Expression 3 - Lost Sub Data

Did some searching and reckon it might be a battery (CR2477 form an earlier post) But just in case it could be something else I'm going over symptoms here.

1 The board was turned on to find all submaster lights off and contents gone!

2 A backup disk was read in but this did not inhabit the Subs.

3 The system clock is showing correct Date, Time etc.

4 A Sub was programmed and the board turned off for just a minute or so. When it came back up that sub WAS inhabited (green light). Good news. But

5 After leaving off for 5 minutes the subs were again gone on startup.

Sooooooooooo!, No master clock problem but one of a failure to hold on to or load Sub data. (probably cues as well but didn't test them)

The bad news; this board is probably about 20 years old!

Parents
  • Earlier Expression 3's used two super capacitors to retain SRAM data. Newer and retrofitted Expression 3's use the CR2477 battery for SRAM data.

    It sounds like this particular Expression 3 may have supercaps for the memory, instead of a battery. To check, open the console, and unscrew the five screws from the CPU tray in the middle. On the PCB edge closest to you, there will be either two nickel-sized round components next to each other, or a battery.

    If it does have supercaps, they're likely failing. If it has a battery, you can check the voltage with a multimeter. As long as the voltage is above 2.2V, the SRAM will retain memory. A good battery will be about 3.0V.

    If the console has a good battery, then there may be a deeper issue--possibly a failing voltage control chip or failing SRAM. If the console has supercaps, it can be retrofitted with a battery.

    The good news is, we can still fix an old Expression 3, and retrofit it with a battery if it has supercaps.

Reply
  • Earlier Expression 3's used two super capacitors to retain SRAM data. Newer and retrofitted Expression 3's use the CR2477 battery for SRAM data.

    It sounds like this particular Expression 3 may have supercaps for the memory, instead of a battery. To check, open the console, and unscrew the five screws from the CPU tray in the middle. On the PCB edge closest to you, there will be either two nickel-sized round components next to each other, or a battery.

    If it does have supercaps, they're likely failing. If it has a battery, you can check the voltage with a multimeter. As long as the voltage is above 2.2V, the SRAM will retain memory. A good battery will be about 3.0V.

    If the console has a good battery, then there may be a deeper issue--possibly a failing voltage control chip or failing SRAM. If the console has supercaps, it can be retrofitted with a battery.

    The good news is, we can still fix an old Expression 3, and retrofit it with a battery if it has supercaps.

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