Riddled TV Repair Forum
Service Menu and Manual Schematics
 
   
 FAQFAQ   SearchSearch   RegisterRegister 
   Log inLog in 
Toshiba CF30F40R No vertical   Goto page 1, 2, 3  Next  
Post new topic   Reply to topic    Riddled TV Repair Forum Index -> TV Repair
 
Author Message
chumba



Joined: 01 Jul 2009
Posts: 66

PostPosted: Mon Dec 06, 2010 9:30 am    Post subject: Toshiba CF30F40R No vertical Reply with quote

Have a Toshiba CF30F40R, chassis TAC 9632 with just a thin horizontal line. Resoldered the IC connections and other local parts but still problem exists.
If I bang hard on either side of the cabinet the full screen sometimes comes back, but then reverts back to the thin line a few minutes later. Before this problem started, I noticed the vertical was jumping a bit on the bottom of the screen. Please help. Thx Rolling Eyes
Google

PostPost subject: Advertisement

kuhurdler



Joined: 28 Dec 2006
Posts: 2855
Location: Overland Park, KS

PostPosted: Mon Dec 06, 2010 10:09 am    Post subject: Reply with quote

if you can get it to come back by banging on it, its definitely a broken circuit trace somewhere. Get a bright light and a magnifying glass, and start soldering everything
sdtv



Joined: 31 Mar 2008
Posts: 12

PostPosted: Sat Dec 11, 2010 8:37 pm    Post subject: Reply with quote

Sometimes the bad connection is the yoke connector where the wires are crimped.

Try wiggling the connector where it plugs into the main board.
chumba



Joined: 01 Jul 2009
Posts: 66

PostPosted: Fri Dec 17, 2010 6:26 pm    Post subject: Reply with quote

I resoldered all the connections but still same problem exits, except that now the full screen does not appear after banging on the side.
Would the vertical IC be part # STR-Z4151? It is a 14 pin chip with a large heat sink and a separate clip onto the heat sink. Could not find any data sheets on it.
JTS1957



Joined: 21 Jan 2009
Posts: 2325
Location: Far, Far Away

PostPosted: Fri Dec 17, 2010 7:12 pm    Post subject: Reply with quote

TA8427 check solder joints first.
Check electrolytic caps in that same area. Their location numbers should start with the same "hundreds" series. Look for one in the 100ufd to 220ufd range especially.
Google

PostPost subject: Advertisement

chumba



Joined: 01 Jul 2009
Posts: 66

PostPosted: Sun Jan 16, 2011 8:16 pm    Post subject: Reply with quote

Thanks for the vertical IC part number...now that I'm in the correct section of the board, I resoldered everything in the 300 number section (the IC is Q301). I ohmed out all 7 pins of this IC to their next point and all tested good, so doesnt appear to be broken PCB traces. Also disconnected and reconnected the yoke and PCB connectors. Also tried adjusting the "Screen" control a bit.
The only electrolytic cap in this section is C320=100mfd. Swapped it out but problem persists after all the above.
JTS1957



Joined: 21 Jan 2009
Posts: 2325
Location: Far, Far Away

PostPosted: Sun Jan 16, 2011 9:36 pm    Post subject: Reply with quote

Have you tried swapping out the IC?
chumba



Joined: 01 Jul 2009
Posts: 66

PostPosted: Tue Jan 18, 2011 11:54 am    Post subject: Reply with quote

No, haven't swapped out the IC, would have to buy a new one. What else should I try 1st? How about the other non electrolytic caps and/or resistors and/or diodes in the same section of location numbers?
JTS1957



Joined: 21 Jan 2009
Posts: 2325
Location: Far, Far Away

PostPosted: Tue Jan 18, 2011 5:03 pm    Post subject: Reply with quote

Most others seldom fail.

Other than posting the voltages on all IC pins, I can't think of anything else you should do.
chumba



Joined: 01 Jul 2009
Posts: 66

PostPosted: Sun Mar 27, 2011 2:45 pm    Post subject: Reply with quote

After sniffing around some more, found that 500mA Fuse F301 was blown. However I replaced the fuse and it immediately blew.
Display posts from previous:   
Post new topic   Reply to topic    Riddled TV Repair Forum Index -> TV Repair All times are GMT - 6 Hours
Goto page 1, 2, 3  Next
Page 1 of 3

 


Disclaimer: All information provided by RiddledTV is strictly for information purposes only. Please observe all warnings displayed on your electronic
devices. This information should only be used to help diagnose work, and all service should be performed by a qualified technician.
Contact Us       Privacy Policy       Copyright © 2015 RiddledTV.com       Advertise on RiddedTV.com