Eh ???????

[Audio Al]

Just seen this on a for sale add :scratch:


Description

Offered as spare/ Repair as doesn't turn on

PAT tested for safety


Is it just me or :scratch:

[Patrick Dixon]

Yeah, the earthing's fine it's just the fuse that has blown.

[struth]

Doesn't have to work to pass a pat test. Just means it's electric ally safe

[walpurgis]

He's probably cut the mains lead off. It's very safe now! :)

[Audio Al]

If it's not working how can you check it's electrically safe :scratch:

[Lawrence001]

Plug it in and stick your fingers in any holes you can find? [emoji38]

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[Light Dependant Resistor]

If it's not working how can you check it's electrically safe :scratch:


Equipment that has failed always provides very good reason electrically why it has a fault, then again intermittent faults and partial faults
can create headaches to solve- but rest assured the answer is always there.

A multimeter can help to diagnose equipment to assess a basic level of safety . Set to read resistance ohms and ranged so that it is very sensitive, firstly assess the meter itself
by touching red probe to black - it should reveal the very small resistance of the test leads, but will be reading 0.003 ohms or close to that.

Any faulty equipment should obviously NOT be powered ON, rather with the lead attached to the equipment BUT NOT plugged in, you can test resistance from
Active to Neutral which tests if the transformer internally in the equipment is or is not creating a circuit with its primary winding. The attached image shows a test of a 20VA
toroidal transformer showing resistance above 90 ohms proving its a valid primary winding.

Further tests involve observing the condition of the fitted fuse - if its intact the equipment if faulty has a very minor fault
if on the other hand the fuse is blown - you can observe if the fuse element has simply broken or worse it has shattered into
many pieces - inferring a major fault.

A testing technician will usually always take the precaution of using tools like a variac that can gently power the faulty equipment
rated at 240v AC with a much lower voltage like 50vAC to discern the exact location of a fault. A technician would also call upon
the schematic which is a drawing of all of the components how they connect, and would look for obvious faults like burned components

Equipment which displays continual faults invariably is not as well designed as it could be, and requires complete overhaul to
address the issues.

[Audio Al]

Chris

Thanks for the reply , if I buy said item i will give it a go :)

[Beobloke]

You can carry out a partial PAT test on a Class I item that doesn't work, as this will still check out earth leakage across the main supply inputs to earth, which will give a warmer feeling that at least something catastrophic hasn't occured, melted all the insulation and shorted things to the case. That said, the earth leakage under operational conditions cannot be successfully performed.

It may all be academic anyway, as most of the items I've bought with PAT tested stickers on have either been carried out by a conman, or someone who doesn't know what they are doing. The first thing I check before powering anything up is the fuse condition and rating in the plug and, if I had £1 for the number of times I've found a 13A fuse fitted, I'd be quite wealthy!

[Firebottle]

Same here, with a new item on the bench I always check the fuse rating and how well the plug is wired, if not a molded plug.

The worst I ever saw, admittedly decades ago, was about 20mm of bare conductor from every terminal within the 13A plug :eek:

[struth]

came across a nail as a fuse... insulation gone in umpteen positions. a russian radiogram with the iec type plug pins on the outside(as standard from factory) that one electrocuted me actually...:doh:

[Barry]

I've seen items for sale where silver paper (taken from a fag packet) has been wrapped around a blown fuse in the plug top.

[Alex_UK]

Back in the early 90’s when I was doing mobile DJing I remember dashing off to the local petrol station to by a packet of polos to use the silver foil for the same thing when a fuse blew and I had no spares! :eek:

[sumday]

Working for repair/calibration firm in the 90s, I once PAT tested a VERY expensive Hewlett Packard all singing, all dancing touch screen scope.
No instructions not to PAT were passed on by the cal tech.
The result....a small crack, a comedy whisp of smoke and the cooling fan did a couple of revs.

This piece of kit was factory fresh and only in for certification....the workshop manager had an abortion.

[Lawrence001]

Working for repair/calibration firm in the 90s, I once PAT tested a VERY expensive Hewlett Packard all singing, all dancing touch screen scope.
No instructions not to PAT were passed on by the cal tech.
The result....a small crack, a comedy whisp of smoke and the cooling fan did a couple of revs.

This piece of kit was factory fresh and only in for certification....the workshop manager had an abortion.Surely PAT testing an item shouldn't blow it unless there's a fault regardless of age, so you probably did someone a favour?

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[Pigmy Pony]

Back in the early 90’s when I was doing mobile DJing I remember dashing off to the local petrol station to by a packet of polos to use the silver foil for the same thing when a fuse blew and I had no spares! :eek:

DJ Alex playlist:

Free Electric Band - Albert Hammond
Bang Bang - BA Robertson
I'm On Fire - 5000 Volts
Death on Two Legs - Queen
Flashdance (What a Feeling) - Irene Carra
Electric Avenue - Eddy Grant

[Barry]

Not forgetting 'Electricity' by Captain Beefheart and the Magic Band. :)

[Macca]

And AC/DC 'High Voltage'