Northeast Electronics Corp. Model TTS-28 - Repair

I originally repaired this while talking to the folk at the EEVBlog. There’s a post about that here.

Just got a new multimeter. There is extremely little information about it online. So I will be doing this repair mostly blind.

Looks pretty decent. A little rust on the ohms adjustment pot in the bottom left. It seems like it takes 3 batteries, 2xAA and one 9V.

Here are the two 9 volt leads. They look modern?

Close up of the AA slot.

Hmmm, take a look at this picture from ebay which shows an included 9 volt battery. Definitely not modern. Is it axial?

Well this doesn't fit.

Nor does this.

So we will plug it up a different way for the moment and modify those leads later.

Set to Ohms and zeroed out.

Working as expected.

Maybe all it needed was a few new batteries. However the current setup won’t work long term. The battery leads need to be modernized.

Time to butcher a perfectly good 9 volt adapter.

You can see the slight size difference in the plugs that was giving me trouble.

All soldered back together, heat shrink tubing installed for safety and installed in its slot. It kinda fits…

The test probes that came with it don’t always make good contact. I’m not completely sure about the best way to clean/repair them.

You can see testing I did on this meter at this follow-up post.