Job Number

0204-47

Equipment type

Video Recorder

Maker + Model #

Akai VS-465EM

Made in

Japan

Comments

BAD

1

 No logic display

2

 Stops after 1 hours or so of playing

3

 No Fast Forward / Rewind

GOOD

1

 Good playback (sound and Picture)

2

 Good functioning and controls

Full repair description and observations

Fault 1: Logic Display

1

The first suspect was a bad voltage output from the power supply. The voltage to drive the display should be around -40 to -60V   

2

 There largest voltage output was found to be 26V, but the rectifying capacitor was rated to be 35V, so the voltage output was not to be expected to be higher from 32V. The expected voltage outputs were found from the internet, and all voltages were correct. Hence the power supply was not faulty.

3

 The voltage found on the terminals of the display was about -31V. This voltage supply was followed on the board and was found that they were been filtered /coupled by 2 100 uF capacitors (C447/C446) . These capacitors had a very suspected voltage on them – both terminals (-ve and +ve) were found -31V. There rating was just 25V. So the little voltage drop on them may be ok, howver I still had my suspects and decided to desolder and test them out.

4

 The circuit diagram was compact and great care had to be taken not to burn and damage the tracks with the solder tool. On testing the capacitors, one was found to give 20uF instead of 100uF. I replaced both capacitors, and the display worked perfectly.

Fault 2: No Fast Fow / Rewind

1

When FF or REW was pressed, the motor was heard to spin at high speed for 5 seconds and then it stops as the FF/REW function is stopped.

2

On inspecting the FF and Rew mechanism, it consisted of a complex gear & shuttle mechanism. When FF and REW was pressed, a lever pushes the shuttle in, and causes the activation of the FF/Rew idler gear. Once activated this gear is responsible to make the FF and REW to operate

3

There was a black cube-shaped plastik blocking this mechanism. Initially it was thought that it was part of the mechanism but then it was concluded that it was alien nad it was a broken pasrt from somewhere lese in the plastic chasis, probably the cassette loading.

4

When this plastik was removed, the FF & REW came to operate well.

Fault 3: Sometimes play stops after 1 to 2 hours without reason

1

First suspect was the power supply, but it was hard to confirm it. Then it was noted that sometimes the tape gets blocked at the pinch roller area and causes the cassette to stop. The pinch roller and the shaft (which appeared to have rusty deposits) was cleaned with alcohol

2

The tape blocking sysmptom was reduced very much, and on several testing on different cassettes, the video did not stopped else then once.  The video was tested for about 20 hours before handing it back to the user.

Repair summary

1)       Display fault: Abut 20 hours of video playing was  C446 & C447 low capacitance

2)       Loss of REW/FF fault: Probably a piece of alien plastic blocked the mechanism

3)       Stop after 1 hour fault: Probably dirt in pinch rolelr and shaft that caused the tape to block and hence stop the operation

Precautions, fouls and advises

1

Once, the cassette was blocked and a little extra force had to be used to bring it free. This  caused a part of the cassette loading tray to break! On inspection it was noted that this pieace of broken plastic was previously broken and fixed by super glue by a previous technician. Hence it is very important to handle everything with care as you can’t say hidden defects / faults the item may have.

1

Voltage supply output voltages (approx values): These vary slightly depend operation mode of video (Standby, stop, play, etc)

Pin 1

25V

Pin 2

17V

Pin 3

14V

Pin 4

9V

Pin 5

9.5V

Pin 6

0 (Gnd)

Pin 7

5V

Pin 8

5.5V