Juno 106 CPU diodes

Hi everyone, I’m new here.

I recently bought a Juno 106 that I’m restoring (with the help of some parts I bought from Syntaur). I need to replace diodes D9 and D10 on the CPU board because the old battery exploded and corroded them. I couldn’t find a parts list in the service manual that’s circulated online, so I’m not sure what these diodes are.

Anyone know what type of diode D9 and D10 are?


It looks like they are both 1SS-133 diodes. You should be able to find them easily and cheaply.

Thanks! That’s what I saw on page 12 of the service manual, but I thought it was in reference to the diodes used on the module board.

The one thing that’s odd about the 1SS-133 is that it has a forward drop of 0.6V at 1mA, which feels like a lot considering the battery is only supplying 3V when fresh and is supposed to be replaced when down to 2.8V. So what I’m saying is that the supply voltage to the memory chip is 2.2V-2.4V, which seems kinda low.

I saw that note too, that all diodes on the module board are these, and it doesn’t mention the CPU board diodes. So I looked at an actual CPU board with a magnifier, and the diodes are the same ones. The only other normal diodes used in the 106 are on the power supply board, and they are noticeably different.

Wow! Thank you so much for going the extra mile to verify this! I really appreciate this!

You’re most welcome. Now make that Juno sing! It is very worthy of a good restoration.