I sent my chronos to Sam Timer for repairs when the display began to fade on some digits.
He failed to fix it after 3 months and sent back the clock in the same condition while charging $70.
I recommend you purchase a new clock.
I sent my Chronos to Sam Timer as well in September this year for repairs.
It took 2 months for them to repair it but I think the length of the repair time can be explained by the long postage wait times between the US and where I'm from (Australia.)
They did fully repair my Chronos chess clock, which I'm happy with.
I notice with some of the other posts saying that the Chronos is not the best chess clock.
They are probably right, Chronos is not the best but there are a few things I think they got right.
-solid metal outer shell
-Crystal LED display
-clicky (tactile) push buttons
I gave up on the Chronos over a decade ago! The Chronos is utter crap!
I currently use the ZMartFun II, but also still have an old DGT North American.
The numerous reasons why the Chronos is utter crap:
The Chronos is a horrible clock!