Blew up my DMM!

[Eric H]

I got to close to an exposed flyback terminal while trying to check B+ and it went sizzle.

It was just a split second but after that the Volts readings were out to lunch, reading way high, the Ohms seems to be OK though.

Opening it up revealed three fried resistors, how did they get so fried when it was only a momentary zap?

I also noticed some carbon tracks between two of the segments of the rotary switch, I was able to clean that off and I think it's OK, my main problem is I don't know what value those resistors should be.

I know it's a long shot but does anyone have the service manual or another meter like this they could look at and see?

It's a Blue Point brand, that's Snap-On Tools lower cost line, though it wasn't particularly cheap since Snap-On charges through the nose for everything.
It's been a good meter though, like to fix it since I can't really afford another one right now.

I have a couple other Meters I can use but they aren't as easy to use.
I broke out an ancient but top notch Military VTVM to use tonight, it seems accurate which is amazing since the last person to use it was probably lived in the town of Bedrock.

[snelson903]

wow that is a oldie,im gilty off blowing my favorite meter in the past .getting in a hurry did mine in, and its back when they costed more then todays meters.

[DavGoodlin]

Yes, I too have taken more than a few voltage readings with my Triplett 2202 (similar to yours) on the "amp" ranges.
pooffft

It happens about 1x a year. Now there is an automotive fuseholder in it. "fortunately I keep my feathers numbered....

[Eric H]

Originally Posted by DavGoodlin

fortunately I keep my feathers numbered....

That's a quote from Foghorn Leghorn if I remember right?

[bob91343]

I recommend buying a Harbor Freight Chinese DMM. They are less than $10 most of the time and you can afford a few of them. I have about four and use them often. They have 1 Megohm input impedance on Volts, adequate for most measurements. They also measure a few other parameters. The test leads and battery alone are worth the price.

When you measure high voltage, there are some fusible resistors that usually go; a good meter setup only burns one of them out and replacement is a piece of cake. I had to do that once with my Fluke 73.

[Electronic M]

I've cooked the ohms function on several meters now(never measure voltage in ohms mode)....I cook about one a year, but have been known to go on a spree and kill more than one a day when I'm having a moment of heightened stupidity.

[Eric H]

I was looking at Harbor Freight, seems that have a pretty decent looking meter for about $19, I'll probably give it a try.

[wkand]

Hi Eric:

As a self-confessed Harbor Freight junkie, (and proud of it!!) I have many of the smaller meters (Item 90899 - old number) that go for as low as $2.99 with a coupon. Less often they are free with a purchase. They are all fine. The only problem I have had is with the cheap test leads. Even those can be repaired. They are pretty rugged as well, and I've got one in every toolbox, glove box of both vehicles, every room in the house, etc. As others have said input impedance is 1 Meg ohm, not 11 like better meters.

The $20 meter you are referring to has a lot of features for the price, and gets good reviews except for the display module which is designed to tilt out for easy viewing, but apparently is not very secure, as several customers have commented on breakage of the display connections after only a few flexings. HFT does return defective products to their research facility in your neck of the palm treed woods, repairs them, resells them, and notes the defect for future design improvements, so its possible that they have fixed the underlying issue. I have no personal experience with these meters.

HFT is great on returns if you keep the receipt, and our Sunday paper has a color ad for them every week as do many home improvement and car magazines for 20% coupons, etc.

[dieseljeep]

Regarding inexpensive digital meters, The last one I bought, was from Sears.
They really aren't that much more expensive and they have a lot better quality test leads included.
One Craftsman unit I have, has frequency, capacitance and true RMS AC range.
I remember, it wasn't that expensive, on sale.

[ziggy7]

Either Snap-On or a local Snap-On dealer can probably provide a manual. I'd start at Snap-On.com.

[Geist]

Hi All;
I have had good luck with Radio Shack.. Even though I have to replace the unit about every 3 to 5 years, as the voltage range seems to mess up after awhile.. But, they have been good for me.. I guess it depends on what you are looking for and what kind of quality you want..
THANK YOU Marty

[Reece]

++ on Harbor Freight cheapies: I have a double handful of the things. If you fry one fuggitaboutit. They are plenty accurate enough for radio/tv work. Test them by plugging them all into the same source and they'll be really close to each other. Very handy for monitoring three or four parameters at the same time.

[Jeffhs]

I have a Velleman (Chinese/Japanese (?) off brand) DMM I purchased from Amateur Electronic Supply in Milwaukee several years ago. It still works well, but I make certain what position the range switch is on before I connect the test probes. I charred some parts and melted the casing of the zero adjust pot in a cheap Radio Shack analog meter I had in the 1970s when I neglected to change the range setting (on this meter one changed scales and ranges by connecting the probes to different jacks on the front of the meter -- that's how cheap the thing was) when trying to measure the line voltage at one outlet in an outlet box in my workshop at the time. I knew I was in trouble when I saw a thin plume of smoke rising from the ohms range jack. The meter, amazingly, still worked well for some years afterward.

That taught me a lesson I knew I'd never forget, and now I make absolutely certain my meter isn't on ohms or the wrong voltage range for the voltage I am trying to measure. I realize these meters are fused against mistakes and/or accidents, but I am sure it is still possible to damage the instrument beyond repair if the voltage being measured is far too high for the range you selected -- say trying to measure B+ voltage on a radio/TV tube with your meter set (for example) for 1.5 volts full scale. Such a severe overload, of course, will blow the fuse, but probably not before damaging other parts of the instrument first, as the fuses used in these meters do not, as a rule, act quickly enough to prevent damage to sensitive components, especially when the meter is severely overloaded. With today's solid-state DMMs, such an overload would probably ruin the instrument in no time flat. There is one range on my DMM that is not fused; of course, if this is overloaded, the meter will be destroyed in an instant.

I wouldn't use a DMM to measure voltages near the HV plant in a television set, the reason being it is far too easy to accidentally brush against the 2nd-anode connector of the CRT or other parts of the HV system with a test probe; this, as one other person here has noted, will put the meter out of commission in the blink of an eye. The meter's internal fuse(s) may blow at this time, but by then it is usually too late; the damage may have already been done.