APEX PF2720 MAKES WEIRD NOISE

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Can anyone help or offer some direction?

My Apex TV was working fine until today.

When I turn it on there is a strange whining sound and no picture. Anyone had an experience with this?

Thanks,

Gary

Re: APEX PF2720 MAKES WEIRD NOISE
On Thu, 15 Jun 2017 18:20:41 -0700 (PDT), snipped-for-privacy@gmail.com
wrote:

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That's what they all say when something blows up.  The next step is to
blame someone or something.

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Yes.  My guess(tm) is a switching power supply with leaking and
bulging electrolytic capacitors.  The capacitor sometimes makes some
hissing or screaming noises when it boils off electrolyte.  The noise
may also be coming from the speakers as a blown capacitor might cause
the power supply to oscillate.  The noise is usually followed by dead
silence after the fuse blows.

The Apex PF 2720 is 27" CRT (picture tube) TV first sold in 2003. That
makes it around 14 years old:
<https://www.amazon.com/Apex-PF2720-27-Flat-Screen-Stereo/dp/B0000CAPT1>
It's highly likely that something that old has parts that have not
aged very gracefully.  Open it up and look around.  You'll probably
see something like these:
<https://www.google.com/search?q=bulging+capacitors&tbm=isch
Usually, some kind of maker and model specific capacitor recap or
rebuild kit is available on eBay.  However, I couldn't find anything
for this model TV.  The labor charge for fixing such an old TV might
be high enough that a replacement LCD TV might be more economical.

eWaste methinks...

--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
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Re: APEX PF2720 MAKES WEIRD NOISE
snipped-for-privacy@gmail.com wrote:

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** So there is normal sound from the speakers ?  

If so, the set many just need a good clean around the picture tube and any wiring going to and from same.  

I have used rags moistened with denatured alcohol to get all the black soot and dust off, plus a vacuum cleaner if it is really bad.  

It's probably an outside chance, but what have you got to lose ?

FYI:  

UNPLUG THE SET AND LEAVE IT FOR 10 MINUTES BEFORE DOING ANY CLEANING.  


.....  Phil  

Re: APEX PF2720 MAKES WEIRD NOISE
On Friday, June 16, 2017 at 4:28:08 AM UTC-4, Phil Allison wrote:
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ne had an experience with this?
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y wiring going to and from same.  


Cleaning in and around the second anode assy won't help a no picture condit
ion and whine, which is what OP complained about.


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Good advice, assuming his TV's HV transformer has an internal bleeder.  If  
it doesn't contain an internal bleeder, the CRT may store 20KV for several  
days at the very least and will deliver nice jolt to whoever tries to wipe  
down around the second anode cup, even days later.  Some TVs mute the video
 first before the HV is shut down, and the charge on the CRT remains very h
igh with no bleeder.  

It would have been nice if OP had told us if it's a CRT, plasma, or LCD.  T
he only thing they all have in common is that produce a picture.


Re: APEX PF2720 MAKES WEIRD NOISE
On Thu, 15 Jun 2017 18:20:41 -0700 (PDT), snipped-for-privacy@gmail.com
wrote:

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Another guess is a shorted horizontal output transistor and the whine
is a switched power supply trying to drive a dead short.  In any case
not worth fixing.

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Re: APEX PF2720 MAKES WEIRD NOISE
On Thursday, June 15, 2017 at 9:20:46 PM UTC-4, snipped-for-privacy@gmail.com wrote:

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Is the sun shining where you are?  Knowing the weather is as about as helpful as the information that you posted.

Start with model number.  Absent that, whats the technology?  CRT, Plasma, or LCD/LED?

Whining complaints along with a change of performance are *usually* a switch mode supply under a higher than designed for load.  

Re: APEX PF2720 MAKES WEIRD NOISE
On Friday, June 16, 2017 at 9:57:32 AM UTC-4, John-Del wrote:
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Oops, see the model in the title..

If you have a DMM, check the LOP/Horizontal output transistor for a Collector to Emitter short.  That's the easiest check to make.  

Other than that, any kind of shorted device on the secondary of the smps will cause a whine from the supply.  

Re: APEX PF2720 MAKES WEIRD NOISE
On Thursday, June 15, 2017 at 9:20:46 PM UTC-4, snipped-for-privacy@gmail.com wrote:
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Thanks to everyone for taking the time to respond. Jeff, The images from the link you supplied were awesome. I think it's time for me to help the economy and buy a new TV.  

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