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Toshiba vcr model:M-671C

Toshiba 4 head hi-fi stereo vcr model:M-671C,year:Aug 1995,CSA File
No:LR94373.No power the secondary dc voltages of the SMPS power supply
are lower than they should be,I don't have an ESR meter but I decided
to replace all electrolytics in the power supply:

Primary:

C812=100 Uf,25v
C813=10 Uf,50v

Secondary:

C821=220 Uf,10v
C828=1000 Uf,16v
C823=10 Uf,50v
C832=470 Uf,25v
C822=470 Uf,25v
C826=47 Uf,50v
C829=47 Uf,50v
C833=47 Uf,50v

I also checked & replaced Q801=BUL26XI and checked the diodes and
resistors in the SMPS power supply section but still the secondary
voltages are lower,I did clean the mode switch.For a picture of the
chassis see below:

http://studiosoundelectronics.com/images/48ChsTop.jpg
http://www.studiosoundelectronics.com/Images/48ChsBot.jpg

Since I could not find a schematic,here are the voltages taken (note
the smps xfmr squeals at low level):

C826=13v
C828=6v
C832=9v
C822=17v
C821=-19v
D831=0.4v
C823=-13.3v

I unsoldered smps's secondary diodes one at a time and still same
problem except when I unsoldered the diode for C826 the voltage at all
the other diodes rose and no more smps squeal but still no power,I have
checked many components.
Anyone have any common repair tips? So if anyone could look up repair
tips at these pay sites:

http://www.Euras.com
http://www.winstip.com
http://www.repairhelper.com
http://www.shophelper.com
http://www.circuitwork.com/techassist/cgi-bin/yabb/YaBB.cgi
http://www.network54.com/Forum/27725
http://www.nesda-ohio.com
http://www.anatekcorp.com

or any other pay sites,also if any is ASC for Toshiba or RCA as some
RCA vcr's used this chassis.Thanks in advance for help.

Sidney
Dartmouth,Nova Scotia
Canada

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K

Ken G.

Jan 1, 1970
0
You can get a good working VCR these days for between free and 50$ .
Many areas have salvage store return type stores that have new ones for
35$ or so .
 
A

antdes45

Jan 1, 1970
0
It depends if the VCR is worth it, like my M-5900C VCR, which is an old
Stereo Hi-Fi 4 Head 198(8?) dubbing VCR. The mechanics work perfectly
and the electronics never failed. It has features new VCRs don't
have(VU meter, vol adj., MIC inputs), and pretty good play/rec
picture/sound. It weighs a ton and electronics take 5/8 of the place. 1
of the 3 giant PCBs alone is 500$. I guess a service manual would be
really useful in my case.

Ken G. a écrit :
 
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