Help needed re RF sound in RGB mod Sony KV-F29SF1

[captaineos]

Hi everyone
Long time CRT enthusiast and here needing help with RF SOUND post RGB mod.
Sony KV-F29SF1
Australian Model
G3F Chassis
Sony CXA1587S RGB chipset
Work performed:
- Wire up female SCART head with R G B terminated with 75-ohm resistors to ground
- SCART Sync pin to Male RCA jack to plug into Video 1 IN for sync
- SCART sound pins to male RCA jacks for sound on Video 1
- Voltage divider of +5V via 1.5K ohm resistor and 470ohm resistor to ground to make 1.1volts, measured in circuit perfect and switched
- Blanking of 1.1v to pin 44
- R G B to pins 47,46,45 respectively
- Lifted factor 100ohm chip resistors

Turned on, image fantastic, stable, centered, vibrant, joy.

However
When you press the TV/VIDEO button it goes from RF to Video 1,2 and 3.
The sound isn't turned off from RF!
So you get the untuned channel static "chhhhhhhhhhhhhh" noise mixed in with the stereo input.
If you select the RF input; e.g channel 1 then the sound is muted and no untuned static is heard.
If you select Video 1, again RGB image is there looking perfect but you get the static sound and no volume control. E.g volume up or down doesn't lower the static.

Huh?

Any ideas would be great as the only option I see is to ask my friend to run external speakers which isn't ideal.
Jeremy from Canberra, Australia.

[KPackratt2k]

Do you have any RF devices you can test with (e.g. a VCR or an old game console with an RF adapter) to see if having a device connected to RF would get rid of the problem? It sounds like the microcontroller or audio switching chip on the TV could be having issues with its sound detection circuit. If you're certain that you'll never use RF on this TV, you can lift the pins responsible for pulling sound for RF from the jungle chip or audio switching chip, depending on which chip has pins for the RF audio.

Also, check to make sure the ground for your RGB connector is going to a ground pin. It's possible that you've soldered the ground of your connector to an active pin for RF audio. Check for continuity with a multimeter from the shield of the AV jacks to determine if it's ground or not.

[bonicb]

Hi captaineos, did you get this issue sorted? I am about to rgb mod my KV-F29SZ2 Australia model, which shares the same service manual as your tv. It seems to be nearly identical in fact.

im unable to find any information on adding rgb to the CXA1587S. I would appreciate any more info you could share regarding how you wired scart to this tv.
Cheers from tassie.

[captaineos]

Hi bionic
For the RGB video, I think you have all the information you need, the next step is the 'doing'.
For the post problem of turning on blanking for RGB but white RF static untuned channel sound coming through, no I did not solve it. The customer simply uses a stereo system for sound and not the TV speakers.

[roboblaster]

Hey guys. Very interested to hear if you find a solution to this...

I'm currently researching how to mod a KV-L34SN11. It uses the same jungle chip (CXA1587S) and chassis (G3F).

This might be info you already know but there's some info on Sunthar's page on G3F:
https://sector.sunthar.com/guides/crt-r ... ce-manuals

Also I found this page on flickr showing a successful G3F mod:
https://www.flickr.com/photos/159678005@N08/43835891420

It doesn't answer the question directly but might give some clues, since they don't mention issues with rf audio there.

[vol.2]

Hey guys. Very interested to hear if you find a solution to this...

I don't think the problem was ever confirmed to effect all sets; it might have just been a stray solder blob shorting the RF audio pin or something.

If it does effect all similar sets, then KPackratt2k's suggestion to lift the RF pin was probably a good first try, so long as RF wouldn't be used. And it could obviously be put on a switch if you wanted

I've never seen this particular problem come up before on the forums though, so I am not convinced this wasn't a repair goof, or a fault with the particular set.

[PapaBergsy]

Hey guys. Very interested to hear if you find a solution to this...

I'm currently researching how to mod a KV-L34SN11. It uses the same jungle chip (CXA1587S) and chassis (G3F).

This might be info you already know but there's some info on Sunthar's page on G3F:
https://sector.sunthar.com/guides/crt-r ... ce-manuals

Also I found this page on flickr showing a successful G3F mod:
https://www.flickr.com/photos/159678005@N08/43835891420

It doesn't answer the question directly but might give some clues, since they don't mention issues with rf audio there.

Hey Roboblaster,
I have this exact same model - Svideo looks good but was also thinking of doing the RGB (Scart) Mod following the same guides you have mentioned above and was also curious about the sound issue. Let us know how you get on with the mod - Turning this beast of a unit over on carpet or heavily cushioned surface to work on is going to be fun to say the least! I'm hoping to get the mod done without having to unplug everything / taking the chassis out.

Here is the Schematic for a very similar model (same series) G3F Chassis which may be helpful to you with the mod. Shows the unpopulated Teletext connector with RGB lines etc to tap into. 5V Regulator is also close by.
https://elektrotanya.com/sony_kv-f25mf1 ... nload.html

[roboblaster]

Thanks guys
My set wasn't turning on, so I took it to a local repairer to fix first. I want it to be in a good state to start before doing any mods.
I don't want to hijack this thread any further so when i get it back in a week or two i will post in it's own thread.
Hopefully it's a straight forward process!