A while backed I picked up another HF Radio in on trade. A Kenwood TS-430S.
I sat the rig aside thinking the PLL was bad. Radio had no display, receive or transmit.
After going through a pair of Swan 500CX’s I decided I needed to start another project.
So pulled the 430 apart and started trouble shooting the display first. When I went to pull the display board I noticed that connector #3 on the display unit seemed very loose. As I unplugged the connector the whole socket came off the board. Wow I thought to myself. So after removal of the board I found more solder joints that were cracked. About a dozen and remember this board is only 3.5 by 1.75 inch.
Feeling I was sure this would solve the display problem I reinstalled the board and powered the rig up. Still no display….After checking voltages I found I was missing the 5 volt rail. Also found there was no 8 volt rail.
After reference to the schematic I found IC 8(5v) and IC 9(8v).
Removal of the IF board was fairly easy. This is the board that contains the voltage regulators. Turning the board over revealed the culprit. More cracked solder joints. Both IC’s were completely isolated from their pads.
I soldered them up and temporary installed the harness to check power. The 5 volt rail was at 3.2 volts. The 8 volt rail was around 6 volts. There are 2 electrolytic on the input and outputs of both regulators. What I found that all 4 caps had high ESR. Replaced these and reinstalled board. I now had a display and the mode buttons light up.
So made a great deal of progress on the old rig. Still have lots of other issues to address.
Receiver is way down.
No S-meter deflection until about 20k on the generator.
No transmit. But does produce a signal out.
Another issue is a broken diode I have to track down on the schematic. Should not be hard to do.
Sorry I did not get more pics while working on the boards. But the camara I had sux. So went o the local Trade it store and bought another one. I will be able now to take more pics as I move along with this repair.
I sat the rig aside thinking the PLL was bad. Radio had no display, receive or transmit.
After going through a pair of Swan 500CX’s I decided I needed to start another project.
So pulled the 430 apart and started trouble shooting the display first. When I went to pull the display board I noticed that connector #3 on the display unit seemed very loose. As I unplugged the connector the whole socket came off the board. Wow I thought to myself. So after removal of the board I found more solder joints that were cracked. About a dozen and remember this board is only 3.5 by 1.75 inch.
Feeling I was sure this would solve the display problem I reinstalled the board and powered the rig up. Still no display….After checking voltages I found I was missing the 5 volt rail. Also found there was no 8 volt rail.
After reference to the schematic I found IC 8(5v) and IC 9(8v).
Removal of the IF board was fairly easy. This is the board that contains the voltage regulators. Turning the board over revealed the culprit. More cracked solder joints. Both IC’s were completely isolated from their pads.
I soldered them up and temporary installed the harness to check power. The 5 volt rail was at 3.2 volts. The 8 volt rail was around 6 volts. There are 2 electrolytic on the input and outputs of both regulators. What I found that all 4 caps had high ESR. Replaced these and reinstalled board. I now had a display and the mode buttons light up.
So made a great deal of progress on the old rig. Still have lots of other issues to address.
Receiver is way down.
No S-meter deflection until about 20k on the generator.
No transmit. But does produce a signal out.
Another issue is a broken diode I have to track down on the schematic. Should not be hard to do.
Sorry I did not get more pics while working on the boards. But the camara I had sux. So went o the local Trade it store and bought another one. I will be able now to take more pics as I move along with this repair.