American pinball and Pinballstar make pinball great

Our PD-16 boards use standard, through-hole, TO-220 FETs (IRL540A). FETs can die if a coil is locked on; so we made them through-hole so they're easy to replace. Any logic upstream of the FET should only die if a serious power event happens (ie. short to high voltage). The rarity of that happening justifies the use of [less expensive to manufacture] SMD parts.

#259 5 years ago

GSS

gstellenberg

Quoted from vid1900:
Now, assuming the OP does not have a SMD rework station, how much will you guys charge to repair his blown board so he can have a spare on hand?

I see the word "pre-driver" being called out as the problem here, but I suspect that's just the wrong word being used. It's more than likely just the FET, which is through-hole. Any standard PCB repair person could swap one out in minutes. I highly recommend pinside user borygard for all of your circuit board repairs.

#311 5 years ago

GSS

gstellenberg

Quoted from LTG:
An electronic component failing could happen to any pinball manufacturer.

For sure, but that could also just be the symptom. Possible root causes:

- A weak transistor or other component (though in normal operation they usually either fail quickly or never at all)
- A bad crimp/solder connection
- A partially broken wire in the machine or trace on the board
- A screw or something shorted out the circuit momentarily
- Poor button alignment causing the flipper to re-energize repeated due to vibration
- Faulty coil
- Something in software that caused the coil to drive too hard

FETs can and do die sometimes, usually because of some other system event. The weirdest I've seen is when a single strand of coil wire bridged the gap to another lug. Luckily the coil was visible when it happened (because we were testing flipper assemblies). The strand of wire turned bright red and then disappeared, and it took out the FET on the driver board. Since the strand was gone, it never caused another problem. That's likely not the issue here because Houdini uses lugless coils.

Unless the problem happens again, we'll probably never know the root case.

#349 5 years ago

GSS

gstellenberg

Quoted from bobukcat:
let's use PD-8 and -16 PROC drivers as an example

We only have one coil driver board (PD-16) and one switch input board (SW-16). Making other variations, such as a PD-8 or various combinations of drivers and switches, wouldn't be much less expensive (because of the common circuitry), yet it would cause a whole host of issues for customers, techs, and manufacturers and defeat many of the reasons for using modular, easily replaceable boards.

#351 5 years ago

GSS

gstellenberg

Quoted from tadpole17:
hi Gerry,
board has been repaired by me.

Just replaced the FET and everything works again?

#355 5 years ago

GSS

gstellenberg

Quoted from bobukcat:
Any comment on availability of schematics for these boards?

A few bad apples in the industry ruined this for everybody. We started out by releasing the P-ROC schematics and had plans to release the FPGA code, but then a few people took advantage of our generosity and used our technical information to design us out. In one case, we spent months worth of man-hours helping a designer by essentially teaching him how to engineer a full machine around our boards, and then he designed out our boards. Lesson learned. While there are some wonderful people and businesses in this industry, there are also some that will do (and are doing) everything they can to take advantage of others without remorse or compensation.

All that said, the driver output stages on our PD-16 boards are very, very simple. Anybody with enough experience to understand a board schematic should have the ability to debug and repair a FET circuit without the schematic. If a board gets damaged beyond just the FET, the time it would take to debug and repair it isn't justified when replacements are relatively inexpensive. Our switch boards are $45, and our PD-16s are $85. We're not talking about $300 node boards here.

#358 5 years ago

GSS

gstellenberg

Quoted from bobukcat:
Punishing the whole class because of one bad student seems like the lazy was to deal with a problem, to use a metaphor (or is it simile, I don't do grammar) other than a cargument.

I feel like we bend over backwards to help the "whole class" while also taking a few precautions (resulting from learning the hard way) to give ourselves a chance of staying in business.