PS3 Board Running Hot

Those look to be multi-layer ceramic capacitors. Dave always comes through with explaining why and how. https://www.youtube.com/watch?v=QgKY5QWehME

@ScottM posted:

I have been in the process of servicing my friend's PS3 upgraded MTH Veranda Turbine and have been presented with many challenges, including multiple frayed & pinched wires, a blown power chip resulting from one of those wires, and a bad tach reader. The power chip was replaced by a certified tech.

but one issue remains: the temperature of the main board. Using the temperature probe on a multimeter, I measured 110F on the components circled (it actually feels hotter). The same type of components on the left side of the board also feel hot.

#1 this board was abused in the past with shorts and overloads. So much so it burned up at least one component.

#2 that component was replaced, but only that component and as part of the soldering process, nearby components such as these capacitors may have been heated or subjected to thermal and mechanical stress during that soldering repair.

#3 They tend to fail shorted with ever lower and lower resistance as more of the layers short, and thus as they fail generate tons of heat further causing failure.

It's pretty hard for me to imagine multiple cap failures of that nature.  I might buy one on a board...

This is the study in the video: MLCC-FailureModeStudy-032012.pdf

I'd eliminate the first two categories right up front, obviously the design isn't that bad as thousands of these boards have been shipped and are fully functional.

Before I'd suspect the board, I'd want to see how this board reacts in a different environment.  Obviously, I'd put it on the test stand and see how it functioned, but swapping it to another engine would be a useful exercise since I doubt you have a PS/3 board tester.  I'd also be looking very closely at the rest of the engine, and perhaps doing things like checking the motor current for each of the motors using a DC bench supply.

The board will get hot with power going to the track but the engine not "awaken". I have thought about placing the board in another engine. Perhaps a simpler test would be to remove the large connector and leave just the power/motor connector.  Would that not effectively eliminate any other environmental factors?

Also, can these capacitors be tested and replaced?

The caps can certainly be replaced, but I'd want to see what could be causing the issue before starting to rip stuff off the board.  Also, we don't know what value they are, and it's difficult to impossible to check value in circuit.  My choice would be to move the board to another engine and see if it behaves there.

@gunrunnerjohn posted:

My choice would be to move the board to another engine and see if it behaves there.

I will try to do this tonight. I'm assuming the test will not include the slave board?

Nope, you don't need the slave board, just see if the master has the same issue in a different engine.

@ScottM posted:

I will try to do this tonight. I'm assuming the test will not include the slave board?

No.1 rule before doing an upgrade is making sure the engine/engines you’re upgrading are 100% mechanically sound before adding very expensive electronics….as John suggested, I’d verify each motor is good before I did a thing, and I go as far as wiring in a simple .59 cent bridge rectifier and run the engine with and without load and carefully examine its performance and amp draws…..get the amp draws down in the dirt with smooth performance with a rectifier and you can remove that variable when it comes time to upgrade …..

Pat

@harmonyards posted:

No.1 rule before doing an upgrade is making sure the engine/engines you’re upgrading are 100% mechanically sound before adding very expensive electronics….

Excellent advice, and something I will do during my next upgrade. However, I did not perform this upgrade. My friend told me he paid a local vendor and waited a very long time to receive the engine.  He brought it to run on my layout, but in reality, I think he brought it to me because he knew I would want to fix it. This included replacing the motor swivel plates which were severely warped.

The first short involved a pinched LED wire that occurred without my even removing the shell.  The second occurred when a wire from a smoke unit motor came loose and grounded. This in turn blew the power chip.  After this, I resolded & tested absolutely every connection!

@gunrunnerjohn posted:

Nope, you don't need the slave board, just see if the master has the same issue in a different engine.

I tested the Veranda board in a different PS3 upgrade engine - same effect. The caps get so hot you can't touch them.

I don't know what happened to that board, but clearly it'll need some attention, and there's no certainty that it can ever be made right.

Those Caps support audio amp as I mentioned.  One end to DC ground, other to pins off audio amp.  When I replaced power supply the board functioned fine and audio worked.  If those components are the ones getting hot I would suspect you could read a low resistance.  You could try swapping components from another dead PS-3 board.

But given that you're going to park the engine as if it is dead and not use the board, why not run it and see that all the other functions including slave board work.  It may fail it may not.  If it does fail, you're back to parking the engine.  Which is where you are now.  At least you should be able to test the engine.  G

I could run to failure but it is not my engine and would prefer to return it without this being a concern. I also do not have a dead PS 3 board for part swaps but would not be afraid to replace components if I knew what to buy.

There are other caps running hot, but would have to verify each.

I'm sure multiple ceramic caps have not all failed unless they were abused, so something else is afoot in that board.  I might buy one, or even two failing, but "multiple" takes it out of the realm of possibility, at least IMO.

Do the techs have replacement boards available?  I have a few from the latest shipment, but those are reserved for my own projects.

Replacement boards are rare, they haven't been available for some time.

@gunrunnerjohn posted:

I'm sure multiple ceramic caps have not all failed unless they were abused, so something else is afoot in that board.  I might buy one, or even two failing, but "multiple" takes it out of the realm of possibility, at least IMO.

I've inadvertently blown an audio amp or two, never a power amp. Would that have caused these caps to short?  Seems strange.

Thank you for your guidance BTW

Truthfully, I can't imagine anything cooking those caps but excess voltage or excess soldering heat.  I've used ten's of thousands of those over the years, and I don't remember ever having a bad one.  Having multiple caps fail on one board has to be a unique circumstance.

You do not know if the caps are over heated or some short in the traces that is generating the heat.  Did you measure cap resistance?  If they are high resistance I do not think they are the issue.  The owner needs to understand the issue and give concurrence.  Based on all the mods done and potential issues, I would still run it with the repaired board before I put a new board it.  G

  WHY ?

  They can announce 2-3 new engines a week but they can't provide replacement boards.

@CHOO-CHOO MIKE posted:

  WHY ?

  They can announce 2-3 new engines a week but they can't provide replacement boards.

Every board they get goes towards a new engine, I don't think they get many. It's even possible that MTH has had to cancel or postpone new announcements due to chip shortages.

Where I work, we have a project on hold until the electronics arrive. Ordered them last March (about 250 units) and we expect arrival in November or December.

G, I would have no issue running it to failure if there was no possibility of shell damage.  This board is stacked on top of a slave board, hot side facing up.  I have Kapton tape and could possibly use that as a shield. Not sure of its effectiveness, and you are correct - the owner gets to make this decision.

BTW; I tried to measure resistance across the small caps and did not get a reading. However, I was able to measure a resistance across the components circled in yellow. Not sure if this is relevant.

Those are probably chokes, so they would indeed have continuity.