All functions have ceased to operate - the reset works fine but none of the buttons seem to function. this problem started all of a sudden, i assumed maybe a button was stuck but they all seem ok?

This watch appears to be a battery operated model from the details I can find. Self Winding watches tend to be a LOT more expensive and usually a Big brand name! Assuming the Chronograph is designed to work the two buttons are usually 'Start/Stop', (top button) and 'Reset', (bottom button). Try this.

-Press the top button once. The smaller dials should start moving.
-Press the top button again. The smaller dials should stop moving.
-Press the bottom button once. The dials should reset to zero. There is another function of the Reset button. You can 'Freeze' the chronograph display for things like lap times.

-Start the chronograph, (Top button once).
-Press the Reset button once, (Bottom button). The dials should stop. The chronograph is still running you have simply paused the display.
-Press the Reset button again. The dials should 'Jump' to the current position the timer is at.
-Press the Top button once to stop the chronograph. *Note* Some of the cheaper watches simply have the dials and buttons for the look of it and don't actually work.

Hopefully, this will help...

Lego Watches Manual Instruction:
There are 4 buttons on this lego watch case, Light button, Mode button, Stop button and Reset button, now I will show how to set the time easily!
1, Light Button: Press this button, the watch LCD light will display for 3-5 seconds;
2, How to use the stopwatches chronograph function?
Answer: When the lego watches in normal working condition, Press "Stop button" for 1 time, then the watch goes into the chronograph mode, then you can use "Stop button" and "Reset button" to operate this function.
3, How to set the alarm time?
Answer: When the lego watches in normal working condition, Press "Stop button" for 2 times, then the watch goes into the alarm mode, then you can use "Stop button" and "Reset button" to set the alarm time, also you can turn off or turn on the alarm function and chime on every hour function by the same operate.
4, How to set the right watch time, hour, minute, second, week, date, month, year?
Answer: When the lego watches in normal working condition, Press "Stop button" for 3 times, then the watch goes into the time setting mode, then you can use "Stop button" and "Reset button" to set the second, minute, hour, week, date, month and year.

This is all. So now please have a try to set your lego watches time!

I am having the same problem. The battery is fine, the seconds are ticking away, but none of the side buttons work. The light doesn't come on and nothing happens with any of the others either. The only thing that did work was pressing all four of the buttons simultaneously, which seemed to totally reset the watch. The problem is it reset but didn't fix the buttons. So now I can't even see the correct time anymore.

Instructions for setting an MSP74810W watch.

Press the "Mode." button three times (the "Mode" button is the one next to the lower left of the dial when facing it).The first time you press you'll see the ST, or stop watch function, the second time you'll see the AL, or alarm function, the third time you'll be back to the time of day function but the seconds will be flashing.

Change the flashing seconds digits to read 00 by pressing the "Start" button (the "Start" is the button next to the upper right of the dial when facing it).

-To advance from the flashing seconds' reading to the hour of the day's digit/digits you press the "Reset" button at the lower right of the dial,
-To advance from the flashing hour digit/digits to the minutes digit/digits you again press the "Reset" button,
-To advance from the flashing minutes digit/digits to the month's digit/digits you again press the "Reset" button,
-To advance from the flashing month's digit/digits
to the day of the month's digit/digits you press "Reset,"
To advance from the flashing day of the month's digit/digits to the day of the week's abbreviation you again press "Reset,"
-To advance from the flashing name of the week's abbreviation back to the seconds' of the minute you again press "Reset," and from there you can go through the cycle again.

While the hour of the day with its A[M] or P[M] designation, the minutes of the hour, the month of the year's number, the day of the month's number, or the abbreviation of the day of the week's name is flashing press the "Start" button once, repeatedly, or hold it down to advance the number or letters to their correct designations.

Once all designations are correct push "Mode" so that none of the numbers or letters are flashing. Your watch is now set.

The small bottom dial is seconds counter and there is no option to set or reset it as it is part of the main gear train - it just counts the seconds. Top right dial is 1/10 seconds counter and runs only when the chronograph function is engaged. One full circle indicates 1 second. Top left dial is 30 minutes counter and runs only when the chronograph function is engaged. One full circle indicates 30 minutes, two circles = 1 hour. The big centre seconds hand is actually Chronograph hand and runs only when the chrono function is engaged. So, the chronograph hand and two top dials works all together when chrono function is engaged. To start chrono: push upper button once. To stop chrono: push upper button again (once). To return all hands to zero: push lower button once. There is another option: if you already stopped chrono by pushing upper button, but want to continue counting without returning hands to zero, push the upper button once more and the counting will start from the point where it stopped. You can repeat this as many as you wish - it will count on and on, till you will stop it and reset to zero. Fine tuning of chrono hands can be made by pulling the crown half way out and while leaving in this position pushing and holding one of the push buttons (which one - depends on movement caliber). Watch has an tachymeter function as well (big inner ring). Learn how to use it by browsing through my Tips and Tricks- it is explained there. Rate me, please.

The S120 is now a fairly old watch. When the function buttons and heart rate cease to function this is generally an indicator that the battery needs to be replaced. The buttons themselves can also become worn out or weak of function, in either case you have a couple of options.

1) send in to a Polar Authorized Service center: This is very important, do not take to a normal watch shop. You need the watch properly resealed and handled correctly as well as you may need parts such as a button return spring they will not have. Plus there is a 90day warranty on Polar's repair. You will also need to send in your chest strap just to make sure that is still functioning properly. Battery repair about $15-, new buttons another $10ish, and a chest strap if needs replacing about $25 or $30-. $50-$60 total if everything needs work, but this is just an estimate.

2) buy a new watch unit. The RS100 (the current replacement) is about $100- and is easier to use with a better chest strap.

mcdevito75here, I'm sue I can help you set this digital watch,----4 buttons, 1=light, this should be just for the light built into the watch, 2=MODE this is the button you press to set the functions, press this button and see everything flashing 3= Start Stop this button should act as set after you press MODE it should also be to start the lap counter and 4= lap reset this should bring the lap counter back to zero or the seconds tick normally.---- press MODE see everything flashing, then press start stop to set functions, hour, minute etc, press MODE after you have set each function, hour, minute, etc. When done with all functions press mode again to bring the watch back to normal operation.

The stop watch buttons don't pull out. There are 2 pushbuttons. The upper one starts and stops the timing function and the lower button resets the timing function. The crown has three positions: 1st position is for winding, 2nd for date setting and 3d for time setting. Once things are set wind the watch in position one and it should run. If it does not take it to a watchmaker. You don't want to fool around with such a valuable watch.

Great watch! Operation should be pretty straight forward. The top button starts the chrono and stops it. The bottom button resets it. To calibrate the sweep arm into the right position pull the crown out to the first or second set position and press the start button until the sweep arm is in the start position you desire. This is typically 12:00 or 0.
If your chrono is not working then have the battery checked. If the battery has been recently replaced then make sure the watch doesn't need to be cleared.
I recommend you take this to a watch maker/technician who will be familiar with the service requirements of this model including resealing and pressure testing the watch to be sure it is sealed to its marked water resistance specifications.

Thanks!

I had this problem after the battery was replaced at a jewellers. It turns out they had used the wrong battery as it only lasted a week.