Failure mode of mains network adapter?

A friend has a ZyXEL mains network adapter (model no. PLA4211).

It's suddenly just stopped working with no lights coming on at all (normally 3 LEDs visible). If I put my ear right up to it, I can hear a faint rapid ticking coming from the unit (4-5 clicks per second).

After making a triangular screwdriver I've opened it up but to my admittedly rather untutored eye, I can't see anything amiss. No sign of overheating, no bulging capacitors, no sign of anything leaking.

I can't help thinking that the ticking can't be normal. Any suggestions?

Tim

Reply to
Tim+
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Ticking sounds like an SMPS in shutdown, worth checking for a shorted diode on the secondary side at least.

Reply to
Lee

Ah, that's probably beyond my limited skills. Not quite sure what *would* be within my capabilities having seen the inside. Most of the components are tiny surface mounted things that I can't do anything with.

On the plus side, I have a triangular screwdriver now. ;-)

Tim

Reply to
Tim+

Some pictures (if that's of any help to anyone).

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Tim

Reply to
Tim+

If you have a DMM,check that melf* diode, I've seen a few of those fail short.

Has that unit been worked on? It looks like it's been hand soldered in places. Also, did the failure coincide with any of the storms recently, because if it did I wouldn't bother investigating it any further :) :)

*The thing in the glass package.
Reply to
Lee

I tend to agree. Round here with overhead 11kv and 33KV stuff, storms tend to pop the odd wall wart, router or mains kit now and again./ Its juts part of the cost of living as far as I am concerned

Reply to
The Natural Philosopher

Doubt anyone has been inside it since it left the factory.

We haven't had any storms for a long time.

These thingies? D105 and D103?

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Look way too teeny for my muckle fists to do much with alas. ;-)

Tim

Reply to
Tim+

Its the revenge of the short wave listener who has developed a secret weapon to put these interfering little buggers out of commission. Brian

Reply to
Brian Gaff

Can't help directly, but over time I found myself the proud owner of some dead units.

I suspect the fact they cannot be used in protected circuits may be a factor in their apparent delicate nature.

Reply to
Jethro_uk

Indeed. By definition they have to have a fairly high degree of connection at high frequencies, so excessive HF energy - as in Lightning or arcing - will feed straight into the modem.

And unless they put 50c worth of balun in there, chances are the electronics will die.

Reply to
The Natural Philosopher

Care to elaborate?

Reply to
Huge

The adapters I have are not able/supposed to be used in surge protected multiway adapters, or indeed multiway adapters of any stripe.

Reply to
Jethro_uk

Oh, I see. Thank you.

Reply to
Huge

+1. On hols in Cornwall last week the storm took out the BT hub.
Reply to
newshound

In a previous life I used to work on office phone systems. When there was a storm you could guarantee work would come in the next morning. Philips "Sopho" systems were particularly vulnerable.

Reply to
Graham.

SWMBO went to work on Monday (she runs the computing dept at a large school). Thunderstorm Sunday, and ALL the servers were out, network ditto.

Reply to
Bob Eager

True, but IME bandwidth is reduced considerably.

Reply to
Jethro_uk

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