Triple Double Diamond & DD Deluxe Board - Removed Varda now issues

[stlscott]

Hi eveyrone, I'm back with my machine drama again.. LOL

So I have a machine (pic included) that I swapped reels & MPU so my Triple Double Diamond would play Double Diamond Deluxe (using a 2nd 502, with the DDD on it).  Prior to removing the Varda batteries on the original 502 board and the DDD 502 board, everything worked perfectly on both boards.  I worked out all of the problems and issues before removing the Varda so I wasn't chasing my tail on more than one problem.  So over the weekend, I went ahead and removed the VARDA battery from both of my 502 boards.  The TDD does not have any issues at all, the DDD now does.  It starts to spin reels and throws a General Tilt error and Open MB error.  I read thru lots of the forums and most say something about optics but that has already been bypassed and everything is on the white switch (and it works properly).  I also let the reels spin with the door open (pressing on the button) and they spin and still TILT.  Sometimes it will get the 1st and 2nd reel to stop before tiling on the 3rd and sometimes it tilts before stopping any of them or just one... seems random.  There does not appear to be any damage on the MPU board, again pics are attached.  I did a KEY and went thru all of the settings, just to make sure, and all good... Machine is in UPRIGHT, Hopper set to 0, TITO still works correctly, tickets print, bills are accepted.  Sometimes, it will play 1 or 2 games before the general tilt, sometimes it does it right away.  I've swapped back to the TDD board on the same reels, NO TILT after 20-30 games.  I switched reels from the TDD and used them with the DDD board and they also tilt the same way so it's the board.  What can I look for?  I was very careful with the soldering... 

[lookes]

Carefully remove U79. If it is still acting up there probably is trace damage, or something else.

[stlscott]

Is it possible that the trace was damaged during solder removal?  Not sure what that trace does

[stlscott]

Carefully remove U79. If it is still acting up there probably is trace damage, or something else.

I thought that on the 502 all you had to do was remove the battery, unlike the 1270....

[lookes]

Trust me. Every 50X I work on gets U79 plus 8 other parts removed. The only thing I see is the trace next to the Varta hole furthest from the board connector edge. It would cause a bill validator door error that would stop the machine in the middle of a spin even.

[stlscott]

Trust me. Every 50X I work on gets U79 plus 8 other parts removed. The only thing I see is the trace next to the Varta hole furthest from the board connector edge. It would cause a bill validator door error that would stop the machine in the middle of a spin even.

Right by the "U84" lettering?  That's what I was thinking, I will try and do a continuity test on the trace line.  It's the only place that looks like possibly missing.  I couldn't see that with my eyes but when I zoomed in on the pic, it looks like it might be missing... but there isn't damage to the actual board... which seems odd....


What else should I remove?  I've not done any mods to this board (yet).  I've thought about doing the audio mod as it buzzes during spins because I have the Audio-Lite board on it (i just love to switch out game sounds!!)

[lookes]

Yes. Right by the lettering. It's discolored. I can't tell for sure.  The other parts I remove aren't directly related to door open faults.

[stlscott]

Yes. Right by the lettering. It's discolored. I can't tell for sure.  The other parts I remove aren't directly related to door open faults.

Thanks for the clarification, I will try and test that trace tonight with a meter. 

As for the "other parts" you remove, can you say which parts and why?  I would rather avoid problems in the future by doing all of the work upfront.  If there is a "better process" of doing board clean-up, I can do that.  I'd love to know what you remove and what the reason/benefit is.... thanks so much!

[stlscott]

Well I think I need a microscope to follow this trace... OMG it's near impossible... like high speed chase with a motorcycle with over/underpasses..

Anyway, I took another real good close-up of the area under the Varda and it doesn't look like the trace is damaged... your thoughts???

[lookes]

It looks OK but use your continuity meter and test pin 33 of U69 to pin 9 of U60. Should be zero ohms or so.

This photo looks like you have not removed U79 yet. ALWAYS remove U79 when removing the Varta battery on all 50X boards. It may work without removing it, or it may intermittently give false open doors faults, or eventually fry your door optic emitter.  Without the Varta to sink some current, the charge controller can have voltage swings of about 2V to over 10V put on the quite complicated door security circuitry.  Whether it works or not without removing U79 just depends on other components' in the system's combined tolerances.  At least try it. It may not be the problem but you need to try it first.

[stlscott]

Thank you so much, I will be removing U79 this weekend.  Thanks for the guide on where to test continuity!  SO helpful as always!  I will report back (as I always do) after I follow your suggested steps

[stlscott]

It looks OK but use your continuity meter and test pin 33 of U69 to pin 9 of U60. Should be zero ohms or so.

This photo looks like you have not removed U79 yet. ALWAYS remove U79 when removing the Varta battery on all 50X boards. It may work without removing it, or it may intermittently give false open doors faults, or eventually fry your door optic emitter.  Without the Varta to sink some current, the charge controller can have voltage swings of about 2V to over 10V put on the quite complicated door security circuitry.  Whether it works or not without removing U79 just depends on other components' in the system's combined tolerances.  At least try it. It may not be the problem but you need to try it first.

When I look at IC U69, is pin#1 on the left side or the top side?  And which direction do I go to "count" to pin #33.  On U60 is pin #1 on the left side of the IC at the top by the divit/dot?  I just want to test with the right pin#s and not sure how to find them.  Thanks again for your help.

[stlscott]

My wife, who repairs X-Ray equipment helped me.  On the U69 she counted starting at the top left (based on the pic I posed), across the top, down the right side and to find pin 33.  On the U6, she started with pin #1 on the left side top because the dot is off-center to the left and started as pin-1 there counting down the left side to find pin 9.  THere was no continuity between pin 9 and pin 33 based on that information.  Should I run a jumper wire between these two pins?

[lookes]

Pin 1 is marked on the board on U69. It's in the middle of the side the furthest away from the connector edge. Count from the pin marked 27 on the bottom of the chip to the right.

[stlscott]

Pin 1 is marked on the board on U69. It's in the middle of the side the furthest away from the connector edge. Count from the pin marked 27 on the bottom of the chip to the right.

Thank you for the help, using this information, pin 33 was in the bottom corner of the square IC.  Yes we had 100% continuity between Pin 33 and Pin 9.  We then removed the U79 and that seemed to have resolved the issue.  This machine did not have optical switches (bypassed already) but obviously the U79 was causing problems as you suggested. 

What is strange is that my other 502 board that I removed the Varda battery on also (removed Varda from both boards at the same time) still has the U79 and does not have any tilts or errors with 100+ games played on it after the Varda removed, in the same cabinet.  I will be removing the U79 anyway as you recommended, but just thought I would add that info.  Both boards are 502's, only difference is that one board has the Double Diamond Deluxe game chip and the other has Triple Double Diamond.  Otherwise they are the same.