Need help about understanding power transformer of a cassette deck, please.

[Skywavebe]

Transformers are usually not regulation devices and certainly not in these decks. To put in 220Vac and still get 12 V out is very unusual unless you have a transformer that is designed to do that but I suspect his measurements are wrong. Transformers are voltage conversion devices and also invers current translation devices. Before ordering a custom made transformer it would be wise to apply DC voltages at current limited abilities to the section and see if they light up or what the regulators do to the voltage. If it is a fuse link then that is due to over current most times and I have repaired transformers as to fuse links and put the inline fuse on the device but that was not what happened here I don't think.

 

[Skywavebe]

Well it will be interesting on what the solution comes to be. A technician with all kinds of parts and test equipment around might be able to rig up a test system with several power supplies- they don't have to be all from one transformer. There are some rare cases where two transformer were put in a unit that then allowed the unit to work- the Primaries were just wired in parallel to the power switch. There might even be a transformer sitting in a broken down Sony on E bay as I am sure there are many of them that do not work and will be sold for parts. This is one of the most dangerous thing to do with a deck. I did have a client that has a 240Vac 688 and he plugged it in to USA 117Vac and did not know why it did not work- he took it to TAP and they wanted $800 for a repair, lucky for him he sent it to me and I told him to get a step up transformer- I tested it for 4 hours and it worked fine. Some $800 repair they wanted to do! Why can't shop be honest with customers?

 

[BlazeES]

I'd go so far as to skip a 'custom' transformer all together and would alternatively recommend that one find a parts mule deck and go from there...

 

[Skywavebe]

That would be wise as this would make things less complicated. They know what the deck consumes power wise as stated by serial tag so now it is just a matter of selecting a couple transformers to do the job- you can work on the high side of power as a transformer made for more amps will be loafing in this deck. MPJA.com is a place to get them as well as ALL Electronics and other surplus suppliers. I would ohm out filaments of tubes and see if section like the control system would come up with a outside supply and if all works then a new transformer might be sought out. With all the aggravation of this it might be better to get a Nakamichi.

 

[vince666]

thank you both for further replies... and then will be sending further translations to italian to my friend.