Triaxis Battery Drain Issues

Hi guys.

I recently bought a Triaxis v1 #175 and im having some battery issues.

When i got it the battery was completely dead so I changed it and within two weeks that one was also dead. I tried better batteries. Now on Energiser and i'm getting the same problem. A little over two weeks and the battery is completely flat.

I'm guessing that something in the backup section is playing up but i've never dealt with memory systems before but have built numerous amplifiers.

My guess was that C40 was to blame and was leaky. Upon opening it up to check i noticed that this is 470uf not the 100uf on the schematic.

However I can only find a v2 schematic so does anyone know if this cap value is correct? Everything else is exact to the V2 schamatic.

I tried a 100uf 25v cap and once again the battery is completely depleted.

Does anyone have any other ideas or has come across this issue before?

I love the preamp but this is not an ideal situation. I'm considering selling it with the fault listed and buying another as the local tech to me quoted me £100 minimum just to look at it but also said he hates working on Mesa products and would rather not.

Right guys i've been banging my head against this for ages now.

I replaced the entire backup circuit and it still did it.

So i thought i'd experiment a bit.

I got a FM16W08 NVRAM chip and a SOP28 to DIP28 adapter to match the form factor of the 6264BL that the Triaxis uses.

Installed this & removed the battery and hey presto no issues.

Should be good for 151 years now. Fingers crossed.