Radio Shack (Micronta) multitester model no. 22-216 - Page 1
Forum section: electronics / repair

author: EritheBla
author_rank: Newbie
timestamp: March 23, 2015, 10:10:10 pm
content: Hi Guys,Thanks for a great site with tons of info; did a search for my model, nothing from what I could tell.I have a Radio Shack analog multitester, model 22-216. It is a good unit and has served me well these years. I'm not an electrician; more of a handyman who does a lot of different repairs and such.The other day I went to do a voltage check. Instead I pulled the brain fart of the year (for me so far) and had the setting to "current." I know better, was just not paying attention () When the terminals hit the (110 volts ac) power source, I heard the pop and saw the white flash.I have included two photos, front and rear of unit. Notice the discoloration in the lower right corner of the reverse view.I know I can always get a new tester, but this unit has sentimental value, and there aren't many of these around (I've looked). If I can fix it I will try, If not, oh well, them's the breaks.Any ideas? Is there a service manual for this unit? Anyone run into this situation and do a fix? I suppose I could farm it out to get repaired ($$$, I know); any ideas on ballpark figures for a repair like this? I know it's a lower-end unit, but it might be worth it to get an estimate.Just throwing some ideas out there to see what I can do.Anything would be appreciated.Thanks!e

author: bithead9
author_rank: Contributor
timestamp: March 23, 2015, 10:17:38 pm
content: I'd check that FUSE under the red tape - just jump it to see if it works. Just do not plug in the mains again to test

author: bithead9
author_rank: Contributor
timestamp: March 23, 2015, 10:18:32 pm
content: LOOKS like they give you a SPARE near the battery too! NICE.

author: EritheBla
author_rank: Newbie
timestamp: March 24, 2015, 01:12:56 am
content: It showed life, but the battery test function is out. If the fuse blows, are all functions disabled? I will need to get further in and look on the other side of the board. The red range light (3 volt range) still comes on… I'm thinking this one goes beyond the fuse...Im a newbie at diagnosing (let alone repairing) circuitry like this, but this old(er) dog may be able to learn a few new tricks.

author: mzacharias
author_rank: Frequent Contributor
timestamp: March 24, 2015, 01:15:23 am
content: I acquired a 216 that had a blown foil run associated with that fuse. Just a thought...

author: IanB
author_rank: Super Contributor
timestamp: March 24, 2015, 01:37:05 am
content: It is a tough test for a meter to survive connection to the mains on a current range. Since an ideal ammeter has no resistance to current flow, connecting such a meter to a supply with an unlimited ability to supply current is like putting a match to a pile of gunpowder. There is going to be a bang. The only question is how big the bang will be. Poor meterThe first and simplest thing to do is to trace the path between the two input jacks inside the meter. You should find the path goes through a current shunt (that may look like a coil of wire), through the fuse, and through some circuit tracks on the PCB. Check all of these for damage.If the fuse blows before anything else suffers damage, then only the current range will be out. The voltage ranges may still work. Unfortunately, putting mains through the current shunt (putting 100's of amps where only an amp or so is meant to go) may have done a number on the more sensitive parts of the meter. In the worst case it may have damaged the meter coil, in which case the meter has probably breathed its last.

author: EritheBla
author_rank: Newbie
timestamp: April 09, 2015, 10:09:32 pm
content: Hey guys,I took a chance and had Galco take a look at it... Free estimate. They said it was too far gone, the damage was too extensive..Dang, if they can't fix it, it's RIP.Oh, well, it's off to eBay, or the local garage sales or who knows where?In the meantime, I've picked up an el-cheapo HF digital. Not a bad little meter, and the price was right. It's already served me well. I'll find an analog meter eventually.Thanks for your views, and responses, and suggestions.

author: mzacharias
author_rank: Frequent Contributor
timestamp: April 09, 2015, 10:33:43 pm
content: Quote from: EritheBla on April 09, 2015, 10:09:32 pmIf you're in the U.S. I could probably sell mine. It's in good shape and reasonably accurate. Going to have to unload some meters soon, anyway.

author: retiredcaps
author_rank: Super Contributor
timestamp: April 09, 2015, 11:35:51 pm
content: Mark's 22-216 video is here.

author: cncjerry
author_rank: Unknown
timestamp: April 10, 2015, 06:29:20 am
content: I think you are giving up way too easily! Come on, be a man, put some spine into it! Go out and purchase $1k in test equipment and repair that ancient meter. It was meters like that which helped put a man on the moon!All kidding aside, replace the fuse and look around for burned traces or blown resistors. Yes, measuring house current in parallel is a bad idea but it might not be that bad. Where are you located? If you are in California near SF I'll fix it for free (though the two way shipping alone will make it uneco to repair)