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Toshibaman |
Posted: Fri Apr 16, 2010 10:46 pm Post subject: RE: Toshiba 50H71 No video or sound!! Please help! |
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Hello. After reading the post and the replies, it sounds like you have a few problems to overcome with the TV. First issue, the No Video and No Sound. This is likely caused by the blown fuse F850, F851, or F852. One of these is the power line for the audio and video section on the main board and the others are convergence power fuses if I remember correctly. I would check them each with an ohm meter to see if they are open. Replace if needed as they should read a short across them (very low ohms). Next, we have the issue of the brightness and focus controls that may have been adjusted while you were turning knobs. Extra intensity of brightness while the convergence data is at a limit can cause the fuses to blow on this model. At this point, I would recommend turning the brightness down a bit (Not all the way thought) and read the service manual and find the service remote code to access the service mode in the TV. I can't quite remember it now as it has been a while. I know it is two buttons on the remote while pressing menu on the set. Something like mute, something, then the tv menu button. After you do this, then you can access the convergence touch up net with the remote and do a point to point touchup with your remote's directional buttons and save the results. The manual should explain this method. Lastly, you need to readjust the brightness or what technicians call the whiteline and whitebalance. The manual should explain methods to do this adjustment. If worst comes to worst, leave the white balance address settings as they are and turn up the brightness till you start to see retrace lines in the picture from excess brightness and then stop and turn it back down a 1/4 of the turn of the knob. It is a general good guess. If the convergence net will not move while adjusting then the convergence IC has opened or the convergence board itself will need replacement. You can also try soldering the connections on the bottom of the port and the jumpers mentioned earlier as it can only help. Hope this info helps you in some way. Thanks |
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minnie |
Posted: Fri Mar 27, 2009 10:20 pm Post subject: |
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http://www.matelectronics.com/
or
Ebay
Make sure you ask the if there good grade IC's, you don't want cheap ass Chinese knock offs. See if you can find some STK392-180's, their higher rated IC's. |
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Koveras |
Posted: Fri Mar 27, 2009 1:41 am Post subject: |
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Thank you so much minnie! I downloaded a complete service manual for my tv so I found the fuses and jumpers you suggested to be checked out and sure enough they are bad. I will replace these and the ICs and let you know how it goes. Can anyone suggest a good place to order these parts online? Thanks |
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minnie |
Posted: Thu Mar 26, 2009 10:16 pm Post subject: |
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If you look there are 2 jumpers on the side right board on the left side of the board. These are notorious for bad connections. Just resolder the 2 point on each jumper. Read
http://forum.eserviceinfo.com/viewtopic.php?t=34032 |
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Koveras |
Posted: Thu Mar 26, 2009 2:15 am Post subject: |
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Also I don't really have any tv repair experience but I do know how to solder pretty well. Is there a guide or something that can help me out? When you say solder the jumpers, do you mean solder them together? |
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Koveras |
Posted: Thu Mar 26, 2009 2:06 am Post subject: |
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Thank God, a reply from Minnie!!!! lol I will get right on checking those out and replacing them and let you know what happens! Any suggestions on a reputable place to get the parts? Thanks so much for your help! |
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minnie |
Posted: Thu Mar 26, 2009 12:01 am Post subject: |
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Check F850 & F852. Replace the convergence ic's and solder up jumpers 010 and 050. |
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Guest |
Posted: Wed Mar 25, 2009 4:52 pm Post subject: |
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Livewire, thank you for your reply. What should I be looking for? I have absolutely no experience in tv repair but I'm fairly handy with electronics. Does anyone have a guess at what it might be? |
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livewire |
Posted: Wed Mar 25, 2009 11:06 am Post subject: Equipment Repairs |
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You have to study the circuit of similar models better and see what best can be done.The fuses replacement may help...could not say whether positively. |
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Koveras |
Posted: Wed Mar 25, 2009 6:56 am Post subject: |
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Also thought I should add that when I turn on the tv the red power indicator light stays on like normal but if I get really close to the speaker I can hear a white noise coming out like a grounding problem or something. Also I was reading in another post and it seems a lot of people fixed there dead projection tvs by replacing c707 and e994 fuses. Is that only with Hitachi? I can't seem to find these parts on mine. Thanks for any help. |
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