Advice on fixing a Radio Cassette Recorder power connection.

[SilverHifiMan]

Does anyone have any advice on how to repair a loose Radio Cassette Recorder power connection. Its a Sharp QT12. It works if I plug it in and hold the connection down lol.

I have never done soldering before.

Thanks

[DMcMahon]

From your description difficult to know what the cause might be.

1. Could be wear on the female socket pins on the cable plug
2. Could be wear on the male pins on the socket on the unit
3. Could be an intermittent break in the cable at the plug end
4. Could be an intermittent connection at the external connections on the unit socket

I was going to suggest trying another cable from another piece of equipment thinking that the plug on the cable might be a standard 2 pin figure of 8 but just looked at the schematic which shows it as a 3 pin connector, which depending upon actual type may be difficult to locate a replacement.

Can you post a photo of the cable plug and the socket it plugs into.

Does it work on batteries OK ?

David

[llama]

If the fixed socket is mounted directly onto the PCB there could be a cracked joint due to the slight flexing as the cable has been plugged in and out.
Graham

[DMcMahon]

Looking at the drawings in the Service manual it does look like the fixed mains socket (S0 301) is directly fitted to the Audio P.W.B.

So Grahams suggestion is good.

Recommend visually inspecting the fixed socket soldered connections at the Audio board looking for bad soldering/cracked joints/tracks. This may not be easy to see/access.

All inspection work should be done with the mains cable unplugged from the unit for safety.

David

[hamid_1]

It sounds like a bad connection between the mains socket and circuit board, which will need resoldering. Just in case it's actually a bad connection in the mains lead itself, can you try using another mains lead? From the pictures I've seen, it looks like a standard "Figure 8" type, as found on many items like Sky Digital boxes as well as other portable radios. You may well have another power lead in your house that you could swap with.

If it is a fault in the socket, not the lead, you have several options, assuming you can't re-solder it yourself. One option is to run the unit on batteries, preferably rechargeable ones for best economy. The mains socket on the recorder has a built-in changeover switch. Pull out the mains lead to use it on batteries. Inserting the mains lead disconnects the batteries. Because there's a possibilty that the changeover switch could be faulty or needs resoldering too, try some cheap Poundland batteries in the unit and check it works before spending money on more expensive rechargeables. It requires six 'C' size batteries. Rechargeable C cells are available, but it may be cheaper to use the more common AA size with adaptors like these: https://www.amazon.co.uk/dp/B09RGYMHSH/

Failing that, there may be a forum member close to you who could help you resolder the mains socket. Or you could post the whole thing to them. There is a special section for requesting help with repairs that you don't feel able to do yourself : https://www.vintage-radio.net/forum/...play.php?f=145

You could have a go at repairing it yourself. The first step will be to disconnect the mains lead, open the unit and examine where the mains connector meets the circuit board. The mains connector pins should be soldered firmly in place. If you gently wiggle the connector and you see the pins moving or a gap opening up between the connector pins and the circuit board, then it will need resoldering. If in doubt, you can post photos on here.

Soldering something like a mains connector shouldn't be too difficult for a beginner. There must be plenty of 'how to solder electronics' videos on YouTube for guidance, plus you can ask us. You will need a soldering iron, of course, (I suggest a 25watt - 40watt one) and ideally some 60/40 tin-lead solder, not the modern lead-free stuff - it doesn't mix well with the solder used on vintage equipment. Worst-case scenario if you mess up this cassette deck, you can buy another one relatively cheaply, so there's not much to lose.

[DMcMahon]

The service manual provides various disassembly instructions.

The first instruction at A is to remove the front cabinet, whether this will give adequate view/access to the mains connector at the board I do not know.

There is also instruction at D to remove the Audio P.W.B. (Printed Wiring Board), that would give full access to the mains connector.

Whether instructions at B and C also would have to be done I am unsure, but there are connectors referenced that would have to be removed to get the Audio board removed.

David

[SilverHifiMan]

Originally Posted by DMcMahon

From your description difficult to know what the cause might be.

1. Could be wear on the female socket pins on the cable plug
2. Could be wear on the male pins on the socket on the unit
3. Could be an intermittent break in the cable at the plug end
4. Could be an intermittent connection at the external connections on the unit socket

I was going to suggest trying another cable from another piece of equipment thinking that the plug on the cable might be a standard 2 pin figure of 8 but just looked at the schematic which shows it as a 3 pin connector, which depending upon actual type may be difficult to locate a replacement.

Can you post a photo of the cable plug and the socket it plugs into.

Does it work on batteries OK ?

David

Here is a picture of the connection on the side of the unit. Click on it to enlarge. And one of the pins connection on the plug. I will try batteries and post back the result.

[DMcMahon]

The cable plug certainly looks like a 2 pin figure of 8 connector, the schematics I saw showed a 3 pin.

As hamid 1 says these 2 pin figure of 8 mains cables are very common, if you have one on another piece of equipement then try that cable.

If you do not have another cable or get the same results then next step is to inspect the socket connector on the unit.

The socket on the unit looks a little different from a standard figure of 8 (see example attached) probably is the actuator for the switch to isolate the batteries when mains cable plugged in.

Does it feel like the mains cable is plugging in fully when inserted ?

David

[Martin Bush]

The socket on the OPs picture says 110-120v. Have I missed something?

[DMcMahon]

Yes well spotted.

The spec in the service manual says 110V-120V & 220V-240V

On the schematic the connector is shown as a 3 pin with one end being 120V and the other end 240V with the middle pin the AC common.

SilverHifiMan, if you loosen the screw in your photo does the cover around the connector slide down and then at the top show 220V-240V ?

David