Pulsar Minipak - No Low voltage supply

[Hilary Watts]

I have been asked to help with the repair of 3 Pulsar minipaks (of the 3 x 15A socket variety). On two of them one of the channels does not work and it looks as if the triac has gone short circuit so it should be a simple matter of replacing the triacs. On the third there is no low voltage supply, either at the DIN sockets or to the circuit board as a whole, although the mains supply does get as far as the circuit board - ie the main electronics on/off switch and associated fuse are not at fault.

 

I suspect all three packs have been abused in that the original 5A channel fuses have at some time been replaced by 8A fuses, so it is not surprising some of the triacs have gone. However, the units are in good condition physically and there is nothing to show why the LV supply should have failed on one out of three. Unfortunately the mains transformer connections are not accessible without removing the entire circuit board, and I am hoping to avoid doing this!

 

Has anyone come across this fault before or are there any suggestions as to what the fault might be?

[Stage and Seating Man]

The best people to ring are pulsar, the chap to start off with is a guy called 'Snowey' he is very helpful. The tel no is 01223 403 500 Good Luck

[Hilary Watts]

Thanks for the suggestion. I rang Pulsar - Snowey is not in today but a gentleman in the service Department suggested it is probably worth checking the mains transfomer - I'd better get out the screwdriver and soldering iron!

 

Hilary

[Hilary Watts]

Just an update to say all 3 packs are now working. As I thought, 2 of them simply needed triacs replacing while on the third the primary on the mains transformer was open circuit. Pulsar supplied a replacement transformer at a cost of £18.48 including VAT, P & P and next day delivery, which seemed very reasonable - all credit to them!

 

Hilary