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Stern mini display problem

andy

andy

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Jul 21, 2011
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I bought a Monopoly recently which I've just set up. Either I didn't notice when I collected it or something has happened in transit but the Electric Company mini display is not displaying correctly.

In gameplay some words come up ok but some are garbled / flickering. In 'all dots' test all the dots come on and in horizontal line test all lines are shown, but in the vertical line test only lines on the right side of the display come on.

I've reflowed the solder on the connector on the mini board and J2 on the driver board to no avail. Before trying to look any further I just wondered if anyone else has had problems with this display, or the slot machine display on a High Roller Casino, and if so did you find a solution?

Thanks very much,
Andy
 
Thanks for the offer but I don't think it is - the TSPP is bigger and multicolour - and the one in Roller Coaster Tycoon is different too.

If anyone thinks I'm wrong in any of that please say so though as I've never actually had either game! o_O
 
reseat any relevant connections,whether data ie ribbon cables or other normal connections - both ends.
I.e at the board at fault and the reciprocal end
 
Thanks Poibug.....still no joy though. :(

I've now seen there's a Stern service bulletin about the mini display saying to suspect U201 or U206 on the driver board if there are problems. U201 looks to have been replaced already, and from the schematics U206 seems to be on the Aux In circuit not the Aux Out that drives the display - however not being an electronics whizz I may be misreading it. :confused:

Anyway, before any chip swapping I'll stick the driver board from my T3 in and see if that makes any difference to try and isolate where the problem lies......
 
Well, that service bulletin also mentioned ensuring the wiring to J2 on the driver board wasn't too close to the AC input on J17.

Moving the J2 loom away (right away, routing it round the bottom of the board) has resulted in a fully working display! :) Well, nearly, it's mostly fine and steady and all lines now show up in test, but when the GI relay is energised (so turning the GI off, mostly for the bonus count and after the match) there is still distortion on the display. As soon as the relay de-energises the display returns to normal.

However........if I ground the relay so it's always energised the display is fine, except for when the machine *should* be energising it. Looking at the schematic the transistor for that relay is controlled by.....U206!

I'll source a new 74HCT273 and see if that solves it!

Andy
 
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Nice detective work! Maybe I should post the MPU from Gold Ball back to you so you trace yet another fault that means it isn't working again ;) Took me a week to get it going, then spent another week fixing the PSU, mains wiring and the regulator board, put it all back in the cabinet and the ruddy MPU isn't booting again. Grrrr... :mad:
 
Peter you are doing sterling work (to say the least) on the Gold Ball and I'm really enjoying your shop log! Though I do feel guilty when you list all the things wrong / broken. It *was* cheap mind ;)

Also if I still had it it would still be sitting there in 10 years time! Then when I finally plugged it in I'd probably give up on it when it got too difficult...... :rolleyes:

Looking forward to the vid of it up and running!
 
andy said:
Peter you are doing sterling work (to say the least) on the Gold Ball and I'm really enjoying your shop log! Though I do feel guilty when you list all the things wrong / broken. It *was* cheap mind ;)

Also if I still had it it would still be sitting there in 10 years time! Then when I finally plugged it in I'd probably give up on it when it got too difficult...... :rolleyes:

Looking forward to the vid of it up and running!
Click to expand...

No worries, Andy! I'm not trying to name-and-shame you or guilt you in to fixing the MPU (although that would be nice) :p

I'm still 100% chuffed to bits with my purchase of GB :D I love that it's rather rare, not terribly popular and has a unique circuit board that is almost totally undocumented. In typically British fashion I'm a bit of a sucker for the underdog and rather like a challenge.

I wasn't surprised or disappointed by any of the issues on GB. I can handle just about anything electronic. The main thing is stuff like the playfield and plastics are all good. Those sort of bits would be a bugger to replace. A few chuffed chips or suspect wiring is easily rectified.

I too look forward to posting that first vid! Thought it was going to be this weekend... But soon... It'll be soon...
 
Just to finish this thread off and in case anyone else has this problem, this evening I replaced U206 and also the 2n3904 GI relay driver transistor and the mini display is now strong and bright in all cases and working perfectly!

I'm still not sure how these components affected the mini display but I'm just happy to have solved it! :)

Next time I'll try and notice something not working properly before I actually buy the game though...... :confused:
 
hI aNDY,
oLD topic but looks very interesting to me. Im also having issues with the mini dmd on my Stern. So now i will replace the U206 chipset and Tip 102... im really curious if this will solve my problem.
Thanks !
 
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