TV will not come on at all-Westinghouse LTV27-W2

Are you sure it`s the power supply?? Has the LOT (Line Output Transistor) or LOPTX (Line Output Transformer) gone short circuit or failed?? Disconnect the set from the mains, disconnect the PSU (Power Supply Unit) from the set and perform a resistance check. The easiest way to do this is to remove any (if there is one) covers off the LOT case and check the resistance from the LOT Casing (Collector) to the metal chassis / the tuner casing or any other metal chassis connection. It should read quite high in one direction due to the efficiency diodes. If the LOPTX/LOT has failed, the reading will be quite low in both directions. Note!! The aerial socket may be isolated so don`t use that as an earth. Another tell tale point is to switch on the set and listen carefully to the PSU, If it`s tweeting or a high pitched whistle, there`s more than likely to be a short on the secondary side of the PSU (Decoupling caps inside the PSU casing) or as I said earlier, the LOT/LOPTX. To test the PSU, disconnect the line output stage and connect a mains powered light bulb to the 90 - 120 volt output lead of the PSU which feeds the LOT/LOPTX. You may need to keep the other leads connected to the set because some PSU`s are turned on by the sets remote control uPC. I hope I`ve not gone too technical for you, Ian