SMD code R1188
Marking codes are not standardised, and the same code is reused by unrelated makers for unrelated parts. Below is every part in our tables printed with it, and any printed with a code that is easy to misread as it, from the manufacturers' own marking tables and published code lists.
R1188 on a chip inductor
0.12 µH
0.12 µH inductor
The R stands in for the decimal point, in microhenries: 0.12 µH. SMD power inductors below 10 µH are printed this way. The same marking also reads as 0.12 pF on a capacitor, and nothing in the code says which; the body of the part does.
Other readings of the same characters, most likely first
- 0.12 pF capacitor
Check it with a meter
Measure it on an LCR meter, out of circuit. A good one reads close to 0.12 µH. An ohmmeter only shows the winding resistance, which is a fraction of an ohm on a good part and says nothing about the value; open circuit means the winding has failed. Shorted turns still read near 0 Ω on an ohmmeter, so only the LCR meter, or an identical part beside it, shows them. A failed reading does not change what to fit: the marking still says 0.12 µH.
On a transistor or diode body (SOT-89), R1188 is a part code instead. Those parts are listed below.
2 parts are printed R1188
Not sure which one you have?
Answer up to 4 quick questions and these 2 parts are ranked, with a meter test that settles it. It works on a dead part too.
PNP transistor, all SOT-89, 3 pins. What differs:
2SB1188GPSOT-89ChenmkoChenmko
- What it is
- PNP transistor
- Maker
- Chenmko
- Package
- SOT-89
- Pins
- 3
- Details
- PNP Medium Power Transistor, 32 V, 2 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: PNP transistor.
2SB1188PT-RSOT-89Chenmko EnterpriseChenmko Enterprise
- What it is
- PNP transistor
- Maker
- Chenmko Enterprise
- Package
- SOT-89
- Pins
- 3
- Details
- PNP transistor: AF, Sw, 32V, 2A, B=180..390, 100MHz
- Source
- Published code list
Is it dead? The meter test is below: PNP transistor.
Is it dead? One meter test per kind
Parts of the same kind are tested the same way, so each test is here once. Each part above points to its own.
PNP transistor
Diode range, part lifted or its base leg off the pad.
Working, it reads
Black probe on the base reads about 0.6 to 0.75 V to the emitter and to the collector, and open the other way round. Collector to emitter reads open both ways.
Dead, it reads
- Collector to emitter the same both ways, near 0 V with a continuous beep: shorted. The commonest failure.
- The base the same both ways to another pin, near 0 V or a middling value: a shorted junction.
- Only one junction reads, or none: a junction has failed open. It then looks like a diode.
- A reading the wrong way round, where it should be open: leaky.
- On the board
- this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
- Compare:
- If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
- Watch for:
- A pair of diodes with a common pin reads just like a transistor, and some transistors carry a built-in diode or resistor. The datasheet says which.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
Did you find your part?
Open this in the search to correct a character or try another package.