I need a new tranformer - Dimplex DS5598 Mid-Size Heater

Check the control fuse on the power interface board and also the fuse inside the silver box. The control loop will prevent the heater from coming on if it is open.

This tv whistling sound are causes by a high voltage currents flow from it is tv power supply board it self not functions properly anymore.That the board where the power a/c cord plug into it.Those high voltages tranformers have gaps in it solders joints and now it not letting high voltages currents flow smoothly anymore,that where the whistling sound came from.Tries take the tv aparts,tries to put some kind harden or supper glues to all those high voltages tranformers,might help or soften the whistling sound alot.If that did not help all or alot.Try website like Ebay.com to buy a whole new refurbish tv power supply board for the replacement.

If the DC is 15v then the AC is around 12v.

This is beause 2 Capactors of the internal power tranformer were damaged. If you know how to open the casing and then open the tranformer to replace those 2 tranformer, 100% sure it will return to normal and last long.

it sounds like the laminate on one of the power supplies tranformers is loose a tech can either replace the tranformer or silicone the laminate

Is this a tube tv?IF it is the Flyback tranformer have a little still bar tranformer hight current volt make that noise take off the tv cover put some glue on the little steal bar should stop the noise or lower it very good.

Check for a loose connection where the problem "loop" connects at the tranformer.
Also, swap the "loop" connections to the tranformer. If the problem still persists replace the wire run. Sometimes wire gets damaged internally and visual inspection will not reveal that.
If the problem occurs in the other loop after the swap, then you probably have a bad connection inside the transformer. If that is the case, you won't be able to use that connection as the transformer has no user servicable parts.
Also, if the tranformer in under 5 years old, it's still under warranty.

The power supply is Logitech Model # GAD-SLU-240A8 P/N 190057-1000 OUTPUT IS 24V-----0.75A The output connector is positive center, negative outer ring.

You can try uninstalling the game and reinstalling it, as some files may have been corrupted on the initial installation.

try to reboot the machine after it boots then click on start button then all programs-accessories-system tools then click on system repair it will repair your comuter after then just reboot the computer.