Sony kdl-40v2000

[Alastair E]

Ive a Sony 40" LCD that has a very intermittent power off/re-boot fault.

Happens particularly if you change channels,--but not often-- the picture will freeze for a second or two, then the set will go off, re-boot and function as normal. green power ind light stays on all the time.

Ive heard of this before with these Sony sets, and apparently its something to do with some diode or other in the PSU.

Tried the search feature--but as always its pretty useless!

Any ideas....?

[Dang]

Re: Sony kdl-40v2000

Try searching specifically for your power supply, not only on here but Google too, I did this for a screen fault using the T-con board number and strangely it brought me right back here for the answer I was seeking.

[Alastair E]

Re: Sony kdl-40v2000

Oddly enough I tried this but got little info on the problem, only loads of ads for replacement supplies.....

[tom66]

Re: Sony kdl-40v2000

If you check the service menu (cryptic) then it may list the power off cause.

In standby press i+, 5, VOL+, power then I think it's on page 97,98 or 99 (just type in page number, should jump to it)

[Alastair E]

Re: Sony kdl-40v2000

Is there another way to enter that service menu? My universal remote that works all the sets functions--doesnt have an i+ button.....

[Glitcher]

Re: Sony kdl-40v2000

Have you tried a factory reset?

[tom66]

Re: Sony kdl-40v2000

i+ = info button if available.

[Alastair E]

Re: Sony kdl-40v2000

Have you tried a factory reset?

Yup--just done a reset, will run the set for longer later, see if it faults, so far its been OK but only run for 15 mins or so...

More I think about it, I think I'm confusing this fault with another where these Sonys go to standby and that is summit to do with this diode on PSU for the 13v supply--Just wish I could find that info to confirm!

HATE Sony sets, for 40 years, Ive Never had much luck with 'em More trouble than they are worth!

[tom66]

Re: Sony kdl-40v2000

I've always had a fond spot for Sony but I've never really liked the diagnosis/troubleshooting systems they have built in. That and they are generally pretty poor spec for the price.

[Alastair E]

Re: Sony kdl-40v2000

Ha!--I remember the Sony KV1810 sets--Now Those were summit Else!

A series Buck-Boost style PSU with no isolation and a GTO main switching device (A sorta Gate Turn Off Thyristor) Those devices cost Then (80's) about £20 apiece--only available from Sony, one in line-stages and one in the PSU. SG-6533 rings a bell as part type. Small footprint 'TO-3' package, like another ancient transistor AD142....

If for ANY reason, Line drive should stop/not start soon enough, the line stage GTO would short, then short the one in the PSU, applying full rectified mains to the chassis that would disintegrate the mains fuse and often damage the mains-switch contacts.

The unsuspecting engineer would replace the pair along with the mains-fuse and Bang--they would fail instantly again.

£40 was a LOT of dosh back then to go poof in a microsecond!

Usual cause was practically every cap in the PSU and line drive/regulator stages along with the third-harmonic tuning cap, A Huge (for its capacitance) weird knobly blue thing....

I used to get around fitting these mega-bux devices by altering the line-drive stage and use a standard horizontal O/P Transistor, The same could be done for the PSU too, but using a beefier transistor for that one, and replacing the drive transformer for both parts with ones suitable for driving Transistors.

Think Thats where my mis-trust of this make began......

As you say--Overpriced for what you get. I cant recall Ever buying a new 'Sony' anything.....

[Alastair E]

Re: Sony kdl-40v2000

Nah--The fault with this soddin' sony is still there.....

It'll be fine--Providing you Don't change channels.......

Sometimes when changing channels just after the picture appears, it will freeze frame, sound mute, then black out the screen, PSU relay click-then click again and re-boot to the previous channel you were watching!

I dunno--weird one.......

[Alastair E]

Re: Sony kdl-40v2000

Hmm.....

A search around the web including the Sony community forums indicates this is a fairly common fault with a few Sony models....

However, I cannot find anyone who has any clue on whats causing it or any successful outcomes!

Typical bloody sony!

[Dang]

Re: Sony kdl-40v2000

Oddly enough I tried this but got little info on the problem, only loads of ads for replacement supplies.....

The only other thing I can think of is the Freeview module, I know the Sony A2000 RPTV would turn off and restart on occasion when using the Freeview tuner, the old Sagem RPTVs would do the same too especially as more Freeview channels were added, so try using a stand alone Freeview box and see if it does the same, I have a Sky box attached to my A2000 and have had no "turning off" issues since, I hope this helps.

[Alastair E]

Re: Sony kdl-40v2000

Yes--Pretty sure its summit to do with Freeview--Probably in the firmware somewhere there's an issue.

What surprises me is that this fault Isnt confined to this model, some much later sets seem affected, yet there doesn't appear any resolution for those either!

There's no firmware updates available for this model from sony-europe/uk, although sony US seems to have F/W available...