I'm relating the following experience to show how information held by the US patent office helped me with a repair.
I recently repaired a Snap-On MT2261 timing light with an intermittent flash problem. As expected, Snap-On were not able to provide circuit diagrams, or a service manual. Their quoted price for a replacement circuit board was AU$900 which was more than the cost of a new unit.
However, I noticed that on the ratings sticker there was a reference to two US patent numbers. Sure enough, a search at the US patent office turned up a document
BTW, the fault was a 0.033uF HV ceramic cap connected to the low voltage winding of the trigger transformer. I replaced it with a 2kV pulse rated polypropylene cap. Because of its size, I had to relocate the replacement cap and attach it with 300V fly leads. Incidentally, the original ceramic cap tested OK on a cap meter. I confirmed that it was faulty by reinstalling it and reproducing the original problem.
PS. The following site provided the document in a more convenient format (a 20-page .pdf file), but required me to register (for free).
- Franc Zabkar