What if in a Presidential election (2)..........

[True Federalist (진정한 연방 주의자)]

The Republican and the Democrat have a tie in the Electoral College 269/269.

All the electors remain faithful and cast their electoral vote as their state voted.

The election of course goes to the House.

The House votes 25 state delegations for the Republican and 25 state delegations for the Democrat.

How is the tie in the House broken or what is the next step?

The precedent is well established.  Until and unless 26 States vote in favor of one or the other  (or possibly one of the three if a faithless elector voted for someone else to be President than he was supposed to) there is no President.

Over in the Senate, they'll need 51 Senators to chose who will be Vice-President and thus Acting President until the House chooses a President.  And I do mean 51 Senators, not 50 plus a VP.  The VP does not get to break this tie, and even if not all 100 Senators show up to vote, it still takes 51 to elect.

If neither a President or a Vice-President is chosen then under current succession law, whoever is Speaker on noon, January 20, becomes Acting President until one of the two elections is settled. (Assuming the Speaker is eligible, if not then it continues down the list until someone eligible is found.)

[True Federalist (진정한 연방 주의자)]

Incidentally, there is a chance for shenanigans in the Senate.  Unless a quorum of two-thirds of the Senators shows up, they can't vote for a Vice President.  So if the party that loses the popular vote wins a Senate majority, it is possible for the Senate minority to block his election by not showing up.

Much more difficult to pull that off in the House, since if even a single member from a State delegate shows up, he could cast that State's vote, so to pull a House boycott, a party would have to have the entirety of 17 delegations and yet have the other party control 26.

[True Federalist (진정한 연방 주의자)]

It would be more likely that the majority party in the House in such a situation would "temporarily" select a Speaker for just January 20 for the purpose of becoming Acting President and then the old Speaker would resume the Speakership.  The way the law is written, the Speaker (or the PPT) would have to give up their Congressional seat to become President, even if it just to be Acting President.  However, if both the Speaker and the PPT were to refuse to resign, possibly then the succession would fall to the Cabinet.  However, any election likely to put Pelosi back in as Speaker would see Obama easily reelected. So I'd say it's a sure bet that if we do get an electoral deadlock, the Republicans will find someone willing to give up their House seat to become Acting President.

(Note that a deadlocked Senate almost certainly means Inouye would remain PPT, as Biden would be able to break a tie on that vote when the 113th Senate organizes.  You'd need a 50-49 Republican Senate with one vacancy to get a Republican PPT and a Senate deadlocked over selecting a VP.)