My fried multimeter

[KeepItSimpleStupid]

Another case of "planned obsolesence"?

 

[mvs sarma]

DMMs with COB(chip on board )are irreparable, if the COB goes faulty. you can store it as set of other components for future salvaging.

 

[Ziddik]

good 'multimeter story' **broken link removed** but sadly there is not any secondary fuse in my fried meter! The proble must be i connected it to external powersupply! Alas!

 

[carbonzit]

So you never answered our earlier questions about why you were getting such short battery life with your meter.

I wonder if it's so cheap that it was never really "off", even if it was turned off. (I've used other cheap devices with this problem, where you'd have to actually remove the batteries if you didn't want them to run down.)

 

[Ziddik]

So you never answered our earlier questions about why you were getting such short battery life with your meter.

I wonder if it's so cheap that it was never really "off", even if it was turned off. (I've used other cheap devices with this problem, where you'd have to actually remove the batteries if you didn't want them to run down.)

dunno about it but its battery would be drain quickly, i must buy a cheap one

 

[Ziddik]

For 99% of typical applications, the cheap multimeters work fine. And if you blow one, it's not a big loss.

i remember another things that happended just before the meter fried! As i said i was using an external powersupply (LM317T adjustable supply) so when i connected the two probes to the output of 7805 the power indicator LED of the external powersupply became too bright! that means the voltage which i measure at the output of 7805 might be passed through the probes to the powersupply! Otherwise the LED wouldn't become bright! Any idea? It doesn't make any sense **broken link removed**

 

[mvs sarma]

Perhaps, we learn from mistakes .

 

[Ziddik]

Perhaps, we learn from mistakes .

we often lose something precious when learn from mistakes that made by ourselves..

Its a hard way to learn.. But sometimes it has to be..

 

[tvtech]

As a TV Tech...I STILL use analogue. No frying, no false readings from G2.

Not cheap Analogue/Digital. A YEW 100 KILO OHM per Volt Multimeter. Taut band instrument. That was is a major car accident round 13 years ago.
Original accuracy from 1% on DC Volts to still to around 2% after the accident.

After all these years. There are Techs that only use Digital meters......to try and repair TV's. Hit and miss affair. Faulty junctions you will NEVER find with a Digital Meter.

FWIW....Analogue meters LOAD a transistor junction when forward biased like a DMM canno't do. Ever. I don't have to explain it here. Done it before. Please read my previous posts.

My take:

1. New design...accurate Voltage measurements necessary. I use my old Fluke 77. Great meter after all these years.

2. Repairing electronics/TV's....the old Analogue YEW. It never lies. Ever.

Cheers

 

[Reloadron]

Back at post #19 I provided an image showing how to connect a meter to measure voltage and current. Exactly how were you using this poor meter when it committed suicide? You do not measure current by placing the probes across the source.

Ron

 

[Shyamal]

Nice posting

 

[Ziddik]

Nice posting

what do you mean with nice postings?

 

[squishy36]

Here's a tip for folks somewhat new to electronics and multimeters: buy one that has separate jacks for current inputs and voltage/resistance measurements. The reason is that everyone sooner or later connects an ammeter to a voltage source. If the current/voltage/resistance inputs are all the same, sooner or later you'll have the probes on a voltage source and turn the mode knob, passing through the ammeter mode. At the least, you blow the fuses. With industrial meters like the Flukes where the fuses can cost $5 to $15 each, you learn not to do this pretty quickly.

Yes, it can sometimes be a pain to have to yank that lead out of one jack and put it into another, but it's a deliberate operation and makes you a bit more careful. Meters like the Flukes will also complain audibly if you have leads plugged into ammeter jacks and the meter set to a non-ammeter mode.

 

[PatM]

<snip>
My take:

1. New design...accurate Voltage measurements necessary. I use my old Fluke 77. Great meter after all these years.
<snip>
Cheers

My old Fluke 8060A is still going strong.
Fluke's are great meters

 

[tvtech]

My old Fluke 8060A is still going strong.
Fluke's are great meters

I agree absolutely. Not for repairs though. There you need Analogue to tell you the truth 100% of the time with Semiconductor junctions.

My take over the last 20 years or so. I have fixed many sets with faulty...not completely failed junctions on Transistors and Diodes that have been missed by guys using Digital meters only.

Find the faulty component. Test it on the YEW. Give the the component to the Digital guy. Ask him to test it. Fine he says.

Replace component. Set is fixed.

Every time

Cheers

 

[Reloadron]

My old Fluke 8060A is still going strong.
Fluke's are great meters

I still have a pair of them lying around. Really a great meter and those are over 20 years old. While I do like the Fluke line, Agilent is no slouch and making some real nice DMMs. There was just an article posted in these forums on a new Agilent DMM, pretty sweet DMM.

Ron

 

[debe]

I agree absolutely. Not for repairs though. There you need Analogue to tell you the truth 100% of the time with Semiconductor junctions.

My take over the last 20 years or so. I have fixed many sets with faulty...not completely failed junctions on Transistors and Diodes that have been missed by guys using Digital meters only.

Find the faulty component. Test it on the YEW. Give the the component to the Digital guy. Ask him to test it. Fine he says.

Replace component. Set is fixed.

Every time

Cheers

Also found checking HV switching transistors that are leaky will only show up using a Megger meter.