Vintage Synth Repair

Hi group,

I've got a TX-816 on my workbench. On startup, 4 units shows a code 4 (low battery). On two units, the battery have already been replaced and shows 3.16 V (pretty badly solded, though. I desolded them and put a battery holder; cleaner and easier to service).

The voltage is correctly driver up to the RAM.

However, on startup, the code 4 is still displayed, and the battery voltage (Utility -> Battery) is still 0 V.

Do I have to reset something to clear the error? I've seen on the user manual there is a kind of error acknowledgement through MIDI dump...

Thanks,
François

Update. Issues fixed: on one module, the battery was really finished. On the two other modules, the batteries were obviously replaced, but I suspect the job was done with a too hot soldering iron. Even if I could measure 3.3 V on the memories chips, there was a lack of continuity between D1 and the 10 MOhm resistor (damaged track?). A simple wire between the resistor and the positive fixed the issue. I also desolded the battery and put a battery holder (spacing slightly different though, but easy to modify with a pair of pliers).

--- In vintagesynthrepair@yahoogroups.com, "alesisfusion8hd" <babouche369@...> wrote:

>
> Hi group,
> 
> I've got a TX-816 on my workbench. On startup, 4 units shows a code 4 (low battery). On two units, the battery have already been replaced and shows 3.16 V (pretty badly solded, though. I desolded them and put a battery holder; cleaner and easier to service).
> 
> The voltage is correctly driver up to the RAM.
> 
> However, on startup, the code 4 is still displayed, and the battery voltage (Utility -> Battery) is still 0 V.
> 
> Do I have to reset something to clear the error? I've seen on the user manual there is a kind of error acknowledgement through MIDI dump...
> 
> Thanks,
> François
>