There could be a number of reasons why its not working.
It is possible the transformer is faulty, particularly if it has an inbuilt thermal fuse but there is other stuff to check first.
Without seeing the circuit for this you have to start at the beginning and that means checking if any internal user replaceable fuses have blown. If you post a picture of the power supply we would have a better idea.
The transformer is easily checked by confirming that the primary winding is intact and giving a reasonably low ohms reading when checked for continuity. It could be as low as 10 ohms or so.
A couple of good pictures would tell us more.
It is possible the transformer is faulty, particularly if it has an inbuilt thermal fuse but there is other stuff to check first.
Without seeing the circuit for this you have to start at the beginning and that means checking if any internal user replaceable fuses have blown. If you post a picture of the power supply we would have a better idea.
The transformer is easily checked by confirming that the primary winding is intact and giving a reasonably low ohms reading when checked for continuity. It could be as low as 10 ohms or so.
A couple of good pictures would tell us more.
Thanks. I've pulled this out of the bag which looks similar but still not detailed enough to give specific instructions.
There seems to be a mains filter unit (unlikely to be faulty) too. That's the bit on the right of this picture.
What you need to do is try and confirm continuity with a meter set to a low ohms range. Unit off and unplugged of course. What you are trying to check is that the live and neutral leads from the mains plug have continuity to the transformer. The wires in that blue tubing look to be the primary side of things... lots of wires probably for different mains voltage options. You should read continuity from the live of the plug to any one of those wires and also from the neutral of the plug to any one of those wires. If so then the next step is to just read across those wires and conform the tranny isn't open circuit.
There seems to be a mains filter unit (unlikely to be faulty) too. That's the bit on the right of this picture.
What you need to do is try and confirm continuity with a meter set to a low ohms range. Unit off and unplugged of course. What you are trying to check is that the live and neutral leads from the mains plug have continuity to the transformer. The wires in that blue tubing look to be the primary side of things... lots of wires probably for different mains voltage options. You should read continuity from the live of the plug to any one of those wires and also from the neutral of the plug to any one of those wires. If so then the next step is to just read across those wires and conform the tranny isn't open circuit.
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Hi again and thank you very much
I've had to order some fuses which should be with me tomorrow. I had some fuses lying around and according to the back of the unit it says 0.5a surge fuse.
The ones I had where only standard fuses which blew straight away.
I did some tests on the tranny which you told me to do and have attached a pic of the results
I've had to order some fuses which should be with me tomorrow. I had some fuses lying around and according to the back of the unit it says 0.5a surge fuse.
The ones I had where only standard fuses which blew straight away.
I did some tests on the tranny which you told me to do and have attached a pic of the results
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It looks like the transformer is OK (not open circuit at least). So 20 ohms between brown and blue (live and neutral) sounds reasonable.
What value fuses were you using that blew straight away ? Were they marked F for fast.
You see its possible there could be a problem elsewhere. If there is a short on the secondary side such as a diode then that would blow the fuse too.
The fuse blowing and your continuity readings prove that the transformer isn't open, that all.
What value fuses were you using that blew straight away ? Were they marked F for fast.
You see its possible there could be a problem elsewhere. If there is a short on the secondary side such as a diode then that would blow the fuse too.
The fuse blowing and your continuity readings prove that the transformer isn't open, that all.
Hmmm. Don't despair yet. If it was the transformer buzzing then that could be down to a short on one of the rails.
Do you see the 8 large diodes where the tranny wires route to ? With your meter on 'diode test' range measure each one in circuit and confirm none are short circuit or almost so.
Also visually look at the large capacitors. Any sign of bulging at the top or leakage from the base ?
Things start to get more tricky after this without having a circuit diagram.
Do you see the 8 large diodes where the tranny wires route to ? With your meter on 'diode test' range measure each one in circuit and confirm none are short circuit or almost so.
Also visually look at the large capacitors. Any sign of bulging at the top or leakage from the base ?
Things start to get more tricky after this without having a circuit diagram.
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