You need to obtain service manual, at the link below... as they are in many and various places...
http://www.scribd.com/doc/20636302/Toshiba-42hp66-Service-Manual
Hi, well I applaud you for wanting to have a go and try to repair you set. But PLEASE, start in the right place, otherwise you will simply waste your time and money, You see, you MUST start, in the right place, The power supply, FIRST, as, if, that isn't right, nothing else can be. But you simply cannot do anything without a Service Manual. In this it has everything one needs to repair the set. OK if it is shutting down, after that amount of time, of working and then faulting, then it is most definitely a "Thermal" problem, the way we "Find" problems such as this is "Freeze Spray" you use this on each component that is suspected of being the "Culprit" and you will soon,find that errant component. Now, also not every fault is a Capacitor, I see many, many people that think, that Capacitors are always the "Culprit" and replace them, because someone else had done so and it worked, well that maybe sometimes true, but most Symptoms, can, and do have many, many different "Causes" & also, now while that may be true in a few cases, a faulty Electrolytic Cap, or even, ordinary, Cap goes faulty, this is only a SYMPTOM, something has damaged those caps causing them to "Fail". One MUST always find the root "Cause", otherwise if you just treat, the SYMPTOM, the "Cause" will just make the "Symptom" come back, in short order, as the prime cause still, hasn't been fixed., Now Capacitors hate AC ripple, or Over Voltage. Thats it. Oh.. and Heat, if these Capacitors, are too close to a Heat Source, then thats a prime cause of failure. Resistors, hardly ever go faulty,and if they do, it is generally obvious. However it doesn't hurt to check values with our Multimeter. Remember though resistors are made, with up to 20% tolerance from stated value, as such, are not too critical, unless in Timing circuits etc. Always check, the Values, of resistors, as with any other component, with the power OFF. Now Diodes especially "Zener Diode", are another thing to check, those and ordinary "Signal Diode" should always be suspect. next we have Transistors and IC's. The Transistors MUST ALL be checked to see if they have a good, "Junction" this is done, with our meter set to "Diode Test" and usually are about 0.6 to 0.7. With IC's you must check, voltage levels, or Logic Levels, going in and out, have a look at the circuit diagram, and it will tell you what they should be. It is a good idea to always measure the Power Supply voltages, see if a "Rail" is Low, that will be because some component has gone somewhat or all short circuit, to Earth, now, if the "Rail" is Higher, suspect an "Open Circuit" component, like a Diode, or Transistor. The voltages expressed in the manual are spot on, ANY variation MUST be investigated. I have been doing all this for over 30 years now, and I do indeed wish, we could have a set of "Symptoms" and be ables to say.. "Oh that;s the so-in-so and replace this" however unfortunately this although does happen, most "Symptoms" can have literally tens, of "Causes" all often "Interlinked" One simply has to do a methodical troubleshooting procedure, and always think, "are my Voltages Correct" as this is how, you Fix the problem, by making them so. Keep up the good work. If that link above doesn't furnish a Service manual, it is imperative you get one, even if you must pay for it. It will pay for itself in about 2 mins.
Hi, sorry to hear you have a problem, but you see, just changing the capacitors well seldom permanently "Fix" anything for very long. You see, those "Blown Capacitors" were a "SYMPTOM" and are a "RESULT" of some other problem, seldom these days for capacitors fault, Unless, they are overheated. To spontaneously fail. The thing that "Kills" Capacitors, is AC Ripple/Voltage, and Over-voltage. So you see you MUST first find why those conditions exist before you can even begin to replace anything Capacitors included. So as ALWAYS the first place we start is at the Power Supply, now you make sure those voltages are correct. and if they aren't find out what not, and what is causing the problem. Then, in that way you can isolate the fault and fix the cause at the same time. That way it is "Fixed" and not symptomatically treated. Also it is nearly impossible to do anything without a service manual, you MUST try to get one of those, they will also help you identify exactly what is wrong and where to look and what to do.
