After turning on, my tv (21 inch CRT) produces peculiar rattling noise like high voltage sparking. The screen remains blank and there is no audio.

First, You should to replace by original part, then you should check the voltages on power supply, and check the voltage for vertical IC based on datasheet, also check the voltages on vertical section including yoke and last you should check the ESR capacitors on vertical section.

Hi, It's time to get a new one. Is this a TV or a computer monitor.?

The power supply regulator section is faulty. Check this site "electro-help' google for it. it have all details about how to troubleshoot this problem. i can't copy and paste the content of this post. It is copy protected.

Hello jreese, Hi, Most definitely its a horizontal output problem, your tv has no horizontal deflection to pull the screen vertically, the power transistor that produces the high voltage is bad, this needs to be replaced. definitely you always have sound, the audio section is a separate block from the high voltage block, go look for a technician to have this checked.

The set has a high voltage problem, "the flyack transformer is defective" It generates the high voltage in the picture tube and with the help of the video circuits it produces a picture. It is not cost effective to repair the tv, cheaper to replace.

If the noise is louder appears as if sparking inside the set than turn off set as there may be leakage in the EHT (extra high tension transformer) which can be replaced by some technical expert,if the noise is not louder than there is failure of internal power supply,get it repaired by technical expert.

Easy repair with some Super glue.Must take the tv back cover out.The FBT-the big block of plastic with a red wire with a cap hook to a CRT(tv tube).It have a high voltage gap going through a "3 inches paper clip steel bar on a FBT the big black plastic block.Put some super glue on that "3 inches paper clip steel bar on that big black plastic block.Should stop the high voltages gaps through that "3 inches paper clip steel bar causing a high pitched noises.

the power supply filter condensor got leaky in ur tv,,,,,
well it will cost 80 rs... the picture will wave ,, call a tech person to change it. value of condensor 150mfd 450v

Warning: Flyback Transformer Failure. ( extreme high voltage ) 22,000 Volts +

Do not attempt to fix this without another human being present who's trained in CPR.

Thank you for choosing FixYa!
Azkeyz, Wizard Division.

You have no high voltage, like many in this forum, this model of Philips has some of the same problems. Look around here you may find the answer to your set. If not check Vertical IC, TDA8177, audio ic on signal board up front on left. check Power supply first for blown fuse, 1000, 2004, 1300, 1900 etc. No sound or pic means something is open. Does set has L E D lights on front of set?