Monitor/mains connection

[ss]

As per previous post I have now opened up the monitor and checked the mains connection but cannot see anything wrong with it. (images attached) The mains connection was intermittently cutting out, would make a slight crackling noise, if the cable was wiggled it would reconnect. If I jolted the desk it sits on it would also cut out on ocassion so I am quite sure it is the mains connction but cant see anything.I also tried a substitute mains cable but that made no difference.

Anything else I should try while I have it apart (I am not electronic literate)

[whisky-dave]

It does look OK although there's a line on the soldering pad of £L1 in the centre of the frame, might be worth resoldering that. Also it could be the pins of that plug not connecting to your new cable socket due to wear or dirt so might be an idea to clean/polish the pins. On a friends monitor the pins were slightly bent too, but that just needed a new cable socket.

[alan_m]

How tight is that fuse in its holder? (the white bodied item to the right of the blue capacitor)

[Mr Pounder Esquire]

Dirty mains connection on the monitor? Try cleaning the plug connection on the monitor using a toothbrush with meths on it. Mrs Pounder had a mobile phone that would not charge, I used the above method on the phone charging insert thing and the phone now charges up with no problems. The insert thing on the phone did not look to be dirty.

[T i m]

Wouldn't the answer be 'very' as they are normally spot welded into the 'holders'?

Cheers, T i m

[Brian Gaff]

Well no use showing a picture to me mate. However if you can actually here it then there're probably signs of the connection sparking. The usual culprit is the connections on the pcb if its a pcb mounted mains connector, failing that if the stress on the socket is the problem the connection on the socket itself, often crimped or welded can become loose or corroded or worn. If you can trace the connections through from pin to wire best use a meter and wiggle things and see what gives, literally. The last one of these I met was on a Philips device and it turned out to be dry joints on the pcb where the ends of the mains socket was soldered. Heat them up well and apply leadeed solder but be aware that another problem can be the foil lifting and cracking and then you have to start thinking about bridging cracks with wire. I'd definitely find somebody used to working on pcbs before you experiment on it yourself. I used to be good at it but not with no sight!

Brian

[Brian Gaff]

I have had fuses that were in themselves intermittent in the past, but worth a look. Brian

[Brian Gaff]

You would be surprised, I can assure you.

Brian

[Brian Gaff]

Are we talking a low voltage connection or a mains voltage one here? If its low voltage it is almost certainly the socket from past experience. If mains level usually the soldering. Of course either way if you can trace the wires, justcut out the plug and socket drill a hole fit a strain relief and solder the cabble onto the pcb. No more plug troubles!

Brian

[T i m]

I'm happy to be surprised but I'm not sure that will assure me at all. ;-)

What you probably can't see is that I don't believe that it is a 'fuseholder', it's a std glass bodied fuse that has been spot welded into two wired end caps that are then soldered into the board like any other component. That's not to say they missed out on the spot-welding phase of course ...

Cheers, T i m

[tabbypurr]

welcome to uk.d-i-y doing electronics, more noise than signal.

[The Natural Philosopher]

mostly contributed by you.

A can of freeze spray is one way to identify any rocky joints. Resoldering them all is cheaper. I once resoldred every single eyelet on a TV set I had - at least 4 were dodgy, and I never identified which ones they were, but the faults disappered one by one as areas of the board were soldered.

[T i m]

I was looking at the ends of the IEC plug pins where they are split to retain them in the uprights that in-turn are soldered into the PCB. I wonder if the OP can move the pins at all as they should be solid (and given there is no other obvious issue)?

Cheers, T i m

[ss]

Everything appears to be rock solid including the fuse, I cant see any movement at all.

[T i m]

Ok, so what about where the ends of the pins are split to hold them in the socket itself, do they look 100% and could you clean them up and get a bigish iron in there (and some flux etc) and solder them in as well?

If you had a continuity tester (beeper) you could clip one end onto the mains plug (L then N etc) and put the other probe around the back of the socket / PCB as you wiggle the plug etc? Much easier to hear than see on an ohmmeter (especially digital) and safer than trying the same on the mains etc.

Cheers, T i m

[ss]

Yes I have a continuity tester so will have a go with that later today. I will see what I can access with the soldering iron. I am fast approaching the nothing to lose stage :-)

[T i m]

Good for intermittent connections as they normally screech and wail. ;-)

If you do try that it will need to be a big iron to 1) Get enough heat in there to get the solder to flow round the pin and plate and 2) get enough heat in there quickly, no as to not overheat / melt the socket.

That's always a good POV for such things. ;-)

If it does turn out to be the socket and you can't find a replacement easily, you could always add a flying socket by cutting an IEC extension lead in half and just making sure it's retained properly at the screen end.

Or, depending on cable access, just a straight mains lead soldered directly etc?

Cheers, T i m

[GB]

That's a bit unkind, but I much prefer things I can see, and those itty-bitty electrons are so small and quick!

[tabbypurr]

Better to caution people asking for advice really. Sci.electronics.repair is a suitable ng.

NT

[Bob Eager]

It's so hard to get an angle grinder on them.

And WD-40 makes them stick together.