The Seiko SHC059P is more commonly known by it’s sawtooth nickname, so called because the bezels edge resembles a circular saw blade. I recently had one come in just needing a new battery so I removed the back to fit a new one. The existing battery was quite dusty with a big ball of fluff hanging off it, it must have been found down the back of the sofa and fitted!
With the battery removed there was some evidence of leakage, I’ve seen a lot worse but any leaking battery has the potential to cause damage.
The corrosion was cleaned and a new battery was fitted, this is where the problems started. The watch remained dead so I checked the circuit and found it wasn’t generating a pulse.
The sawtooth uses Seikos 7N36c movement and parts for these have been unavailable for some time, in fact replacement movements are unavailable. However, there is an alternative that can be used, Seikos VX33e. These are relatively inexpensive so it’s more cost effective to swap them out than to fault find and repair a dead one. A new movement was ordered and as you can see compared to the original it looks remarkably similar.
The calendar side is also very similar, the only fly in the ointment is the calendar wheels font is a lot smaller.
I thought this may look odd so I thought as they are so similar I thought I’d try swapping the wheels over even though the part numbers are different. With the wheels off the similarity continues.
And bingo, the wheels fit perfectly.
The dial and handset was refitted.
The movement recased and the seals silicone greased.
A pressure test was conducted, no problems there.
And there she is, completed. It’s sods law how a simple job like a new battery can turn out to be a lot more involved than you’d think.
You can see how it earned its nickname!