Hello,
We got 6 toshiba 32A14 tvs and the other morning 3 of them wont turn on, just get a chirping sound. (1 was on a good quality surge protector bar).
I replaced the 2 transistors in the horizontal hold output, Q402 and Q405 and it still chirps.
Im hoping its not the flyback. Any ideas what it could be would be appreciated.
Thanks.
First off, why was the transistors replaced? Were they bad, and how? Do you have a service manual as well as a schematic? A chirping noise comming from the power supply will usually indicate that there is a short in the set and thats the SMPS shutting on and off. There most likly is a shorted horizontal output transistor, if thats not shorted, check the regulator IC as well as the mosfet that regulates the power supply. If you have the schematic, send me a copy at [email protected] if you wish to have further assistance.
Ok I looked things over. Q405 if it is shorted, it should be replaced with the original, if its not shorted though, put back in the original. If you need the transistor, 2SD2638, it is available at http://www.partstore.com/ModelDetail.... and enter 2SD2638 in the part box. You should also check T401 for bad connections, check Q402,D408,D409,D405,R410, and all of the burnt or scorched looking parts in the sweep section. Also look for poor or dull looking connection around the flyback. Now in the power supply, take out Q 502, and Q514 and check them for shorts. Look for slightly bulging capacitors in both circuits. Get back to me if you have any questions or find something or something your not sure of.
Thanks for your valuable help.
I will try as you suggested and let you know.
Hello,
I checked everything except T401.
Any idea how to test this part?
Thanks for your help.
Its not bad, just see if there are any ring cracks on the connections. So the horizontal output transistor is not shorted?