JST Connector Chart: Wire-to-Wire Options, Cordless Phone & Nokia 3310 Repair, and How to Reset a Locked Phone

Quick intro before the questions. I handle rush orders for electronic components at a connector supply company. In the past six years, I've processed well over 1,000 urgent orders for JST connectors, wire harnesses, and crimp terminals — including same-day turnarounds for manufacturers whose assembly lines literally stopped.

This FAQ is the condensed version of conversations I have every week. If you're trying to read a JST connector chart, pick the right wire-to-wire connector, or you've got a cordless phone (or even a Nokia 3310) that won't reset because of a hardware problem, this is for you.

1. What does the series name mean on a JST connector? (PH, SH, XH, VH, SUR)

The series code tells you the pin pitch — the distance between the centers of two adjacent pins, in millimeters. This is the most important spec, and it's where misorders happen.

• PH — 2.0mm pitch. The all-around workhorse: battery packs, LED boards, sensors.
• SH — 1.0mm pitch. Small stuff: phone LCDs, tiny sensors, thin ribbon wires.
• XH — 2.5mm pitch. Battery connections in phones, toys, and cordless handsets.
• VH — 3.96mm pitch. Higher-current power connections.
• SUR — 0.8mm pitch. Ultra-thin wire-to-board connections for tight spaces.

What most people don't realize is that PH and XH connectors look nearly identical in product photos. I've had customers swear they needed an XH when the pitch was clearly 2.0mm. I do not mean this happens occasionally — it's a weekly occurrence. The difference between 2.0mm and 2.5mm is half a millimeter: easy to miss in a photo, impossible to ignore when nothing clicks together. We built a digital identifier for exactly this problem, and it's cut wrong orders significantly compared to the old “describe it over the phone” method.

2. Which JST connector is best for wire-to-wire connections?

For wire-to-wire work in consumer electronics, PH and XH are the series you'll encounter most. In a wire-to-wire JST connection, you crimp a metal terminal onto each wire, insert the terminals into a plastic housing, and the housings mate. The housing just holds everything in place; the terminal is what carries the signal. That crimp is where the quality lives.

People think sourcing the housing is the hard part. It isn't. The hard part is the crimp. A loose crimp will pass a continuity test, then fail a month later when the device gets bumped around. Per JST's published crimp specifications, the terminal has to form a gas-tight connection with the wire strands, and the wire should not pull out under the rated tensile force. That requirement won't be met by squeezing a terminal with pliers.

If you're doing any volume at all, buy a proper crimp tool with the correct die for the series. It's the difference between a connector that works and one that maybe works.

3. Why are JST connectors everywhere in cordless phones and the Nokia 3310?

Because they're cheap, reliable, and standardized. Honestly, that's the whole answer — and it's why these connectors show up in both old and new devices.

Inside a typical cordless phone base station, the battery pack connects through an XH or PH connector, while the speaker and mic wires use smaller-pitch PH or SH connectors. The Nokia 3310 — one of the most repaired phones in history — used tiny JST-style connectors in the SH range for its LCD and keypad flex cables. When retro repair guides talk about fixing a 3310, they're often describing how to re-seat or replace these small connectors.

These aren't exotic parts. That's the point. They became the industry default because they're available globally and the crimp tooling is everywhere. And because they've been in production for decades, replacement parts are easy to find — which matters more than you'd think when a phone or base station is five years past its support period.

4. Can a loose connector stop a locked phone from resetting?

Not the lock-screen type of lock. I mean the scary version: the phone seems completely dead, button presses do nothing, and the standard reset combo doesn't work. Before you declare the device dead, check the battery connector. It's the most common intermittent failure I run into.

Real case: in March 2024, a client's service line went down because their cordless handset wouldn't power on. They'd been hitting the reset button for two days. The reset was useless because no power was reaching the board at all. Inside, the PH battery connector had worked loose. One re-seat and the phone powered up instantly. So glad I talked them through the hardware check before they ordered a $220 replacement.

So if you're searching for “how to reset phone when locked” and the usual methods do nothing, open the device and check the battery and flex connectors first. It's a five-minute check. One customer's “bricked” Nokia 3310 turned out to be a loose LCD connector — the phone was running, but the screen wasn't displaying anything.

5. What's the fastest realistic way to get JST connectors in an emergency?

Same-day and next-day service is real, but it's not magic. It depends almost entirely on one thing: whether you know the exact series. As of January 2025, standard PH and XH housings and terminals ship same-day from our US warehouse if the order lands before noon. Less common series or custom wire harnesses? Best case is two to three days, even with expediting.

Last quarter, we processed 47 rush orders and hit the deadline on 44 of them. The three misses were all custom harnesses where the client changed the wire length after production had already started. One of those changes — a 40mm difference — cost the customer a full day of line downtime. So my advice: lock the spec, then ask for speed.

Honestly, speed also depends on whether the supplier has digitized their inventory. Our stock system is live, so a customer can send a photo of an old connector and get a match within minutes. Suppliers still tracking stock on spreadsheets can't match that turnaround.

6. What don't vendors tell you about JST connector pricing?

Here's something vendors won't tell you: the “standard lead time” you're quoted isn't necessarily how long your order actually takes. Suppliers build in buffer to manage their production queue. About half the time, orders could ship faster than the quote — but nobody benefits from promising a tighter deadline.

And the pricing assumption. People think genuine JST connectors cost more because they're a Japanese brand with higher manufacturing costs. Actually, the manufacturing cost is close to the compatible parts. The premium is in traceability, QC documentation, and material consistency. In production electronics, you're paying for proof and reliability, not for the logo.

One more thing: the first quote is rarely the final price for ongoing business. Once you've proven you're a reliable repeat buyer, there's room — especially when you're ordering standard series in volume.

7. Are “JST-compatible” connectors the same as genuine JST parts?

Physically compatible? Usually. The same? No.

I've tested plenty of Chinese “JST-compatible” housings and terminals sold at a fraction of the price. Some are fine for prototyping. But I've also seen crimp terminals crack under the die, housings warp at room temperature, and contacts whose plating wears out after a few insertion cycles.

For prototypes, use whatever works. Anything that ships to a paying customer? Genuine JST, period. Our company stopped stocking compatible SH connectors in 2023 after two failed batches, and now anything that goes out same-day is genuine. It costs a bit more per unit, but it's saved us far more in returned orders and burned trust. And if you're selling products that might be repaired, genuine parts make troubleshooting easier for whoever comes after you.