TechwalcottCBSales Posted September 9, 2006 Share Posted September 9, 2006 I'm not sure what's the difference between the 1N47A and the 1N47 is... The 'a' at the end indicates the first improvement done to this diode since it was first manufactured. A 'b' would indicate a second improvement and so on. Ty http://walcottcb.com http://walcottcb.com'> Quote Link to comment Share on other sites More sharing options...
TechwalcottCBSales Posted September 9, 2006 Share Posted September 9, 2006 The IRF740 is a Mosfet N Channel Transistor. N-channel power MOSFET, 10 A, 400V. in 3-pin TO-220AB package. Operational temperature range from -55°C to 150°C. When you look at the front of the Transistor with the legs pointing down. From left to right the legs are Gate, Drain and Source. My guess they are using this as a power amplifier. I have 1 channel out of my amp, but have yet to open it. Without a schematic I'll have to look at the circuitry and figure out what the transistor is used for. I'll post any info I come up with. Ty http://walcottcb.com Quote Link to comment Share on other sites More sharing options...
TechwalcottCBSales Posted September 9, 2006 Share Posted September 9, 2006 The hissing sound could be from a failed rectifier. I noticed a prominent AC signal present after the rectifier on my unit. I also noticed similar problems with the overheating of R12 and R26. This could also be from a leaky or failed Rectifier. I am still trying to find a replacement bridge rectifier. Probably one that is rated higher. The only cross that I have is NTE, which I would prefer not to use NTE replacement parts because of their reputation as using subpar chinese work enviroment standards. WIll try to keep ya's posted as I find more information. Ty http://walcottcb.com P.S. We only service 10 or 11 meter 2 way radio equipment at our store. If anyone was wondering. [] Quote Link to comment Share on other sites More sharing options...
TechwalcottCBSales Posted September 10, 2006 Share Posted September 10, 2006 I found a replacement Bridge Rectifier from Mouser. I haven't yet ordered it, but I am going to try the higher amperage rated version. http://www.mouser.com/search/ProductDetail.aspx?R=RS803virtualkey58300000&Mpc=Rectron Rectifiers - Bridge&Mpcn=58301 is the higher rated replacement. http://www.mouser.com/search/ProductDetail.aspx?R=RS606virtualkey58300000&Mpc=Rectron Rectifiers - Bridge&Mpcn=58301 is the orginal replacement part. It's going to take me a couple weeks to get the part in. I have to make a list of other parts I need before I order, heh. Ty http://walcottcb.com Quote Link to comment Share on other sites More sharing options...
stpete cooling Posted September 14, 2006 Share Posted September 14, 2006 The IRF 740 is used as part of the switching power supply in the Promedia 5.1 systems. I am not familiar yet with the 4.1, but I see a familiar miniboard in the photo; Indigo's BASH design uses it to quickly adjust (via an IRF 740) the supply voltage to the amplifiers based on the load. Quote Link to comment Share on other sites More sharing options...
tinker Posted October 2, 2006 Share Posted October 2, 2006 You said R12 was 680 ohm, how could you tell? Mine mine got so hot I can't read the color bands. It reads 640 ohms (Off the PCB) on the ohms meter. I assume you mean the R12, Z1 combo on the 610036 board. The R26 that I have that got hot is on the 640014 board and I can't read the bands on that one either. It reads 50.9 Kohms (Off the PCB) on the ohms meter. Never mind, Klipsch tech confirmed those are the right values. Sorry Quote Link to comment Share on other sites More sharing options...
Andy W Posted October 24, 2006 Share Posted October 24, 2006 I'm not sure what's the difference between the 1N47A and the 1N47 is... The 'a' at the end indicates the first improvement done to this diode since it was first manufactured. A 'b' would indicate a second improvement and so on. Ty The "A" in a zener diode's part number stands for 10% tolerance. "B" would be 5% tolerance, and so on... Quote Link to comment Share on other sites More sharing options...
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