Recently acquired a KR-7600 Receiver that will need the power supply boards rebuilt, and I'm somewhat confused by the diodes on the X00-1770-10 Power Supply Board "A".
Dk1 is listed in the SM as EQA01-24R a 24v Zenor Diode. Crosses to a 1N5252B. What is installed is 2458R which is black and doesn't look like other zenor diodes I have seen. It appears to be the original factory part.
Dk2 is listed in the SM as YZ140 a 14v Zenor Diode. Crosses to 1N5244B. This looks like a typical glass orange Zenor with black band, and appears to be the original factory part. I have not pulled it to look at the markings.
Dk3 is listed in the SM as EQA01-24R a 24v Zenor Diode, same as Dk1. Crosses to 1N5252B. This looks like a typical glass orange diode with black band, but nothing like Dk1. By looking at the foil side solder, this may well have been changed out at some point. I have not pulled it to look at the markings.
Dk4 is listed in the SM as 1S2076 a switching diode that crosses to a 1N4148. This looks like a typical glass orange zenor with light blue band, but evidently is not a Zenor Diode. Appears to be the original factory part. I have not pulled it to look at the markings.
Qk1 has the typical hot spot darkened area on the board.
Qk5 has also been quite hot and the board is darkened around it.
The receiver powers up and relay pulls in pretty quickly at 1.5 to 2 seconds. Seems a little quick.
Receiver seems to play fine, but have only tested briefly. I want to get the power supply boards squared away before I test heavily.
X00-1770-10 Power Supply "A" Voltages
Pin 1: +52.4 VDC
Pin 2: +23.8 VDC
Pin 3: +15.9 VDC
Pin 5: -23.9 VDC
Pin 6: -53.0 VDC
Pin 7: -5.0 VDC
Pin 12: +23.8 VDC
I cannot read what the correct voltages should be on the schematic.
Can someone help me sort this out with the correct diode parts and locations on the power supply boards.
I think I have a handle on the transistors and capacitors.
Will change capacitors and diodes on X00-1790-10 "C" board but leave Dr4 S2HB-20 alone unless it checks defective.
Thanks for the help. Jim
Dk1 is listed in the SM as EQA01-24R a 24v Zenor Diode. Crosses to a 1N5252B. What is installed is 2458R which is black and doesn't look like other zenor diodes I have seen. It appears to be the original factory part.
Dk2 is listed in the SM as YZ140 a 14v Zenor Diode. Crosses to 1N5244B. This looks like a typical glass orange Zenor with black band, and appears to be the original factory part. I have not pulled it to look at the markings.
Dk3 is listed in the SM as EQA01-24R a 24v Zenor Diode, same as Dk1. Crosses to 1N5252B. This looks like a typical glass orange diode with black band, but nothing like Dk1. By looking at the foil side solder, this may well have been changed out at some point. I have not pulled it to look at the markings.
Dk4 is listed in the SM as 1S2076 a switching diode that crosses to a 1N4148. This looks like a typical glass orange zenor with light blue band, but evidently is not a Zenor Diode. Appears to be the original factory part. I have not pulled it to look at the markings.
Qk1 has the typical hot spot darkened area on the board.
Qk5 has also been quite hot and the board is darkened around it.
The receiver powers up and relay pulls in pretty quickly at 1.5 to 2 seconds. Seems a little quick.
Receiver seems to play fine, but have only tested briefly. I want to get the power supply boards squared away before I test heavily.
X00-1770-10 Power Supply "A" Voltages
Pin 1: +52.4 VDC
Pin 2: +23.8 VDC
Pin 3: +15.9 VDC
Pin 5: -23.9 VDC
Pin 6: -53.0 VDC
Pin 7: -5.0 VDC
Pin 12: +23.8 VDC
I cannot read what the correct voltages should be on the schematic.
Can someone help me sort this out with the correct diode parts and locations on the power supply boards.
I think I have a handle on the transistors and capacitors.
Will change capacitors and diodes on X00-1790-10 "C" board but leave Dr4 S2HB-20 alone unless it checks defective.
Thanks for the help. Jim