DC Power Connectors - a warning - UK Vintage Radio Repair and Restoration Discussion Forum

Julesomega · 9th Mar 2019, 9:58 pm

A friend's workshop radio would no longer work from the power adaptor supplied, which is a phone-charger style 5V unit with micro USB cable connector. I surmised that the USB socket would have flexed on its sub-assembly board until the soldered connections broke loose, and I volunteered to guide him in resoldering it back. Inspection under an eyeglass showed this to be the case and we carefully reflowed it, a considerable challenge on these connectors. Still no sign of life and careful probing showed that the USB socket itself had fractured internally - that's what you get with repeated and energetic flexing.

I then offered to fit a new standard DC power socket (male) and fit the mating plug (f) on the cable. Worked perfectly of course, until I plugged the lead in a second time. Frustrating

Inspection of the new socket found that inserting the plug had pushed the connector apart, as shown. I centre-punched the contact strip (serves it right) and added a blob of Araldidte, and success at last.

Now the point is that these connectors, 5.5mm outer and 2.1mm inner, are found everywhere, sometimes with an appealing rubber seal to keep crud out when unplugged. They're made like this and failure is inevitable. They are the smallest of the screw-in types, but if you can use a slightly larger diameter connector, look for the Cliff Components types. They also feature a break switch for disconnecting the battery if needed.

MrBungle · 10th Mar 2019, 1:35 am

I’ve had a couple of the ones like your second from right picture. Both of them fell to bits within a week.

By this time I was thoroughly fed up. Everything has Anderson powerpoles on it now!

9th Mar 2019, 9:58 pm	#1
Julesomega Nonode Join Date: Dec 2012 Location: Stockport, Greater Manchester, UK. Posts: 2,102	DC Power Connectors - a warning A friend's workshop radio would no longer work from the power adaptor supplied, which is a phone-charger style 5V unit with micro USB cable connector. I surmised that the USB socket would have flexed on its sub-assembly board until the soldered connections broke loose, and I volunteered to guide him in resoldering it back. Inspection under an eyeglass showed this to be the case and we carefully reflowed it, a considerable challenge on these connectors. Still no sign of life and careful probing showed that the USB socket itself had fractured internally - that's what you get with repeated and energetic flexing. I then offered to fit a new standard DC power socket (male) and fit the mating plug (f) on the cable. Worked perfectly of course, until I plugged the lead in a second time. Frustrating Inspection of the new socket found that inserting the plug had pushed the connector apart, as shown. I centre-punched the contact strip (serves it right) and added a blob of Araldidte, and success at last. Now the point is that these connectors, 5.5mm outer and 2.1mm inner, are found everywhere, sometimes with an appealing rubber seal to keep crud out when unplugged. They're made like this and failure is inevitable. They are the smallest of the screw-in types, but if you can use a slightly larger diameter connector, look for the Cliff Components types. They also feature a break switch for disconnecting the battery if needed. Attached Thumbnails __________________ - Julian It's good here

10th Mar 2019, 1:35 am	#2
MrBungle Dekatron Join Date: Jun 2016 Location: London, UK. Posts: 3,687	Re: DC Power Connectors - a warning I’ve had a couple of the ones like your second from right picture. Both of them fell to bits within a week. By this time I was thoroughly fed up. Everything has Anderson powerpoles on it now!