Wednesday, May 22, 2013
Friday, August 6, 2010
The two spindle assemblies are taken apart. The 700ZXL is interesting as it has a variation on the transport mechanism. At it uses a digital counter, the deck needs some way of sensing movement and direction. There is the motion sensor found on all other decks which is powered by a long belt from the take up spool to a small light and wheel assembly. But this only allows the deck to sense movement. Both forward and reverse direction appears the same.
Nakamichi did something interesting with the other spindle by fitting this assembly on it. Two light sensors are placed side by side on one side of a wheel. the other side has a small bulb. By sensing the order of which sensor triggers first, the deck now knows which way the tape is moving.
This takes care of getting the digital counter to index in the right direction - interesting!
This assembly is removed, along with the rest of the spindle parts. With both spindles removed, all that remains in now the brake assembly and little else. Time for a good cleaning!
Above, you can see the transport with most of the assemblies stripped. The digital counter mechanism is mounted back for picture taking. The entire mechanism is carefully checked, and cleaned away of dust, dirt and grease.
Once all the dirt and old lubricants are cleaned away, the base is ready and kept away. Attention now turns to the various sub-assemblies. But before that, it is time to catch some important shows and have some rest.
Sunday, July 25, 2010
Stay tuned for from Nakamichi action...
Friday, February 6, 2009
The assembly consists of two sleeve bearings inserted at both ends of a cast metal holer. First the bearing is checked visually and everything is in good shape. Swabbing with cotton buds and alcohol does not show any dirty lubricant. The assembly is then inserted into a oven. Heat is then slowly and carefully applied to the joint to ensure that expansion is as linear as possible.
Next the assembly is immersed in solvent (like common paint thinner in an open ceramic or glass bowl) and then set back into the over at a lower temperature of about 130~150 degrees Celsius.
Thursday, January 22, 2009
You can see the line where the flywheel was out of the solution and the difference prior to the treatment.
The second flywheel was also cleaed and buffed. Both flywheels were checked carefully for any dings, scratches, marks or flat spots. Some pitting was still present but these will not affect the belt or performance and it is best to leave them as they are. The resulting surface is much smoother at has the right surface to give the driving belt a good grip.
The flywheels are ready to literally roll!
Now its time to move on to the rest of the transport...but first to get some sleep!
Monday, January 19, 2009
The motor spindle which drives the idler is corroded! Some cleaning with solvent does not seem to help, so this needs to be fixed.
Thursday, January 15, 2009
The leaked acid also damaged the solder pad of most components, so m
Here is more soldering with close components. The center row of components are transistors and heat is applied carefully to these.
This section shows soldering done underneath two ICs. The wiring was very close and have to be cleaned and checked.
The wiring was finally complete. No glue or solvent was used to hold the wires down. Now all that remains is to power up the board. However, before setting the board back inside the actually deck, I want to check the board seperately. What are the possible ways to make the board work seperately?