Greg007

I guess I got misunderstood, sorry for my English. I didn't mean that StringJunky didn't help me, just that there is nothing in the user manual about a crash at startup - Section 8 Troubleshooting. The spectrophotometer worked for several years and it happened once that it crashed (for no apparent reason), but after switching it on / off several times, it started working. Now it freezes always.

Thank you for the link, but this is the user's manual. There are no helpful comments for this situation.

This is my first post, I heartily treat all users, :-) Spectrophotometr Hach DR 3900 - hangs on startup. I do not have a service manual - maybe someone has? I replaced the lithium battery on PCB and pressed the restart button - no change. Any suggestions? Regards