LisaList2

Quote from: berskyboy on September 18, 2026, 07:02:56 PMLead 2 to case = 3 beep,1.6
case to Lead 2 = inf, inf

Again, the lack of symmetry between short and open circuit measurements indicates a measurement problem.

Dunno what to say... keep fiddling with it until you figure out how to get consistent results... it may be the DMM, the leads, poor contact between the probes and the device...

Q2

Red to Black. (diode test, 200 ohm test)
Lead 1 to case = 2 beep, 0.6
case to Lead 1 = 3 beep, 0.6
Lead 2 to case = 3 beep,1.6
case to Lead 2 = inf, inf

Quote from: berskyboy on September 18, 2026, 06:46:01 PMcase meaning the top of the can?

Case meaning the silvery part of the transistor, so not the black heatsink (if still attached), not a surface with the thermal grease on it (if any is showing). The case is any part of the silvery domed cylinder and the trapezoid plate with screw holes it is attached to.

Perhaps there is oxidization or corrosion or some other contamination on the surface that you need to scratch through to make good contact.

Today at 06:35:45 PM
Last Edit: Today at 06:45:36 PM by berskyboy
Q2
Red to Black. (diode test, 200 ohm test)
Lead 1 to case = inf, inf
case to Lead 1 = inf , inf
Lead 2 to case = inf Beep , inf
case to Lead 2 = 4 Beep, inf

case meaning the top of the can?

having a hard time with the measurements

Quote from: berskyboy on September 18, 2026, 06:35:45 PMQ2
Red to Black. (diode test, 200 ohm test)
Lead 1 to case = 3B, inf
case to Lead 1 = 3B , inf

These don't agree... diode test shows short, 200 ohms says not short.... if not the DMM leads, perhaps the rotary switch of the DMM doesn't always make good contact?

Q2
Red to Black. (diode test, 200 ohm test)
Lead 1 to case = inf, inf
case to Lead 1 = inf , inf
Lead 2 to case = inf Beep , inf
case to Lead 2 = 4 Beep, inf

case meaning the top of the can?

having a hard time with the measurements

Quote from: berskyboy on September 18, 2026, 06:23:37 PM

Quote from: sigma7 on September 18, 2026, 06:10:26 PM

Quote from: berskyboy on September 18, 2026, 05:38:33 PMQ2
Red to Black
Lead 1 to case = 4 beep
case to Lead 1 = 4beep
Lead 2 to case = 3 beep
case to Lead 2 = 4 beep

Quote from: berskyboy on September 18, 2026, 06:04:26 PMQ2
Red to Black
Lead 1 to case = inf
case to Lead 1 = inf
Lead 2 to case = inf
case to Lead 2 = inf

These two sets of readings don't agree with each other.

The diode/continuity test says these are a short circuit, and the ohms test says these are an open circuit.

Can you figure out why? I presume the issue is my instructions are ambiguous in some way.

I see the meters from that company do contain fuses, so perhaps the fuse is in the ohms circuit... if you touch the DMM leads together does it show a short circuit in both diode test and 200 ohms resistance modes?

two leads together beeps and shows 002 in diode tests

and 0.3 in 200 ohm (no beep)

Perhaps one of the DMM leads is intermittent? Inspect them for damage, and in diode test mode, while connected together, wiggle and apply tension to all parts of the leads around to see if you can get the reading to change.

Quote from: sigma7 on September 18, 2026, 06:10:26 PM

Quote from: berskyboy on September 18, 2026, 05:38:33 PMQ2
Red to Black
Lead 1 to case = 4 beep
case to Lead 1 = 4beep
Lead 2 to case = 3 beep
case to Lead 2 = 4 beep

Quote from: berskyboy on September 18, 2026, 06:04:26 PMQ2
Red to Black
Lead 1 to case = inf
case to Lead 1 = inf
Lead 2 to case = inf
case to Lead 2 = inf

These two sets of readings don't agree with each other.

The diode/continuity test says these are a short circuit, and the ohms test says these are an open circuit.

Can you figure out why? I presume the issue is my instructions are ambiguous in some way.

I see the meters from that company do contain fuses, so perhaps the fuse is in the ohms circuit... if you touch the DMM leads together does it show a short circuit in both diode test and 200 ohms resistance modes?

two leads together beeps and shows 002 in diode tests

and 0.3 in 200 ohm (no beep)

Quote from: berskyboy on September 18, 2026, 05:38:33 PMQ2
Red to Black
Lead 1 to case = 4 beep
case to Lead 1 = 4beep
Lead 2 to case = 3 beep
case to Lead 2 = 4 beep

Quote from: berskyboy on September 18, 2026, 06:04:26 PMQ2
Red to Black
Lead 1 to case = inf
case to Lead 1 = inf
Lead 2 to case = inf
case to Lead 2 = inf

These two sets of readings don't agree with each other.

The diode/continuity test says these are a short circuit, and the ohms test says these are an open circuit.

Can you figure out why? I presume the issue is my instructions are ambiguous in some way.

I see the meters from that company do contain fuses, so perhaps the fuse is in the ohms circuit... if you touch the DMM leads together does it show a short circuit in both diode test and 200 ohms resistance modes?

Q2
Red to Black
Lead 1 to Lead 2 = 1.2
Lead 2 to Lead 1 = 1.2
Lead 1 to case = inf
case to Lead 1 = inf
Lead 2 to case = inf
case to Lead 2 = inf