Home |
Search |
Today's Posts |
|
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 | Display Modes |
#1
|
|||
|
|||
Toshiba Projection TV Help.
I have a Toshiba model TP5580A projection TV that was given to me by a
friend. This is a older unit manufactured in 1992. I was told the picture was blurry so I cleaned the lenses and the mirror before plugging it in and the picture is nice and bright and crisp believe it or not. But when I turn it on there is a horizontal line in the center of the TV. It looks like the picture is getting sucked into the line. After it warms up for about 5 minutes the line moves upward about 12 inches above center and becomes very faint. At this point nothing is being sucked into it anymore and it is just a couple of small faint lines. You can only see the lines when the TV has a light picture on it. Anyway most people don't even see the lines at this point but it is driving me crazy. I have never worked on a projection TV before but I do repair arcade monitors on a regular basis. Based on my experience with arcade monitors I would think the problem lies with the horizontal output transistor either starting to go bad or a cold solder joint. But I do not have any schematics or service manual to work from. Unlike an arcade monitor which has one circuit board this has several pcb's as well as 3 crt's. Can anyone point me in the right direction or better yet tell me where I can obtain a service manual and schematics, preferably in adobe acrobat format. I have been searching google for the last 2 days in my free time looking for anything related to this issue and found nothing. I did see many posts about fluid leaking out onto the boards causing a variety of problems but nothing like this. Thanks, in advance Pat |
#2
|
|||
|
|||
Toshiba Projection TV Help.
If the service manual is still available, you need to buy it from any
Toshiba authorized parts dealer. Toshiba has a pretty strict policy of only selling service information to servicers for what they call legal liability issues. As to your problem, you need to look for high ESR capacitors in the vertical deflection circuit and power supplies. If you are not sure how to do this, you are probably better off having the unit repaired by an experienced technician. Most repairs if the set is mostly working and you can take it in on a set like this come in well under $250 total. David PiNhEaD wrote in message ... I have a Toshiba model TP5580A projection TV that was given to me by a friend. This is a older unit manufactured in 1992. I was told the picture was blurry so I cleaned the lenses and the mirror before plugging it in and the picture is nice and bright and crisp believe it or not. But when I turn it on there is a horizontal line in the center of the TV. It looks like the picture is getting sucked into the line. After it warms up for about 5 minutes the line moves upward about 12 inches above center and becomes very faint. At this point nothing is being sucked into it anymore and it is just a couple of small faint lines. You can only see the lines when the TV has a light picture on it. Anyway most people don't even see the lines at this point but it is driving me crazy. I have never worked on a projection TV before but I do repair arcade monitors on a regular basis. Based on my experience with arcade monitors I would think the problem lies with the horizontal output transistor either starting to go bad or a cold solder joint. But I do not have any schematics or service manual to work from. Unlike an arcade monitor which has one circuit board this has several pcb's as well as 3 crt's. Can anyone point me in the right direction or better yet tell me where I can obtain a service manual and schematics, preferably in adobe acrobat format. I have been searching google for the last 2 days in my free time looking for anything related to this issue and found nothing. I did see many posts about fluid leaking out onto the boards causing a variety of problems but nothing like this. Thanks, in advance Pat |
#3
|
|||
|
|||
Toshiba Projection TV Help.
"David" wrote in message ...
If the service manual is still available, you need to buy it from any Toshiba authorized parts dealer. Toshiba has a pretty strict policy of only selling service information to servicers for what they call legal liability issues. As to your problem, you need to look for high ESR capacitors in the vertical deflection circuit and power supplies. If you are not sure how to do this, you are probably better off having the unit repaired by an experienced technician. Most repairs if the set is mostly working and you can take it in on a set like this come in well under $250 total. David PiNhEaD wrote in message Well there is no way im taking it in for repair, what fun would that be. If I were that lazy I would just go buy a new one money is not the issue. I am more than capable of testing and replacing capacitors, every monitor I rebuild gets a complete cap kit. Since I know the problem dissipates when the set is warm I will start tonight with a can of freeze spray to try and isolate the component. I still want to get my hands on a service manual, I can find the bad component and replace it if I poke around enough but lets face it life is much easier with a manual and a set of schematics. Sure would be nice to check my voltages and make sure they are O.K. As always any help is appreciated. Still looking for a service manual. Thanks, Pat |
#4
|
|||
|
|||
Toshiba Projection TV Help.
You dont need a service manual to ESR caps ...
kip -- As always any help is appreciated. Still looking for a service manual. Thanks, Pat |
#5
|
|||
|
|||
Toshiba Projection TV Help.
You should have no problem identifying the vertical output circuit as it
likely will be an IC or a couple of transistors on heatsink nearly directly connected to one side of the deflection yokes. Then there is the jungle ic which does most of the signal processing and sync processing, 64 pin or so ic. Toshiba may still have been labeling the boards in 92 with the general locations of the circuits. The service manual will be a tough one to find. In 92 Toshiba had relatively few authorized servicer which would have had the manual. Since then many independent servicers have simply gone out of business. You might get lucky and find a local servicer that is willing to sell you the old copy (if they have one) as odds are very low they will ever see that model again due to the extreme old age. David heypat1 wrote in message om... "David" wrote in message ... If the service manual is still available, you need to buy it from any Toshiba authorized parts dealer. Toshiba has a pretty strict policy of only selling service information to servicers for what they call legal liability issues. As to your problem, you need to look for high ESR capacitors in the vertical deflection circuit and power supplies. If you are not sure how to do this, you are probably better off having the unit repaired by an experienced technician. Most repairs if the set is mostly working and you can take it in on a set like this come in well under $250 total. David PiNhEaD wrote in message Well there is no way im taking it in for repair, what fun would that be. If I were that lazy I would just go buy a new one money is not the issue. I am more than capable of testing and replacing capacitors, every monitor I rebuild gets a complete cap kit. Since I know the problem dissipates when the set is warm I will start tonight with a can of freeze spray to try and isolate the component. I still want to get my hands on a service manual, I can find the bad component and replace it if I poke around enough but lets face it life is much easier with a manual and a set of schematics. Sure would be nice to check my voltages and make sure they are O.K. As always any help is appreciated. Still looking for a service manual. Thanks, Pat |
#6
|
|||
|
|||
Toshiba Projection TV Help.
Very little time to look at it tonight, had to work late and open house
(meet the teachers) at my sons school. I did have about 45 minutes when I got home from work earlier. I followed the wires back from the yoke to the board knowing this would get me in the general area then I looked for the transistor on the heat sink and started spraying components one at a time with the freeze spray. Knowing the problem went away when the set heated up I let it warm up first until the problem was almost gone. Then when I hit cap # 332 and 315 with the freeze spray the problem comes back right away and 10 x worse. Just to confirm I heated it back up with my heat gun and the problem went right away. These 2 caps are right next to each other and it was hard to spray one cap with the freeze spray and not the other, same goes for the heat gun. I do not have a esr meter so this was a quick way for me to find the bad component while the board was still in the TV. I pulled the board and wrote down the capacitor values so I can pick them up tomorrow. Figures I have hundreds of caps around that I use all the time on arcade monitors but I did not have a 160V 220 mf anywhere. I hope to have time tomorrow to pull my out my scope and function generator so I can check the esr on the rest of the caps. Only makes sense to check all of them and replace any bad ones while the board is out. It would still be nice to run across a service manual. There is so much more to these then arcade monitors I wanted to get the service manual so I could take a good look at the circuits and any material related to the lenses and the fluid in the lenses etc. Always looking to learn more Thanks for the help and I will keep you posted. Pat "David" wrote in message ... You should have no problem identifying the vertical output circuit as it likely will be an IC or a couple of transistors on heatsink nearly directly connected to one side of the deflection yokes. Then there is the jungle ic which does most of the signal processing and sync processing, 64 pin or so ic. Toshiba may still have been labeling the boards in 92 with the general locations of the circuits. The service manual will be a tough one to find. In 92 Toshiba had relatively few authorized servicer which would have had the manual. Since then many independent servicers have simply gone out of business. You might get lucky and find a local servicer that is willing to sell you the old copy (if they have one) as odds are very low they will ever see that model again due to the extreme old age. David heypat1 wrote in message om... "David" wrote in message ... If the service manual is still available, you need to buy it from any Toshiba authorized parts dealer. Toshiba has a pretty strict policy of only selling service information to servicers for what they call legal liability issues. As to your problem, you need to look for high ESR capacitors in the vertical deflection circuit and power supplies. If you are not sure how to do this, you are probably better off having the unit repaired by an experienced technician. Most repairs if the set is mostly working and you can take it in on a set like this come in well under $250 total. David PiNhEaD wrote in message Well there is no way im taking it in for repair, what fun would that be. If I were that lazy I would just go buy a new one money is not the issue. I am more than capable of testing and replacing capacitors, every monitor I rebuild gets a complete cap kit. Since I know the problem dissipates when the set is warm I will start tonight with a can of freeze spray to try and isolate the component. I still want to get my hands on a service manual, I can find the bad component and replace it if I poke around enough but lets face it life is much easier with a manual and a set of schematics. Sure would be nice to check my voltages and make sure they are O.K. As always any help is appreciated. Still looking for a service manual. Thanks, Pat |
#7
|
|||
|
|||
Toshiba Projection TV Help.
Replaced the 2 caps I hit with the freeze spray and found 2 more that needed
to be replaced. Fired it up and it works great, picture is even better then before. It has been running for about 3 hours now with no issues. Thanks for the help Pat "PiNhEaD" wrote in message ... Very little time to look at it tonight, had to work late and open house (meet the teachers) at my sons school. I did have about 45 minutes when I got home from work earlier. I followed the wires back from the yoke to the board knowing this would get me in the general area then I looked for the transistor on the heat sink and started spraying components one at a time with the freeze spray. Knowing the problem went away when the set heated up I let it warm up first until the problem was almost gone. Then when I hit cap # 332 and 315 with the freeze spray the problem comes back right away and 10 x worse. Just to confirm I heated it back up with my heat gun and the problem went right away. These 2 caps are right next to each other and it was hard to spray one cap with the freeze spray and not the other, same goes for the heat gun. I do not have a esr meter so this was a quick way for me to find the bad component while the board was still in the TV. I pulled the board and wrote down the capacitor values so I can pick them up tomorrow. Figures I have hundreds of caps around that I use all the time on arcade monitors but I did not have a 160V 220 mf anywhere. I hope to have time tomorrow to pull my out my scope and function generator so I can check the esr on the rest of the caps. Only makes sense to check all of them and replace any bad ones while the board is out. It would still be nice to run across a service manual. There is so much more to these then arcade monitors I wanted to get the service manual so I could take a good look at the circuits and any material related to the lenses an d the fluid in the lenses etc. Always looking to learn more Thanks for the help and I will keep you posted. Pat "David" wrote in message ... You should have no problem identifying the vertical output circuit as it likely will be an IC or a couple of transistors on heatsink nearly directly connected to one side of the deflection yokes. Then there is the jungle ic which does most of the signal processing and sync processing, 64 pin or so ic. Toshiba may still have been labeling the boards in 92 with the general locations of the circuits. The service manual will be a tough one to find. In 92 Toshiba had relatively few authorized servicer which would have had the manual. Since then many independent servicers have simply gone out of business. You might get lucky and find a local servicer that is willing to sell you the old copy (if they have one) as odds are very low they will ever see that model again due to the extreme old age. David heypat1 wrote in message om... "David" wrote in message ... If the service manual is still available, you need to buy it from any Toshiba authorized parts dealer. Toshiba has a pretty strict policy of only selling service information to servicers for what they call legal liability issues. As to your problem, you need to look for high ESR capacitors in the vertical deflection circuit and power supplies. If you are not sure how to do this, you are probably better off having the unit repaired by an experienced technician. Most repairs if the set is mostly working and you can take it in on a set like this come in well under $250 total. David PiNhEaD wrote in message Well there is no way im taking it in for repair, what fun would that be. If I were that lazy I would just go buy a new one money is not the issue. I am more than capable of testing and replacing capacitors, every monitor I rebuild gets a complete cap kit. Since I know the problem dissipates when the set is warm I will start tonight with a can of freeze spray to try and isolate the component. I still want to get my hands on a service manual, I can find the bad component and replace it if I poke around enough but lets face it life is much easier with a manual and a set of schematics. Sure would be nice to check my voltages and make sure they are O.K. As always any help is appreciated. Still looking for a service manual. Thanks, Pat |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Non-huge parliament or projection hinge: exists? | UK diy | |||
Toshiba Rear Projection TV convergence and power problem | Electronics Repair | |||
Toshiba 43" Projection 43H72 - Colors Separated | Electronics Repair |