Bob the Tech performed a total restoration of this Harmon/Kardon 430 Tuner including lamp replacements, power supply update, circuit board re-capping, and tuner alignment. The results are awesome, the unit looks great and sounds great.
Lamps
We found the original pointer lamp was burned out and the cabling had opened somehow, as shown in the first photo. Our replacement lamp fits perfectly. We also replaced the dial and signal strength fuse lamps. These were also burnt out or were broken (3rd photo). The final photo shows the result of the work, dial illumination looks great.
The stereo and power switch lamps were also burnt out. We replaced the stereo lamp with a new lamp. The first photo below shows the original stereo lamp, and the replacement prepped for installation. The last photos show the original power switch lamp, and the replacement as installed and operating. Removing the original is a chore because it was epoxied in place.
Power Supplies
We overhauled the main B+/- power supply (at left) with fresh capacitors and verified for operation. We also re-capped the lower voltage rectifier boards (center and right) with fresh capacitors, and verified. With the new power supply capacitors the unit will operate for years to come.
Board Recapping
Bob the Tech also replaced the electrolytic capacitors in power and signal path applications throughout the unit. The updated tone (left), phono EQ, tuner, and main amplifier boards (center, right) are below. We only had one hiccup through the entire process – the installation of a new electrolytic capacitor in reverse caused the FM Mute circuit to misbehave and we had no tuner output. An error in the drawing had us install a capacitor backwards, and the FM did not operate properly. The board markings indicate the opposite polarity, and when installed per the board markings all works great.
Tuner Alignment
Bob the Tech performed AM and FM Tuner alignment per the published procedures. Shown here is the adjustment of the MPX section 19kHz reference oscillator.
If your Harmon/Kardon 430 Tuner is in need of restoration or repair, contact Bob the Tech Audio.
