Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 10
Default VCR won't record or playback color

A portable Beta VCR from 1985 works perfectly except there is no color:

1. Pre-recorded color tapes play back in B&W
2. Tapes recorded on this VCR play back in B&W on this VCR
3. Tapes recorded on this VCR play back in B&W on other known good VCRs

Therefore, the VCR can neither record nor playback color signals. What
is the most likely cause?

Is it the 3.58 MHz oscillator, the comb filter, the color killer, or
lack of a color burst? Or, is it just a defective transistor or IC that
contains an internal B&W/color switch?

Thanks

  #2   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 24
Default VCR won't record or playback color


"VCR Gymnast" wrote in message
oups.com...
A portable Beta VCR from 1985 works perfectly except there is no color:

1. Pre-recorded color tapes play back in B&W
2. Tapes recorded on this VCR play back in B&W on this VCR
3. Tapes recorded on this VCR play back in B&W on other known good VCRs

Therefore, the VCR can neither record nor playback color signals. What
is the most likely cause?

Is it the 3.58 MHz oscillator, the comb filter, the color killer, or
lack of a color burst? Or, is it just a defective transistor or IC that
contains an internal B&W/color switch?

Thanks


My guess would be the 600kHz3.58MHz conversion circuits. Do u have a
schemo for this unit and what kind of test signals are u capable of
injecting?


  #3   Report Post  
Posted to sci.electronics.repair
b b is offline
external usenet poster
 
Posts: 764
Default VCR won't record or playback color


VCR Gymnast ha escrito:

A portable Beta VCR from 1985 works perfectly except there is no color:

1. Pre-recorded color tapes play back in B&W
2. Tapes recorded on this VCR play back in B&W on this VCR
3. Tapes recorded on this VCR play back in B&W on other known good VCRs

Therefore, the VCR can neither record nor playback color signals. What
is the most likely cause?

Is it the 3.58 MHz oscillator, the comb filter, the color killer, or
lack of a color burst? Or, is it just a defective transistor or IC that
contains an internal B&W/color switch?

Thanks


Today I fixed a sony vhs with this symptom. e-e pic ok, tapes no
colour, as you describe. had to resolder a bit in the y/c section and
replaced several 1uF caps and the 4.43 xtal for good measure.
-B.

  #4   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 931
Default VCR won't record or playback color

"VCR Gymnast" wrote in news:1152157251.328327.300970
@a14g2000cwb.googlegroups.com:

A portable Beta VCR from 1985 works perfectly except there is no color:

1. Pre-recorded color tapes play back in B&W
2. Tapes recorded on this VCR play back in B&W on this VCR
3. Tapes recorded on this VCR play back in B&W on other known good VCRs

Therefore, the VCR can neither record nor playback color signals. What
is the most likely cause?

Is it the 3.58 MHz oscillator, the comb filter, the color killer, or
lack of a color burst? Or, is it just a defective transistor or IC that
contains an internal B&W/color switch?

Thanks


Have you tried cleaning the heads? We had one that went to black and
white and cleaning the heads made it come back to color part way.

Puckdropper
--
Wise is the man who attempts to answer his question before asking it.

To email me directly, send a message to puckdropper (at) fastmail.fm
  #5   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 280
Default VCR won't record or playback color

VCR Gymnast wrote:
A portable Beta VCR from 1985 works perfectly except there is no
color:

1. Pre-recorded color tapes play back in B&W
2. Tapes recorded on this VCR play back in B&W on this VCR
3. Tapes recorded on this VCR play back in B&W on other known good
VCRs

Therefore, the VCR can neither record nor playback color signals. What
is the most likely cause?

Is it the 3.58 MHz oscillator, the comb filter, the color killer, or
lack of a color burst? Or, is it just a defective transistor or IC
that contains an internal B&W/color switch?

Thanks


Make sure there isn't a color / bw switch somewhere, like on the back panel.
Seen it on U-Matics, anyway...

Mark Z.




  #6   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 10
Default VCR won't record or playback color


Puckdropper wrote:
"VCR Gymnast" wrote in news:1152157251.328327.300970
@a14g2000cwb.googlegroups.com:

A portable Beta VCR from 1985 works perfectly except there is no color:

1. Pre-recorded color tapes play back in B&W
2. Tapes recorded on this VCR play back in B&W on this VCR
3. Tapes recorded on this VCR play back in B&W on other known good VCRs

Therefore, the VCR can neither record nor playback color signals. What
is the most likely cause?

Is it the 3.58 MHz oscillator, the comb filter, the color killer, or
lack of a color burst? Or, is it just a defective transistor or IC that
contains an internal B&W/color switch?

Thanks


Have you tried cleaning the heads? We had one that went to black and
white and cleaning the heads made it come back to color part way.


I cleaned the heads both manually and with a Scotch cassette cleaner,
but no improvement. Video remains B&W.


Puckdropper
--
Wise is the man who attempts to answer his question before asking it.

To email me directly, send a message to puckdropper (at) fastmail.fm


  #7   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 10
Default VCR won't record or playback color


Mark D. Zacharias wrote:
VCR Gymnast wrote:
A portable Beta VCR from 1985 works perfectly except there is no
color:

1. Pre-recorded color tapes play back in B&W
2. Tapes recorded on this VCR play back in B&W on this VCR
3. Tapes recorded on this VCR play back in B&W on other known good
VCRs

Therefore, the VCR can neither record nor playback color signals. What
is the most likely cause?

Is it the 3.58 MHz oscillator, the comb filter, the color killer, or
lack of a color burst? Or, is it just a defective transistor or IC
that contains an internal B&W/color switch?

Thanks


Make sure there isn't a color / bw switch somewhere, like on the back panel.
Seen it on U-Matics, anyway...


There is no external BW/Color switch. This switch is present inside an
IC somewhere in the chroma circuit, which is a separate module in this
very small modular VCR. Even though this VCR is a Beta from 1985, it is
the smallest VCR ever made.


Mark Z.


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Can I Record Audio onto the Video Tracks of my VHS Video Recorder? Gazza Electronics Repair 18 January 16th 05 03:29 PM
color camcorder lost color recording capability JVC GR-C7U Arvis N. Electronics Repair 4 August 31st 04 04:16 AM
Sony CCD-FX520 camcorder - no color on playback Ken_B Electronics Repair 1 August 14th 04 05:02 AM
Yet another tub caulking question (sorry!) -this time about color MAG Home Repair 1 August 2nd 04 03:52 AM


All times are GMT +1. The time now is 09:05 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"