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.

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Sidney
 
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Default 27" Hitachi tv model:TN-77000,chassis:G9LXU

27" Hitachi stereo tv model:TN-77000,chassis:G9LXU,year:Aug 1990
wooden cabinet (table top model,not a floor model)assembled in Point
Claire,Quebe,Canada.
The tv has HV,sound but no raster at all not even OSD after about few
minutes the picture comes in very dark,I increased the brightness on
the flyback but the retrace lines are barely visible,I replaced the
4.7 Uf,250v heater cap on the crt board which was fine but still dark
screen.The 3 guns are lit bright,I can download the free service
manual from:

http://www.hitachiserviceusa.com


but I would rather have a "quick answer" than to spend hours
troubleshooting,here are other models that share the same chassis:

GT-7881K
CT-7881
TE-67002

To familiarize you with this chassis here are some common parts:

CRT Panasonic # M68JUA98X (made in USA)
Flyback # 2435376 (location:T702)
Yoke # 2444251
IC401=LA4270 (sound o/p ic)
Q702=2SD1959
IC601=UPC1498H (vert o/p ic)

I looked at 5 or so repair tips sites but found no common repair tips
for such a chassis with such a problem,any have any tips for
me?.Thanks in advance.

Sidney
Dartmouth,Nova Scotia
Canada
http://www.herald.ns.ca/cgi-bin/home...+1019+Business
http://www.herald.ns.ca/stories/2002...ss126.raw.html
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Jerry G.
 
Posts: n/a
Default 27" Hitachi tv model:TN-77000,chassis:G9LXU

Check to see if the biases to the CRT guns are correct. Check the high
voltage, and the main power supply outputs. By your description, this
sounds like a weak CRT. Doing the proper checks will verify this.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
Instruments http://www.zoom-one.com/glgtech.htm
=========================================


"Sidney" wrote in message
om...
27" Hitachi stereo tv model:TN-77000,chassis:G9LXU,year:Aug 1990
wooden cabinet (table top model,not a floor model)assembled in Point
Claire,Quebe,Canada.
The tv has HV,sound but no raster at all not even OSD after about few
minutes the picture comes in very dark,I increased the brightness on
the flyback but the retrace lines are barely visible,I replaced the
4.7 Uf,250v heater cap on the crt board which was fine but still dark
screen.The 3 guns are lit bright,I can download the free service
manual from:

http://www.hitachiserviceusa.com


but I would rather have a "quick answer" than to spend hours
troubleshooting,here are other models that share the same chassis:

GT-7881K
CT-7881
TE-67002

To familiarize you with this chassis here are some common parts:

CRT Panasonic # M68JUA98X (made in USA)
Flyback # 2435376 (location:T702)
Yoke # 2444251
IC401=LA4270 (sound o/p ic)
Q702=2SD1959
IC601=UPC1498H (vert o/p ic)

I looked at 5 or so repair tips sites but found no common repair tips
for such a chassis with such a problem,any have any tips for
me?.Thanks in advance.

Sidney
Dartmouth,Nova Scotia
Canada
http://www.herald.ns.ca/cgi-bin/home...+1019+Business
http://www.herald.ns.ca/stories/2002...ss126.raw.html


  #3   Report Post  
Jerry G.
 
Posts: n/a
Default 27" Hitachi tv model:TN-77000,chassis:G9LXU

Check to see if the biases to the CRT guns are correct. Check the high
voltage, and the main power supply outputs. By your description, this
sounds like a weak CRT. Doing the proper checks will verify this.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
Instruments http://www.zoom-one.com/glgtech.htm
=========================================


"Sidney" wrote in message
om...
27" Hitachi stereo tv model:TN-77000,chassis:G9LXU,year:Aug 1990
wooden cabinet (table top model,not a floor model)assembled in Point
Claire,Quebe,Canada.
The tv has HV,sound but no raster at all not even OSD after about few
minutes the picture comes in very dark,I increased the brightness on
the flyback but the retrace lines are barely visible,I replaced the
4.7 Uf,250v heater cap on the crt board which was fine but still dark
screen.The 3 guns are lit bright,I can download the free service
manual from:

http://www.hitachiserviceusa.com


but I would rather have a "quick answer" than to spend hours
troubleshooting,here are other models that share the same chassis:

GT-7881K
CT-7881
TE-67002

To familiarize you with this chassis here are some common parts:

CRT Panasonic # M68JUA98X (made in USA)
Flyback # 2435376 (location:T702)
Yoke # 2444251
IC401=LA4270 (sound o/p ic)
Q702=2SD1959
IC601=UPC1498H (vert o/p ic)

I looked at 5 or so repair tips sites but found no common repair tips
for such a chassis with such a problem,any have any tips for
me?.Thanks in advance.

Sidney
Dartmouth,Nova Scotia
Canada
http://www.herald.ns.ca/cgi-bin/home...+1019+Business
http://www.herald.ns.ca/stories/2002...ss126.raw.html


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