SMD marking
R64in SOT-323
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.
R64 on a chip resistor
0.64 Ω
0.64 Ω resistor
The R stands in for the decimal point, which is how sub-ohm and fractional values are printed.
Check it with a meter
Lift one end and measure across it. A good one reads 0.64 Ω. Measuring it in circuit reads the parallel combination of everything around it, which is almost always lower, never higher: well above 0.64 Ω on the board is a fault. Open, or well above 0.64 Ω, means it has failed: burnt, cracked or corroded. That does not change what to fit: the marking still says 0.64 Ω. A burnt resistor usually means the part it feeds drew too much, so find that before fitting a new one.
On a transistor or diode body (SOT-323), R64 is a part code instead. Those parts are listed below.
The only part printed R64 in this package in our tables
BAR64-05W
- What it is
- Switching diode
- Maker
- Vishay
- Package
- SOT-323
- Pins
- 3
- Details
- RF PIN Diodes - Dual, Common Cathode in SOT-323
- Source
- From the manufacturer's datasheet
Is it dead?
Diode range, part lifted or one leg off the pad. Red probe on the anode.
Working, it reads
About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.
Dead, it reads
- The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
- Open both ways: failed open.
- A reading the wrong way round as well: leaky.
- On the board:
- 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 three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
Open this in the search to correct a character or try another package.