Mastech ms8229

[Kawooa]

I know this is an old thread but might someone be able to help? I have a Mastech ms8229 and for some reason it is acting up so weird. I have no idea what I did to get this but it want to measure ohms in the volts position. It won't measure the ohm or even notice any volts(testing with a aaa to not damage it). I opened it and looked carefully around and didn't see any broken parts or anything missing. I don't care about the meter but just want to know what it up with it. I died little over a year ago and I got much nicer ones after it did.

[Kawooa]

Re: Protek 6300 "5 in 1" DMM

Here is the picture. Just so weird.

[retiredcaps]

Re: Protek 6300 "5 in 1" DMM

I have no idea what I did to get this but it want to measure ohms in the volts position.

Sounds like the rotary switch isn't being interpreted correctly?

You will have to take it apart and post some clear focused pictures.

edit: If the rotary switch were on resistance, it should display overload instead of 0.000 with no probes attached. If the rotary switch were on volts, it should show 0.000 with no probes attached, but with V instead of the ohm symbol.

[retiredcaps]

Re: Mastech ms8229

I found a picture of the MS8229 front pcb at

http://fisch.suroot.com/mastechms822...ms8229_004.jpg

I circled what I believe is dirt/debris that may interfere with the proper operation of the multimeter? You can clean it with isopropyl alcohol.

[stj]

Re: Mastech ms8229

biggest problem with meters is the rotary switch - followed by the probe sockets.

i have to clean the switch contacts about once every 6 months.
i replaced the sockets with decent ones .

[Kawooa]

Re: Mastech ms8229

I opened it for only the 20th time today and cleaned the rotor switch with a old tooth brush and some rubbing alcohol and it still want to measure ohms in the volts position. I don't know what is causing it only that it is annoying. It wants to when I hit the select button switch between all the ohms functions such as ohms, diode, continuity, caps(nf). Only problem is that it doesn't measure only displays it as though it was trying.

[Kawooa]

Re: Mastech ms8229

Here is a picture of the rotor switch

[Kawooa]

Re: Mastech ms8229

I found a picture of the MS8229 front pcb at

http://fisch.suroot.com/mastechms822...ms8229_004.jpg

I circled what I believe is dirt/debris that may interfere with the proper operation of the multimeter? You can clean it with isopropyl alcohol.

If you can get a picture of the rotor switch. The part that turns for me I ca see if mine has the little contact pieces off and not in the right spot for what ever reason. Thanks for help so far!

[stj]

Re: Mastech ms8229

check the soldering between the 2 boards.

[Kawooa]

Re: Mastech ms8229

I grabbed my extremely bright flashlight and looked at most solder joints if not all and didn't see anything that looked off. I grabbed my tooth brush again and cleaned the entire board. Going to try in a couple minutes after it dries.

[Kawooa]

Re: Mastech ms8229

Closer! But I think some of those little contacts in the rotor switch are off. I now have volts on volts but all the other ranges are not the right things. Volts now is the only correct position but before and amps were the only ones off. I need a picture of someone's switch that isn't messed up so I can't see why mine if off and fix it.

[retiredcaps]

Re: Mastech ms8229

I need a picture of someone's switch that isn't messed up so I can't see why mine if off and fix it.

Let me ping someone who has the equivalent multimeter, but Harbor Freight branded. No guarantees and it might take a few days since he is busy.

[newtothis]

Re: Mastech ms8229

I have a couple of Mastech 83xx series, maybe same switch. Will look

[modemhead]

Re: Mastech ms8229

Let me ping someone who has the equivalent multimeter, but Harbor Freight branded.

Here you go. It's a Cen-tech P98674, looks pretty much like a Mastech MS8229.

[Kawooa]

Re: Mastech ms8229

I adjusted the little contacts but now it is back to how it was before. I must have moved one by mistake which gave me volts but no other range. I still don't have volts and amps as it wants to measure amps from the volts terminal. This is so weird.

[retiredcaps]

Re: Mastech ms8229

I still don't have volts and amps as it wants to measure amps from the volts terminal.

Can you post another picture like you did in post #2 of it showing Amps when in Volts mode?

[Kawooa]

Re: Mastech ms8229

Here are some photos showing ohms in volts range and amps in volts terminal.

[Kawooa]

Re: Mastech ms8229

Having issues due to snow storm and ipad acting up. This should be the ohms in volts position.

[Kawooa]

Re: Mastech ms8229

I am kinda thinking that when weather gets nice again and if I can't fix it I might since I don't care about it fry it. You know. Get my deep fryer and batter out. And fry it!

[retiredcaps]

Re: Mastech ms8229

Try interchaning the bottom 4 contacts with the top 4 and see if the volts and amps functionality work? The reason for moving them around is perhaps one of the contacts is bad or malformed? If moving them around results in different behavior that tells us something too.