Some people believe that the Kenwood KT-917 is the finest FM tuner that was ever manufactured. This is truly the cream of the crop. Pulse Count Detector, high build quality, Made in Japan.
A fellow in my community decided to trade-in this KT-917 for some quality tube audio gear. He had his eye on some nice tube gear in my collection, and his KT-917 needed repaired for quite a long time. Since he was currently more enthused with rediscovering his music tastes (vinyl and CD), he decided to forego repair and trade for tube gear.
Repairing the KT-917 was straightforward. The tuner was not decoding, and some quick troubleshooting revealed a defective MC1496 IC, which is a Balanced Modulator-Demodulator designed for FM detection.
Luckily, I had a few NOS-NEW MC1496 in my parts stock, so it was off to work.
The most difficult aspect of the repair (apart from diagnosis) was lifting the board in question. The Kenwood is all directly wired, which means that there are no harnesses to easily disconnect a board from the others. Luckily, I was able to lift this board enough to work on it by only disconnecting three wires.
Once the board was lifted, the MC1496 IC needed to be carefully pulled to avoid damaging the traces on the board. I use a pointed solder iron tip, low heat, and remove all solder from the joints. That is still not sufficient to pull the IC, so next I cut all the leads on the old defective IC, which allows me to pull each lead individually.
Next, the new IC is carefully inserted, making sure that the leads are aligned correctly. It is easy to make a mistake with these old round IC packages.
Carefully solder, double-check all leads to make sure that no solder overflowed onto an adjacent pin, and reassemble. Do not forget to reattach the three wires that were removed to lift the board.
Replace the chassis covers, hook it up to your amp and antenna, and ENJOY what may be the finest FM listening that the world has to offer!
Additional Photos: [Click Thumbnails to enlarge]FM Stereo Tuner | For Sale | Japan | Kenwood | KT-917 | MC1496 | Pulse Count Detection | repair