user12: Over the past few years of tournament play, I've seen three games where the delay was not enabled on a digital clock.  In all of these cases, the clock was a Chronos set to display HH:MM until the last 10 minutes, when it would change to MM:SS.
In one game without the delay, I was playing white in a G/105 tournament.  I ran my time down from ~12 minutes to ~6 minutes, and my opponent had ~9 minutes.  On my next move, I noticed that the clock started right away and pointed it out to my opponent (we are actually the two TD's for the club, so we didn't really have anyone else to make the decision).  We agreed to turn on the delay at that point.
Now according to a strict interpretation of the rules, we're stuck without the delay because that's how we started the game.  I usually make sure that the delay is set in the first few moves, but I just didn't notice that the clock moved right from 105 to 104 when he started it at the beginning of the game instead of waiting 5 seconds.  So after that, the only time I could discover the oversight was when we got below 10 minutes. 
Is there a reasonable way to deal with this? Am I just out of luck if my opponent tries to pull a fast one in the future? Theoretically he could be penalized for unsportsmanlike behavior, but that seems extreme if it really was just an honest mistake.

user103: There is an article by Geurt Gijssen on Chess Cafe (4th question asked) that touches on the event that the clock's initial time control being incorrectly configured, but only noticed much later in the game.
He quotes the FIDE rules:

The Laws of Chess cannot cover all possible situations that may arise during a game, nor can they
  regulate all administrative questions. Where cases are not precisely regulated by an Article of the
  Laws, it should be possible to reach a correct decision by studying analogous situations, which are
  discussed in the Laws. The Laws assume that arbiters have the necessary competence, sound judgement
  and absolute objectivity. Too detailed a rule might deprive the arbiter of his freedom of judgement and
  thus prevent him from finding the solution to a problem dictated by fairness, logic and special factors.

Geurt responds:

I especially like the last part of the last sentence: a solution should be “dictated by fairness, logic and special
  factors.” With this in mind, I think it is quite unfair to change the time modus at the moment a player only has
  one second on his clock in such a way that he only has this one second left. Therefore, I see two possible
  solutions: Change the time mode after the first period; Change the time mode at the moment of the claim, but the player should be given a reasonable amount
  of time (at least one minute) for the remaining moves.  I prefer the second option.

In your situation, it sounds like a reasonable action to stop the clock and set the delay correctly.  As for other cases, it looks like it lies to the TD to determine a fair trade-off.

12: <p>Over the past few years of tournament play, I've seen three games where the delay was not enabled on a digital clock.  In all of these cases, the clock was a Chronos set to display HH:MM until the last 10 minutes, when it would change to MM:SS.</p>

<p>In one game without the delay, I was playing white in a G/105 tournament.  I ran my time down from ~12 minutes to ~6 minutes, and my opponent had ~9 minutes.  On my next move, I noticed that the clock started right away and pointed it out to my opponent (we are actually the two TD's for the club, so we didn't really have anyone else to make the decision).  We agreed to turn on the delay at that point.</p>

<p>Now according to a strict interpretation of the rules, we're stuck without the delay because that's how we started the game.  I usually make sure that the delay is set in the first few moves, but I just didn't notice that the clock moved right from 105 to 104 when he started it at the beginning of the game instead of waiting 5 seconds.  So after that, the only time I could discover the oversight was when we got below 10 minutes. </p>

<p>Is there a reasonable way to deal with this? Am I just out of luck if my opponent tries to pull a fast one in the future? Theoretically he could be penalized for unsportsmanlike behavior, but that seems extreme if it really was just an honest mistake.</p>
 103: <p>There is an <a href="http://www.chesscafe.com/text/geurt117.pdf">article</a> by Geurt Gijssen on Chess Cafe (4th question asked) that touches on the event that the clock's initial time control being incorrectly configured, but only noticed much later in the game.</p>

<p>He quotes the FIDE rules:</p>

<blockquote>
  <p>The Laws of Chess cannot cover all possible situations that may arise during a game, nor can they
  regulate all administrative questions. Where cases are not precisely regulated by an Article of the
  Laws, it should be possible to reach a correct decision by studying analogous situations, which are
  discussed in the Laws. The Laws assume that arbiters have the necessary competence, sound judgement
  and absolute objectivity. Too detailed a rule might deprive the arbiter of his freedom of judgement and
  thus prevent him from finding the solution to a problem dictated by fairness, logic and special factors.</p>
</blockquote>

<p>Geurt responds:</p>

<blockquote>
  <p>I especially like the last part of the last sentence: a solution should be “dictated by fairness, logic and special
  factors.” With this in mind, I think it is quite unfair to change the time modus at the moment a player only has
  one second on his clock in such a way that he only has this one second left. Therefore, I see two possible
  solutions: Change the time mode after the first period; Change the time mode at the moment of the claim, but the player should be given a reasonable amount
  of time (at least one minute) for the remaining moves.  I prefer the second option.</p>
</blockquote>

<p>In your situation, it sounds like a reasonable action to stop the clock and set the delay correctly.  As for other cases, it looks like it lies to the TD to determine a fair trade-off.</p>
