If you work with electronics, you've probably seen a “6 pin hirose” connector on a spec sheet and just ordered it. I've done that. Most of the time it's fine. But when it's not fine, the troubleshooting eats hours, especially when the connector sits between a power supply and a device's main board.
This is the checklist I use before I approve a sample of hirose cables for a bulk order. It works with a $30 digital multimeter, 15 minutes of your time, and no special tools. It won't catch every possible failure, but it'll catch the ones that usually cause the “device was DOA” calls.
Why test at all?
The obvious answer is that a faulty cable can damage a device. The less obvious answer is that a faulty cable costs more than the cable itself.
I don't have hard data on how many connector failures are actually miswired harnesses, but from the returns I've processed, a lot of “bad device” reports turn out to be a cable that wasn't wired the way the schematic said. If you're buying generic or aftermarket hirose connectors, testing one sample before committing to 500 units is worth the time.
Let me give you a concrete example. Earlier this year, I compared quotes from four vendors for 6-pin hirose cables. One vendor was about 30% cheaper. I skipped the continuity test on the sample because, honestly, the sample looked fine. Then a customer's device wouldn't power up. Turned out two wires were reversed. The rework and the delay erased the savings completely. That's TCO, not just unit price.
Before you start
You don't need a lab setup. Here's what's on my bench:
- A multimeter with continuity mode and ohms mode. A basic one is fine.
- Two probe sets—one with sharp tips, one with alligator clips.
- The official pinout document for the connector or cable. If you're using a hirose part, start at Hirose Electric USA's website (hirose.com) and search the series name, like HR25 or DF13.
- Something to record your measurements. Even a piece of paper works.
The datasheet is the most important part. Not a screenshot from your supplier, not the drawing from a random forum—the official product print. According to Hirose Electric USA's product library (hirose.com), the HR25 series, for example, is available in configurations up to 20 positions, including 6-position versions. The exact pin layout depends on the series and shell size. I've been burned more than once by assuming the pin order was “standard.” It often is, but “often” isn't worth a shorted board.
How to test a 6-Pin Hirose connector with a multimeter
1. Mark pin 1 on both ends
Find the marker on the connector shell—usually a triangle, a notch, or a colored dot. If you're testing a female connector that's soldered to a device, also find the matching pad on the other side of the PCB. Keep in mind that the pin order is mirrored between the front and rear views. If you mix this up, every measurement you make after that is garbage.
Checkpoint: you can point to pin 1 on each side of the cable or connector, and the label you put there matched the datasheet.
2. Set the multimeter to continuity mode
The continuity mode usually shares the same position as the diode symbol on the dial. Touch the two probes together first. If you don't hear a beep, stop. The battery might be dead, or the probes might be broken. This sounds too simple to mention, but I once spent ten minutes “testing” a cable that was perfectly fine while my multimeter had a dead battery.
3. Test end-to-end continuity, pin by pin
Put one probe on pin 1 at one end, and the other probe on pin 1 at the other end. Wait for the beep. Repeat for pins 2 through 6.
For a standard 6-pin hirose cable, the pin mapping is usually 1-to-1, but not always. Some manufacturers build cross-wired or partially crossed cables for specific devices. The datasheet will tell you what you should expect. If you're testing the port on a device, use the schematic to identify the board's test point for each pin and compare it to the connector pin.
Checkpoint: every one of the six pins has a clear, stable beep. If a pin beeps and then stops when you wiggle the cable, you've got a frayed wire.
4. Check for shorts between pins
With nothing connected to the other end, touch the probes to pin 1 and pin 2. There should be no beep. Then pin 2 and 3, pin 3 and 4, and so on. A beep means there's a short. You might also check each pin to the shell if the connector has a shield, but the datasheet should tell you if one of the pins is actually tied to shield. Sometimes pin 6 is ground and connected to the shell by design.
This step catches solder splash, damaged insulation inside the connector, and cheap tooling from a low-cost manufacturer.
5. If the circuit is live, verify voltage
If you're checking a device that already has power, switch the multimeter to DC volts (or AC if the device uses it, though most small hirose connectors I've dealt with are DC). Place the black probe on a known ground pin, and the red probe on the pin that should carry supply voltage. Compare the reading to the schematic.
This is where I nearly made a costly mistake. I knew I should double-check the pin numbering on a 6-pin hirose connector inside a device with a 7.1 audio board, but I figured it was the same layout as the other model. The multimeter read 0V on what should have been a 5V line. I had the probe on the wrong pin—direction of the socket was reversed from the previous version. Good thing I hadn't plugged the fully assembled harness in yet.
6. Measure contact resistance for mated pairs
Set the meter to the ohms range, usually 200 or 400. Touch the two probes together and write down that number—that's your lead resistance, maybe 0.3 ohms. Now, with a male and female hirose shell mated, put one probe on a male pin and the other on the corresponding female pin on the other side. Subtract the lead resistance. Above 1 ohm, I'd want to know why. Above 2 ohms, I'd reject that sample.
The catch is that this only measures DC resistance. It doesn't measure high-speed signal integrity, characteristic impedance, or shielding effectiveness. If your application is high-speed, you'll need a different set of tools. For power and simple signals, this is enough.
7. Log every result
This is the step I never did at first. It's also the step that saved the most money.
We didn't have a formal test log back when we ordered a batch of “compatible” 6-pin hirose cables. After the third time we ordered a connector from a new supplier and had to re-test the entire shipment, I built a simple one: date, vendor, part number, pin map, pass/fail, and notes. Now it takes me five extra minutes to fill out, and it makes it much easier to push back on a vendor with actual evidence.
If you're a one-person operation, you don't need a spreadsheet. But write the results somewhere. Your future self will thank you.
What a multimeter won't tell you
Let me be clear: the multimeter is a sanity check, not a quality certificate. It won't tell you:
- Whether the cable passes high-speed signal requirements. For that you need an oscilloscope, time-domain reflectometer, or a network analyzer.
- Whether the shielding is effective over the whole length of the assembly.
- Whether the connector will survive vibration, temperature swings, or waterproofing tests.
- Whether the plating on the contacts is genuine gold or something that looks like gold.
The best use of a multimeter is catching assembly errors—the boring, expensive, totally avoidable failures. It's not a substitute for the manufacturer's testing.
Common mistakes to avoid
One final note about the “6 pin hirose” label. It's not a single product. The 6-pin HR25 series is a circular, push-pull connector, while a 6-pin DF13 is a flat board-to-board connector. Both are hirose, both have six pins, but the pins are different sizes, and the spacing is different. If you test the wrong connector against the wrong datasheet, you'll get false confidence and maybe a damaged port.
Also, ignore wire color until the multimeter agrees. I've seen a vendor use red for ground because they were out of black. That might be rare, but a memory of “the black wire is ground” is not a pinout. Verify, then trust.
And if you're comparing suppliers, don't stop at the quote. I've watched a lower quote disappear under return shipping and rework costs. The cheapest cable is only the cheapest if it works. Test first.
Ask an engineer about this topic