End of the 70ies and during the 80ies Sharp was known for their big and powerful ghettoblasters. I remember a lot of different types in the “GF” series, for example the huge GF-777.
But then in the 90ies they more or less disappeared from this "Portable Audio " market. They then more focussed on development of LCD TV's.
However, at least in Japan Sharp tried to start into the beginning “Bubble Boombox” era. End of 1990 they introduced two devices, that probably should compete with Panasonic’s RX-DT7/-DT9 or AIWA’s CSD-SR7/SR8 – the Sharp QT-88CD and the smaller, less featured QT-77CD.


The bigger QT-88CD never was offered outside of Japan. Only the smaller QT-77CD came into the western world – as CD-S77.
Recently I could catch a QT-88CD for very low price directly from Japan.
It arrived as usual – quite dirty and with a rotten battery compartment. Only radio was working, no CD and no tape deck.

After a deep cleaning I started the failure root causes investigation. Fortunately, as often for such old defective devices, it were almost only mechanical issues.
On the right tape deck the left reel did not turn. I found, that the retaining ring on the reel wheel got lost. So the reel slid forward and lost connection to the gear.
On CD player the CD was not spinning. The reason was, that the rubber ring on the spindle motor, that lifts the CD a little bit and gives grip, had disappeared.
Furthermore, a lot of the micro switches did not work anymore.
The retaining rings and the micro switches I ordered online and for the rubber ring I took a sealing ring for water pipes, that had the right diameter. I just had to grind it down to a lower height.

Of course also both tape deck belts had to be replaced.
At his occasion I added LED lights int o the tape decks and the CD player.


After all was repaired, I put it together and gave it some polish.
Now everything works again. With the “Active Servo Technology”, that actually was invented by Yamaha, it gives a powerful sound. Interesting thing is, that the big display with its spectrum analyzer is illuminated even when the device is operated with batteries. On most other boomboxes backlight works only when connected to the mains.





Here it is to see and listen in action:
Sharp QT-88CD
Later I also ordered the according remote control. The volume knob is motor driven. After the long time not in use it needs a drop of oil, as it make some noise.
Even in battery operation with the remote the Sharp can be set into standby and awoken again.
With Remote Control
But then in the 90ies they more or less disappeared from this "Portable Audio " market. They then more focussed on development of LCD TV's.
However, at least in Japan Sharp tried to start into the beginning “Bubble Boombox” era. End of 1990 they introduced two devices, that probably should compete with Panasonic’s RX-DT7/-DT9 or AIWA’s CSD-SR7/SR8 – the Sharp QT-88CD and the smaller, less featured QT-77CD.


The bigger QT-88CD never was offered outside of Japan. Only the smaller QT-77CD came into the western world – as CD-S77.
Recently I could catch a QT-88CD for very low price directly from Japan.
It arrived as usual – quite dirty and with a rotten battery compartment. Only radio was working, no CD and no tape deck.

After a deep cleaning I started the failure root causes investigation. Fortunately, as often for such old defective devices, it were almost only mechanical issues.
On the right tape deck the left reel did not turn. I found, that the retaining ring on the reel wheel got lost. So the reel slid forward and lost connection to the gear.
On CD player the CD was not spinning. The reason was, that the rubber ring on the spindle motor, that lifts the CD a little bit and gives grip, had disappeared.
Furthermore, a lot of the micro switches did not work anymore.
The retaining rings and the micro switches I ordered online and for the rubber ring I took a sealing ring for water pipes, that had the right diameter. I just had to grind it down to a lower height.



Of course also both tape deck belts had to be replaced.
At his occasion I added LED lights int o the tape decks and the CD player.




After all was repaired, I put it together and gave it some polish.
Now everything works again. With the “Active Servo Technology”, that actually was invented by Yamaha, it gives a powerful sound. Interesting thing is, that the big display with its spectrum analyzer is illuminated even when the device is operated with batteries. On most other boomboxes backlight works only when connected to the mains.





Here it is to see and listen in action:
Sharp QT-88CD
Later I also ordered the according remote control. The volume knob is motor driven. After the long time not in use it needs a drop of oil, as it make some noise.
Even in battery operation with the remote the Sharp can be set into standby and awoken again.
With Remote Control