Check fuses. Possibly, you popped a fuse when it sparked.
However, since you still have a red light on dash, it's probably not the main fuse.
Check the voltage directly at starter while starter button is engaged, see if power is making it from the battery to the starter. Let us know the results.
See:
that is another good post.
It absolutely pains me to admit it, but when I did maintenance work on my Triumph T595 about a year ago, I was interrupted just as I went to put the leads on. I dropped a bolt down under the battery ; had to remove it to retrieve said bolt; and then put the battery back in. It’s a real pain and quite difficult : Somewhat miffed and not fully focused- this was the VERY last task-I put it back in.
I physically put it in backwards and had a reverse polarity!!( as an Electrician working with 240 and 415vac, THAT is something I HAVE NEVER done. NEVER. It’s always ‘take a step back and reassess when a step or process is broken etc’. Always. We work live with lethal voltages and people have been killed by idiots reversing switchboard polarity. Much of my refresher training every 6 months was focused on Polarity and the utter importance of getting it right.
Yet I did it on my bike.
My point is when I made the final connection ( the neutral or the black or the return or as some call it; the earth) I got a spark.
I recall thinking that was strange- but thought no more of it. I was terrified I’d blown the ECU!
To my everlasting gratitude towards some nameless Triumph Engineer, there was a fuse in series with the ECU and boy, did I almost weep when I found it blown.
THIS was the only one which went pop. Not the Main one.
Sorry for the novella, but just recheck every thing you did once again.
BTW: try running some wires from the correct battery terminals to the correct terminals on the starter solenoid. That will tell you the battery is ok: and maybe the solenoid terminals are high resistance; or maybe the starter button could be .
Can’t hurt to check.