Craftsman 82139 DMM

[ca7922303]

Was working fine. Kid got ahold of it and tested a running automotive coil. Now will not read voltage or ohms.

[Enzo]

Open it up, see if one of the fuses has opened.

[J M Fahey]

Try that, but typical 200mA fuse only protects the low current scales (up to 200mA); nit Voltage ranges because they do not expect any current (except picoamperes).

I have lost many a meter to measuring plate voltage in output pentodes, so I now only measure center tap voltage, period.

Or measure through a 100k to 1M resistor.

But a car ignition coil has kilovolts level.

[g1]

Has 2 fuses, but both for current ranges (see page 18 of attached). Does it show any indication of being powered on at all?

[ca7922303]

Has 2 fuses, but both for current ranges (see page 18 of attached). Does it show any indication of being powered on at all?

Dont see anything attached?

[Enzo]

I see the attachment at the bottom of post #4 and it downloads for me.,

[ca7922303]

I see the attachment at the bottom of post #4 and it downloads for me.,

Still don't see it?

[g1]

You need to go into your user settings and change 'display mode' from 'latest activity' to 'posts'. It is under the 'accounts' tab, scroll down to 'conversation detail options' .
Then you will see attachments (I guess you haven't seen any up til now), and newest posts will be at the bottom rather than the top of the page.

[J M Fahey]

FWIW I can see it:
Shows like:

Attached Files

• craftsman 82139.pdf (988.9 KB, 0 views)

[ca7922303]

Has 2 fuses, but both for current ranges (see page 18 of attached). Does it show any indication of being powered on at all?

It powers on, but no resistance or voltage settings. Both fuses are 0.0 ohms and both batteries are 1.5v.

[ca7922303]

You need to go into your user settings and change 'display mode' from 'latest activity' to 'posts'. It is under the 'accounts' tab, scroll down to 'conversation detail options' .
Then you will see attachments (I guess you haven't seen any up til now), and newest posts will be at the bottom rather than the top of the page.

Thanks, made the changes, can see it now.

[ca7922303]

Where do I start?

[J M Fahey]

Not sure you, us, or even Craftsman can repair it.

Best case, if factory issues and within warranty they will replace it, but I guess itīs not the case any more.
Sorry.

[Mick Bailey]

I don't seem much input protection at all for over-voltage - looks to be just a single MOV. No isolation slots and no arc shields. As Juan says - automotive coils run at kilovolts and this is likely to have flashed across the unprotected PCB. You could try metering through the input circuitry to see what's shorted or open.

[g1]

You probably start by replacing it, and deciding whether the kid pays for the replacement or not.