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Electronics => Repair => Topic started by: ballsystemlord on June 20, 2023, 03:34:25 am

Title: AMM Simpson 260 doesn't look at all like repair videos or docs.
Post by: ballsystemlord on June 20, 2023, 03:34:25 am
Hello,
I'm trying to repair a Simpson 260 AMM. It's a hand-me-down from my late grandfather who was an EE. The AMM accepts 5 batteries, 4 AA and one D cell. It suffers from corrosion damage. Unfortunately, all the repair docs and videos I've been able to dig up on this model show it having a PCB for all the components whereas mine looks like the components are embedded into the bakelite.

My need is to remove the bluish buildup after the AA batteries that my Grandfather placed into it leaked. So far, I managed to get a lot of the corrosion off with just a dremel and a straight SS brush attachment.

The camera will not focus, but you can see inside the blue reflecting from deep inside of the AMM. And my dremel will not fit into that area.
Additionally, one of the battery negative terminals has become frozen as a result of exposure to the acid. If you know how to free it up, I would appreciate the advise. I intended to just leave it the way that it is and use a small conductive aluminum piece as a spacer, to hold the AA cell in place.

Any ideas how to get the corrosion off so that this AMM will work?

Thanks!

PS: I removed all the screws and nuts I can see, but the bakelite piece will not budge and I am unwilling to force it.
PPS: I can post larger pictures if you want bigger ones.
Title: Re: AMM Simpson 260 doesn't look at all like repair videos or docs.
Post by: ballsystemlord on June 20, 2023, 11:52:11 pm
Just a thought, could it be that this meter is a pre-production model or something? It's hand scored, series #13 and I know my Grandfather had access to a lot of pre-production equipment from a variety of manufacturers.
Title: Re: AMM Simpson 260 doesn't look at all like repair videos or docs.
Post by: mzacharias on June 21, 2023, 12:41:43 pm
Looks like a 260 Series 2 to me.

Go to simpson260.com for manuals, etc. For some reason the page takes forever to load. Be patient.
Title: Re: AMM Simpson 260 doesn't look at all like repair videos or docs.
Post by: ballsystemlord on June 22, 2023, 12:24:27 am
That's the one, thanks!
I'll post updates as I get it repaired.
Title: Re: AMM Simpson 260 doesn't look at all like repair videos or docs.
Post by: AUBI on July 18, 2023, 07:54:49 am
For removing rust, you may need this kind brush: https://www.aubibrush.com/mini-hand-scratch-knife-brush (https://www.aubibrush.com/mini-hand-scratch-knife-brush)
Title: Re: AMM Simpson 260 doesn't look at all like repair videos or docs.
Post by: Runco990 on July 18, 2023, 03:39:45 pm
Use white Vinegar to remove battery corrosion safely, rinse well.
Title: Re: AMM Simpson 260 doesn't look at all like repair videos or docs.
Post by: Stray Electron on July 19, 2023, 01:48:45 am
Quote from: Runco990 on July 18, 2023, 03:39:45 pm
Use white Vinegar to remove battery corrosion safely, rinse well.

   CLR and LimeAway also work well for taking off battery corrosion.