no tv channel

guys,

i need help on my tv, its a sony 20 in. flat model SONY KV-20FV12 , problem is, it has no tv channel, anywhere i put the channel it leaves a blank screen saying N0 TV SIGNAL even if i hook up antenna or cable ,but AV input is working fine, i can use it on my dvd or vcr, but on regular tv it says no signal

i havent repaired a tv yet, but kowledgeable in electronics, is it worth it?

thanks

Reply to
zackde
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No, not for you to try repairing it. Could be a bad tuner but how could that help you if you have no experience?

Reply to
Charles Schuler

On Sun, 24 Apr 2005 13:58:22 -0700, zackde wrote (in article ):

Probably not. Just use antenna connected to VCR and plug VCR into AV inputs.

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Reply to
DaveC

Most common on these sets is a bad tuner. Tuner replacements are pretty routine. No reason not to try it if you are familiar with electronics. Soldering in the tuner itself is probably not worth trying if you don't have good equipment and good soldering skills, but changing the tuner or repairing its supply should not be a stretch.

Verify that there is 30+ volts going to the tuner. If not you are missing the tuner supply. Check that you have 5 volts on several pins. You could be missing a 5 volt supply. There are some surface mount transistors in the vicinity of the tuner that can bring it down if shorted.

Tap on the tuner and see if you get signal. Same on the surrounding circuit board. If this affects it you may have some bad solder connections. Could be a bad solder joint in the tuner, maybe a bad tuner. Sure way to check is to bypass the tuner with an IF signal, but if you don't repair TVs you won't have an IF signal generator. If you want to take a shot at replacing the tuner you can get a rebuilt tuner from Tip Top TV & VCR in Reseda, CA for $27 after exchange.

Leonard

Reply to
Leonard Caillouet

This can be in the video select circuit area, or in the tuner module, or the IF module. This is not something a home do-it-yourselfer can service. You will have to take the set to a service centre, and have it properly troubleshooted, and serviced. Considering the age of the set, ask for an estimate.

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JANA
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Reply to
JANA

Why would one ask for an estimate based on the age of the set? Why not get an estimate regardless?

Since the IF module is integrated into the tuner, there is not much reason a person with reasonable electronics knowledge and decent soldering skills could not attempt this repair. If the set gets no signal when switched to the tuner, and the audio/video switches over ok, it is unlikely that the problem is in the video select circuit. If the supply voltages are at the tuner, it would be reasonable to replace it.

Sure, as I stated in another post, having the right equipment and knowledge would allow a more certain diagnosis, but many techs would not even bother to inject IF and would just change the tuner.

A DIYer could take a $32 gamble, replace the tuner,and if it does not fix it not have lost as much as an estimate charge. He could then maybe even trade the tuner for a real estimate. I'd likely take that deal.

Leonard

the

Reply to
Leonard Caillouet

It has been a number of years since I worked on the FV series of Sony. I used to work in Sony warranty service.

On the Sony 20FV12, if I remember correctly, the IF and tuner are separate modules. They are also very critical to work on. As for the cost of these modules, they are a lot more expensive than $32 !!!

In his case, the fault can be a number of other things. But, these modules can not be ruled out.

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Reply to
JANA

Either your recollection is wrong or you are going out of your way to discourage a DIY repair. I assume that you are not one of those obnoxious techs that we tire of hearing the "take it to a real repair shop" refrain from, so you might want to make sure you know your facts before you offer advice. It is one thing to give lousy advice because you don't recall correctly, but you might want to check things out before you try to correct someone who knows what he is talking about.

I currently run a shop that is a Sony ASC. The KV-20FV12 can't be more than about 3 years old. It has an integrated tuner and IF stage. In fact, the FV series has never had a discrete IF block. Also, even on the older sets with the very common problems in the IF block, it is a simple matter to resolder the connections. It requires only average soldering skills and is a very routine repair. Soldering connections in a tuner, of course, can be a little more tricky.

It is also very easy to check the source that I recommended, Tip Top TV & VCR and find that, indeed, a rebuilt tuner can be had for $27, including shipping, with return of the dud, costing $5 or less in shipping. Hundreds of techs use their tuners and have found their work to be very reliable. Frankly, I trust them more than a factory new tuner on some of the ones that are known to have problems with bad solder connections. In fact, other than one DOA, I can not recall ever replacing one of their rebuilt tuners after installing it and have used dozens of them over the past several years.

Leonard

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Reply to
Leonard Caillouet

i have a decent experience in electronics (i used to be an IBM technician)but frankly no experience on TV, now that you guys pinpoints several possibilities i might try it out, or if all fails, ill just hook-up the tv to a VCR w/ tuner (very genius suggestion haha)

if ill replace the tuner how much will it be roughly? & where can i get it? im in NJ

thank u all

Reply to
zackde

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