Hallo @Carsten K.
Richard von Dolby London hat mir folgendes geschrieben:
Yes, unfortunately the media block options with a Series 1 projector become increasingly limited as the Cat 862 reaches its end of life. The good news, however, is that in my 10 years at Dolby, the only Cat 862s I've ever seen due to battery drain and certificate loss have been the ones that have been without power for more than a year as long as the board is occasionally charged and used - and I would say if the system is stored long term and has 24 hours of power every 4 to 6 months, it should continue to run indefinitely.
The batteries you sent the picture of aren't the only backup power on the board. These are actually the secondary cells that will only be put into operation if the primary cells fail. As you can see, these secondary cells are standard 3 volt lithium button cell batteries. The primary cells are the other two disc shapes you can see on the chalkboard. These are not batteries, but supercapacitors that are charged while the server is running and when fully charged (which, since capacitors are fast), this charging takes at least 6 months when the server is turned off Typically, the lithium batteries are never actually used, and since they are used as secondary backup batteries, they run out of power, which ultimately can happen due to the natural discharge pattern of a lithium battery, as long as the supercapacitor remains charged, never mind. I've never seen a super capacitor fail or even lose charge capacity, so these should never need to be replaced.
It would be interesting to measure the voltage coming from the lithium cells. You can do this by placing a voltmeter between the top of the cell and the test points. If these are close to 3 V or not below 2.7 volts, the batteries are still good. Unfortunately, these batteries are permanently attached to the circuit board and therefore cannot be easily removed and replaced. I never recommended desoldering and replacing these batteries just because it wasn't necessary before and because the board is multi-layered I would hesitate to do this myself, but I would say even if the batteries are below 2.7 V: As long as the device remains in operation regularly and does not remain without power for more than 4 months, in my opinion the risks of changing the battery outweigh the power failure due to the exhaustion of the super cap.