I've noticed something more & more here lately that appears to be sort of putting the horse before the cart. It appears that many are ordering a flyback repair kit from the get go when their K7000 chassis is dead. The power supply should be checked first as it is very common to have voltage surges short one of the bridge rectifiers, especially during springtime thunderstorms.
 The first step should be to ohm out the diodes that comprise the bridge above... D19, D20, D21 & D22. If any one of them is shorted it can be replaced with a 1N4007. You'll need to check R103, a 2.7 ohm 7 watt resistor, as it will likely be open, as well.  R103 is the large resistor above that is mounted vertically in a metal stand. If it is open & needs to be replaced you'll need an exact 2.7 ohm 7 watt replacement. Many of you ask for one with a metal cage around it, but all you need is the resistor itself, which you can change out on the metal stand. Another component in the B+ power supply above is the filter C55... a 560uf200v cap. A frequently asked question pertaining to the B+ filter is does it come in a typical cap kit. The simple answer is no. The main reason that B+ filters are not included in any sort of cap kits on the market is that it would make them cost prohibitive for a shotgun type repair. These filters are usually still good & they really ham it up when bad with unmistakable symptoms such as the postage stamp pic, violent weaving of the pic or the proverbial black bar rolling thru the pic. Happy Gaming.... |