Craftsman Pro 81079 amp meter broken (REPAIRED) - Page 1
Forum section: electronics / repair

author: raqumup
author_rank: Newbie
timestamp: July 04, 2019, 03:16:48 pm
content: so i'm the Shop Foreman at a Volkswagen Dealer and I am teaching some new techs. i had instructed one of them on how to do a draw test on a car and he managed to put my meter across the battery. This is my first meter i bought back in the early 2000's and i love this meter. i know its not an expensive one but it works well and i like it. i really want to try and fix it, not necessarily fix it myself, ill pay to get it fixed if someone would like to fix it for me. anyway, i have put a new fuse in it, no help. i have put my leads on another meter and they work with no issues. i have double checked the probe connections to the cables are not the issue and the main solder joints to the probe connections are good. so as far as i can tell he damaged one or more components on the boards. i have removed the boards completely from the meter and i don't see and visibly burnt or damaged parts of the board. does anyone have any tests i can do to try and figure out the issue? or anyone know any electronic Gurus that like to play with this type of stuff and might be able to fix it??? as i said i will pay to get it fixed. any assistance would be greatly appreciated.Thank you in advance. note, the rest of the meter works just fine.Troy McWhirter

author: coromonadalix
author_rank: Super Contributor
timestamp: July 04, 2019, 08:24:19 pm
content: Please show us some photos

author: raqumup
author_rank: Newbie
timestamp: July 07, 2019, 06:13:13 pm
content: sorry it took so long to get the pictures. does anyone happen to know where i might find schematics for a meter like this? i think i was also mistaken about the age of this meter, its made by EXTECH and its a re badged EX470A. i guess this was produced from 2013-2016. but i still would like to try and fix it myself. if i can't that is OK, maybe i can learn something along the way.thanks for the helpTroy

author: coromonadalix
author_rank: Super Contributor
timestamp: July 07, 2019, 06:20:09 pm
content: seems an Extech EX400 series rebrandedThe hint is ex470b on the pcb470b model specshttp://www.extech.com/display/?id=14831

author: tunk
author_rank: Super Contributor
timestamp: July 07, 2019, 07:25:02 pm
content: The photo is a bit unclear, but it could be that the current shunt isgone as well (the "vertical" solid copper wire to the right of the fuse).If you have another meter you could check for continuity.

author: raqumup
author_rank: Newbie
timestamp: July 07, 2019, 07:35:02 pm
content: yea, i had said that in my post, but thanks for your input.

author: raqumup
author_rank: Newbie
timestamp: July 07, 2019, 07:45:28 pm
content: so i finally was able to sir down and spend some time actually looking at the meter and i found the problem. the spring clips that hold the 20A fuse were loose and not holding the fuse tight enough. i have corrected this and tested it, the meter works just fine. thanks for your input guys, i really appreciate it.

author: coromonadalix
author_rank: Super Contributor
timestamp: July 07, 2019, 08:08:52 pm
content: glad it worked, you can modify your first post title to say " repaired "

author: raqumup
author_rank: Newbie
timestamp: July 08, 2019, 06:05:17 pm
content: awesome, thanks. i was wondering how i should do that