View Single Post
  #5   Report Post  
Posted to sci.electronics.repair
[email protected] adnankanaan1961@gmail.com is offline
external usenet poster
 
Posts: 4
Default Pioneer Amp Problem

VERY IMPORTANT NOTE
1-if the amp is falling inside and the plastic plate is broken edges where screws goes in from the back side try to put it back in place and drilling new holes for the screws to hold back in its place and BE SURE THAT THE 2 HEAT SINKS of the transistors upper part is not touching the lower part to prevent short circuits between transistors (cable tie or isolated copper cables by tying them separately to the back plastic plate through vent holes)..
2-support the amp by using metal strip fixed internaly above the amp on the back of the case to the vent fan (there is an plastic arm on top of the fan where you can fix the other end of the metal strip) I use a slot metal cover from old pc and works well for the size and length this way will support the weight of the amp and prevent it ftom falling back inside .
3-MOST IMPORTANT ISSUE is to disable the high voltage from the main power transformer output that generate hi voltage to the amp (no more need for this hi voltage) by desoldering the 3 pins marked as MAIN on the output board of the main power transformer and be sure to discharge the hi voltage that connected to the old amp (grey ribbon cable) marked as -B +B can be discharged by connecting those cables to a 70 watt lamp CARFULLY THEY CONSIST HIGH POWER FROM THE 2 GIANT CAPS and then isolate those cables and leave them disconnected from the old amp.
This procedure must be taken before installing the above mentioned process
Good luck