Several possibilities to check and difficult to cover everything when the machine is far away. Thats why I suggested the Rottendog. Good luck.

#7 7 years ago

Another follow up. A common Data East/Williams problem is the connector 1 on the power board I mentioned tends to get hot and burn the male and female pins inside the plastic housing and cause bad solder joints on the power board and could result in a low 5volt problem. If the housing is a brown color from getting too hot in the pins 10,11,12 area the pins in the housing and pins mounted to the board may need to be replaced.

#8 7 years ago

Just replace it. Fix the old one at your leisure, and sell it.

#9 7 years ago

I would but remember check connector 1 just in case.

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