Can you please clarify your question? When I enter the part # "P20N10L" in Marco's search box, it returns only one transistor part in stock. Not "a Huge List of Transistors".

Now, that one product page does show a large list of compatible transistors, including the part you are replacing, P20N10L. This is not unusual. Transistors, and other electronic components, carry a wide range of specifications, most of them maximum values such as voltage, current, temperature, etc. As long as the replacement part meets or exceeds those specifications, it should work the same.

As a general rule, I think you can trust Marco's product page. It says the part you're referencing above is a suitable replacement for the P20N10L you are replacing, so that's the one you should buy.

yes

i use the IRL540 all the time in stern boards.

Looks like this transistor has been replaced before. There may be an underlying problem somewhere else in the machine.

I use the IRL540 to replace P20N10L.

As for it's suitability for all of these other transistors... probably you would be OK.

A long time ago I read an essay about a technician who had a friend who said there are only two transistors, NPN, and PNP. The reason he believed that is because most electronic circuits at the time had very wide tolerances, and if a particular transistor had specifications that were WAY out of the original design specification... the circuit would generally work.

It's a LITTLE like that for general purpose output drivers, but you should be careful, and it helps if you really understand the circuit and it's application from an Electrical Engineering point of view, and you should understand the specifications (look up a 'Datasheet' for the parts involved) and know the differences between the two parts you are trying to substitute.

In general, you can substitute a cross-referenced transistor FOR a particular part. You can substitute a IRL540 for a 20N10L. You can substitute a IRL540 for a 12N10L.

But just because a 12N10L crosses to a IRL540 and a 20N10L crosses to an IRL540 doesn't mean that a 12N10L is the same as a 20N10L. Depending upon how the circuit is designed to work you MIGHT be able to put a 12N10L in place of a 20N10L, but it might fail early or just not work. Using a IRL540 for either of those parts will almost always work fine, because it is the cross reference for both of those parts.

IRL540 transistors are a common substitution part. I buy them 50 at a time from Mouser.

In your case, there has been PRIOR WORK.

A huge amount of problems you find in pinballs are because of PRIOR WORK by the technician who worked on the machine before you. The technician before you may not have had ideal working conditions, or the skills, or the right parts to do the job well.

'To really mess something up requires a technician.'

So I would immediately swap that part and it's questionable work with a known good replacement IRL540.

Let us know how this turns out!

The first thing to do is look at the schematic and see what the original transistor was and find direct replacements based on that. Plenty of data sheets out there to convert if there is not a direct replacement available.

Like Retail says above, I never trust what's there unless it's a row of the same part # and obvious.

He does great work, but probably overkill for one bad transistor if there isn't other evidence of issues on the board.

What coil does this control? That is likely where additional remediation is going to be if any.

Power Mosfets have some generic part numbers.

the first two digits are generally the continuous current rating in amps. 20N10L would be 20a part

The middle letter lets you know if it is a N or P channel, 20N10L would be a N channel. 20P10 would be P channel.

The last two digits are a voltage rating (drain to source) that you multiple by ten 20N10L would be a 100V. 20N06L would be a 60v part.

When the final suffix letter L is added on, it generally means it is a TTL logic level part. It fully turns on before 3vs on gate. There are still many parts without the L at the end that still turn on fully by 3v, but you would want to check the datasheet and the circuit board. When there is a 74LS chip going to the gate of the mosfet you must use a logic level part. When a 74HC chip drives the mosfet gate, it will likely swing all the way to 5v (gottlieb system 3) and you can use 5v level mosfets.

IRL540N is a common part number people like to use in pinball. It should be able to replace pretty much any type of N power mosfet used in pinball. I think IRL540N would be equivalent to a generic part number of something like 28N10L. If that even exists. 40N10L is also a good one.

https://www.arrow.com/en/products/irl540npbf/infineon-technologies-ag