This is a telemeter from a vending machine. It is what communicated over cellular for credit card payment. This is now the third one I've had quit working the exact same way. Just dies. No indication, nothing. Blank screen as if it lost power. All 3 had the same failure. And as a matter of fact all three were just shortly out of warranty. The first two failed and I was able to buy a remanufactured exchange units. This time I contacted them and they no longer offer remanufactured units. Some chip shortage or something blah blah blah. They wont even take mine to rebuild. Only option is to buy the newest version which is not cheap. (of course there are plenty of chips for them). Through the grapevine I found the parent company who manufactures these units. I have a call in with them to see if they can rebuild it or even just provide a schematic. So far have not heard back. And I'm not hopeful.
Anyway, can any trained professionals look at the pics and maybe point me towards any common failure points?
I poked around briefly with my ohmmeter. 34V DC enters, goes through F2 which I assume is a SMD fuse? Then goes to D24 (left side) I have not connected it to my bench supply just yet to see if I'm getting voltage out of D24. I cannot seem to find the correct datasheet for D24. markings on chip show 909k, psc, D1156s (I think). Question though. The fuse F2(LF050?), Should that show 3.2ohm across it? Do SMD fuses go bad? Tonight if I have a chance I'll hook it up to my bench and try and trace the voltage. As to me it seems like an open in the voltage circuit.
Thanks for any help!
~Tim
Anyway, can any trained professionals look at the pics and maybe point me towards any common failure points?
I poked around briefly with my ohmmeter. 34V DC enters, goes through F2 which I assume is a SMD fuse? Then goes to D24 (left side) I have not connected it to my bench supply just yet to see if I'm getting voltage out of D24. I cannot seem to find the correct datasheet for D24. markings on chip show 909k, psc, D1156s (I think). Question though. The fuse F2(LF050?), Should that show 3.2ohm across it? Do SMD fuses go bad? Tonight if I have a chance I'll hook it up to my bench and try and trace the voltage. As to me it seems like an open in the voltage circuit.
Thanks for any help!
~Tim