40 Pin FPC Cable - 300mm length

This is a 40 pin FPC cable, 300 mm long, listed under Blue Alpine part number E00153-00. It’s white flat flex with a blue stiffener tab at each end, and it sells for $2.75. An FPC cable gets damaged more often than you’d expect. A sharp fold during a repair, a nick in the edge, or contacts scuffed from being pulled out at an angle can all do it.

What an FPC cable actually is

FPC stands for flexible printed circuit. The term gets used loosely, and you’ll also hear the same thing called FFC (flat flexible cable) or just ribbon cable. Inside the plastic film is a row of thin, flat copper conductors running side by side. It bends around corners and weighs next to nothing. The flexible flat cable article on Wikipedia has more on the type.

At each end the insulation is cut back on one face, leaving the conductors exposed as flat contacts. Those blue tabs are stiffeners. The film by itself is too floppy to push into a connector, so the stiffener gives you something firm to hold and press with. Grip the FPC cable there, never by the thin middle section.

Checking a 40 pin FPC cable against your old one

Three details have to match. Miss one and the cable either won’t go in or won’t work once it’s in.

• Contact count: this one has 40. Count the old cable’s contacts, or lay the two side by side and compare the width across the contacts.
• Length: 300 mm, about 11.8 inches end to end. Too short and it’s pulled tight against the connectors. Too long and the extra has to be folded somewhere.
• Contact side: check which face the bare contacts are on at each end. Some cables have them on the same face at both ends, others on opposite faces. The new FPC cable needs the same layout as the original.

The part number is still the quickest check. If your manual or parts list says E00153-00, that’s this one. No number, or a different one? Photograph both ends of your old cable and send the pictures to us first.

Getting the old cable out

Unplug the freeze dryer at the wall. Switching it off isn’t enough. Then photograph both connectors before you touch them, so you have a record of which way the contacts faced and how deep the cable sat.

Most flat-cable connectors have a small latch, sometimes called an actuator. Depending on the design it flips up or slides out a millimeter or so. Open it with a fingernail or a plastic pry tool. These latches are tiny and they snap under force, and a broken one won’t clamp the cable properly again. Once the latch is open, the old FPC cable should slide out with almost no resistance. If it’s still gripping, the latch isn’t fully open.

Touch bare, grounded metal before you reach near any circuit boards, or wear an ESD wrist strap. A static discharge too small to feel can still damage electronics.

Seating the new FPC cable

Hold it by the stiffener with the contacts facing the way your photo shows. Slide it straight in, square to the connector. Then look along the edge. It should sit at the same depth across its full width, with none of the contacts showing more than the others. Close the latch. Even one contact out of line can connect the wrong pins, so check twice before you close the panel.

Route the rest of the FPC cable in gentle curves. A soft bend is fine. A hard crease can crack the copper inside the film, and that kind of damage usually doesn’t show from the outside. Keep it off sharp sheet-metal edges, too.

The screen and digital board below are listed separately. Your manual’s parts list will tell you which cables go with which parts.

New cable in, same problem

A replacement FPC cable fixes a damaged cable. It won’t fix a fault somewhere else. If nothing changed after the swap, go back over these before ordering more parts:

• Both ends fully seated, both latches closed.
• Contacts facing the right way at each end (compare with your photos).
• No cracked latch. A loose clamp can look fine and still not make contact.
• Connector pins clean and straight. A flashlight helps here.

If all of that checks out, the FPC cable probably wasn’t the cause. Tell us what the machine is doing, any error it shows, and what was happening when the trouble started. Give us a call at +1 (443) 514-5708 or use the freeze dryer support page. The rest of our electronics replacement parts are listed together, including the buffer PCB board.