502 rev a. No door and no varta damage fixed.

[Retro tech repair]

I have started doing 500 series board repair i just got done fixing 13 boards. 7 of the 13 were all 502 rev a boards with the same fault no varta damage and no door optics. In testing i found the sense line was never being pulled up. I checked the pull up resistors for the doors and there was not continuity between them and any vdd sources I checked. I ran a jumper from one of the resistors r115 directly to vdd of the regular and the doors worked.

[Tilt]

Nice find.  Seems like a trace is damaged somewhere though.

[Retro tech repair]

Nice find.  Seems like a trace is damaged somewhere though.

The boards are all clean I think they were overheated when the vartas were removed and it cracked a via

[DB26]

Great info! Your work will no-doubt help many people repair boards for years to come. Do you have a picture of the jumper you ran? Just in case I run into the same info when attempting repairs on my boards.

[Tilt]

Nice find.  Seems like a trace is damaged somewhere though.

The boards are all clean I think they were overheated when the vartas were removed and it cracked a via

That's a possibility.  Would have to try to trace out the trace and see where it goes.

[DB26]

Any pictures? I am trying to repair a board tonight. It’s not seeing the door optics and I’d like to try your fix.

[DB26]

I actually found a few more traces that were bad. That got rid of the “please close the main door” problem ...somewhat. Now it’s intermittent. The machine will run fine for a minute and then “flash” the door open message on and off for another minute. I have a video showing it. Any idea what to check? More traces probably? This one did have battery damage.

http://youtube.com/shorts/KXjGQuYi8g4


I would still like to see your repair, though. I believe my next board in my stack is exactly what you described. No Varta damage and the door open message. I’d love to give your fix a try.

[Stayouttadabunker]

Ohh...I had a board that did the same thing as yours...flashing on and off... if I hit the spin button, I had gotten the reels with the slow spinning errors... 

I ended up having to find a new MPU board.

[DB26]

Ohh...I had a board that did the same thing as yours...flashing on and off... if I hit the spin button, I had gotten the reels with the slow spinning errors... 

I ended up having to find a new MPU board.

Yes, mine did a general reel tilt as well. The board is getting better though! I repaired a few more traces and now the flashing on and off happens much less often.

I think what’s happening is that there are traces that test good, but when the board is installed and the machine is running, they heat up and lose continuity. And once they lose continuity they cool down again and reconnect.  That then makes the machine think the door is being opened and closed repeatedly. When the machine is playing a game, if the traces lose their continuity, the machine thinks the door got opened and then it tilts.

What I will do now is go to all the traces that previously tested good, but have dark spots where acid damage had begun and add jumper wires to those. That’s what I did last night and it almost made my problem go away. Almost there!

[Stayouttadabunker]

Sounds more like a transistor or triac switcher over heating? I'm not sure.
I wouldn't know how to test or find out which one is going outta specs. 

[Trisail]

Reflow the connections on the edge connectors too. I fixed a couple reel tilts by just doing those connections for the stepper motor drive signals. Maybe do them all. The reels pull more current than most other circuits which is probably why they had bad/cold solder joints. Might help, probably won't hurt.

Tony

[rdpp1]

I have started doing 500 series board repair i just got done fixing 13 boards. 7 of the 13 were all 502 rev a boards with the same fault no varta damage and no door optics. In testing i found the sense line was never being pulled up. I checked the pull up resistors for the doors and there was not continuity between them and any vdd sources I checked. I ran a jumper from one of the resistors r115 directly to vdd of the regular and the doors worked.

Hi All,
I am facing exactly the same issue, and find a repaired/working Board in France is really a pain... So I would like to repair mine, do you have some pictures? or details to help me? 

there is the picture of my board:


Thank you for your help

[Nurbo]

Hello Retro Tech repair and thank you for this information.

Like the other members, I'm wondered to konw about what Vdd regulator do you talk about.

If I look at the diagram, I found R115 under the green Varta battery of the other side of the board, with possible acid corrosion on this trace.

I drawed in red the trace from Vdd to R115 pin1, but where is the Vdd regulator do you talk about ?

[DB26]

I would still love to see a photo as well!