Help !! My B&K 390 multimeter not able to measure AC and DC voltages after I replaced the battery.
Thanks.

 

Did you replace it again in case the battery was dead?

 

Always look for the obvious first. I've had test leads go bad simply out of the blue, fuses that stopped conducting after a simple bump, wires or components I've accidentally touched that were about to short out to something nearby.

Simply replacing the battery on a VOM shouldn't cause a problem.

Did I mention battery connections that get oxidized or 9V snaps that break internally? There are also some type batteries that don't mesh perfectly with the holders whereas the older one did.

 

Hi Tom66, Actually it was working fine initially. I thoght that it has been awhile since the original battery had not being replace in case it leaks. Display still seems to be clear. I measure the 9V battery fwith another meter and voltage shows about 7.9V so I replaced it.
That's when I notice it is not able to do voltage measurement as I try to measure the old battery again with this meter. I replace back the old battery and also a new 9V battery. Still same problem.
Ohms measurement seems to be ok.
Thanks for your assistance.

 

Always look for the obvious first. I've had test leads go bad simply out of the blue, fuses that stopped conducting after a simple bump, wires or components I've accidentally touched that were about to short out to something nearby.

Simply replacing the battery on a VOM shouldn't cause a problem.

Did I mention battery connections that get oxidized or 9V snaps that break internally? There are also some type batteries that don't mesh perfectly with the holders whereas the older one did.

Hi Marshallf3, The fuse and leads are working fine as the ohm measurement is working. No oxidation on the battery. The original have never being replaced, so I thought it's time to have a new one before it oxidises. I guess if something is working, don't mess around with it.
Thanks for your reply.

 

I still say it's something simple, get a bright light and a magnifying glass.

B&K are some really nice people, if you write and they have it they'll send you a .pdf schematic

 

I still say it's something simple, get a bright light and a magnifying glass.

B&K are some really nice people, if you write and they have it they'll send you a .pdf schematic

To replace the battery, the rear cover needs to be open up completely and exposing the circuit board. Could be some contact so you are right and need to look much closer.
thanks.