tscheucher
User
Apr 24, 2010, 9:27 PM
Post #4 of 5
(2027 views)
Shortcut
|
|
Re: [1986VeeDub] Toshiba TP61F80 PLEASE HELP
[In reply to]
|
Can't Post
|
|
Hello again!
Don't be lost - That's only a tv show on ABC'S network :-)
It's a hard task to teach a newbee how to fix rear projection tv's, but I'll try to explain as good as possible. What I wanted to tell you was first to check bad solder joints. That's a common fault occurring after a few years of use. Have a visible check on all the boards before you replace any parts - That can save a lot of money because some components gave up work just because of bad circuit connection.
The next thing I wrote you was to check the video amplifier ic and the convergence output ic for short circuit or non-operation. Most of the rp-tv's stop working and start blinking when one or two of those ic's are faulty. You have a tv where those 2 ic's are soldered on the main power supply board on big heat sinks. The ic's look like the one on the foto: http://files.tradoria.de/...116030231_135225.jpg
In general they came with a production fault and die after a 3 or 4 years of use (sometimes 6). The manufacturer of those ic's made an "update" of their internal circuit to achieve a longer lifespan. They are sold now as STK392-150 (=type number).
I assume that you know what a part or position number is. It's the white (sometimes black) overprint on the circuit board which represent's the part number. The convergence ic's have the number Q751 and the one next to it. Just look at the markings on the circuit board and you'll find them. Do the same procedure for locating all other resistors, transistors, capacitors a.s.o..
If you can exlude faulty convergence stages, you have to look for other reasons that might be these ones:
- Defective transistors QA01 and QA02 (that's their number on circuit board) They could have short circuit between 2 or more pins.
- Defective transistor Q641 and defective zener diode D875
- Defective R327 (3,3 Ohm = value)
R 327 is a safety resistor, which burns or get's open circuit when ic LA733 is dead. The LA733 is an ic responsible for vertical deflection.
That's all I can tell you about tv repair on a rpTv like your's 'cause I haven't seen it and it's not possible to introduce somebody in tv repair without any (or too little) background knowledge on that topic.
In case of doubts, please ask your local repair shop for further help because as experienced the are much apprechiated when people only buy spare parts for rptv's - They don't really like to repair them unless they have to :-)
best regards
(This post was edited by tscheucher on Apr 24, 2010, 9:31 PM)
|
FORUM
SEARCH
WHO'S 
LOG 
RULES
It blinks about every sec for as long as i have the TV plugged in. I have tried plugging it into every other outlet in the room and it just blinks at me! I took the back off to look at the inside and nothing seems to be burnt there is not smell of something burning. I don't want to junk this TV since it has worked perfectly since i have owned it. I am a NEWBIE when it comes to internals of a tv. Any help would be GREATLY appreciated. Thanks in advance! 
