Sony KV-27S42 Black screen and blinking standby light

[grossbard]

I've been in the process of recapping a Sony KV-27S42. I first recapped the power and horizontal sections and it was working great. The other night I recapped the vertical section and also several caps near the jungle IC.

Now when I turn on the TV, I get high voltage but just a black screen with a constantly blinking standby light. The remote still turns the TV on and off, but I get no OSD or picture. If I turn up the G2, I can see retrace lines. I can't test if the sound works, because the sound stopped working on the TV a while back.

I double checked that all the caps I put in were the correct value and polarity. I measured the cathodes and get 200v on each one.

I looked for cold solder joints but didn't find anything obvious. I reflowed several points just to be safe.

From what I read in a Sony training manual I found somewhere online, a continuous blinking standby light means no jungle IC communication. Is the jungle fried?

[zeno]

Check the data line to the jungle with a scope for activity.
If none unsolder the data line for the tuner & any other place it goes.
We had shorted tuners cause your symptom or very small scrambled
pix.

73 Zeno
LFOD !

[grossbard]

Zeno, first of all thanks for always being helpful. I've learned a lot just by lurking on here and reading your posts.

Unfortunately I don't have a scope and I'm quickly realizing that if I want to get very far in this hobby I'm going to need to get one!

If it does turn out the be the tuner, can the TV be operated without one? I only use this tv for games and from what I've seen replacement tuners are pretty expensive.

[zeno]

Originally Posted by grossbard

Zeno, first of all thanks for always being helpful. I've learned a lot just by lurking on here and reading your posts.

Unfortunately I don't have a scope and I'm quickly realizing that if I want to get very far in this hobby I'm going to need to get one!

If it does turn out the be the tuner, can the TV be operated without one? I only use this tv for games and from what I've seen replacement tuners are pretty expensive.

If you unhook the data line & the tuners bad I would think it would work on
the inputs. If you have a manual there should be DC measurements that
are an average of the data. In your case I would especially watch for a
solder splat, bent over wire or hair line crack.

73 Zeno

[grossbard]

I removed the data line from the tuner by removing the series 100 ohm resistor and the TV is still showing a black screen (with retrace lines if I turn G2 up enough) with a constantly flashing standby light.

I am getting around 5v on the jungle IC data pin, and 9v on both VCC pins. Not really sure what else to try without a scope. I've gone over the board several times tracing out circuits and looking for cracks, cold joints etc. I think i'm going to order a replacement jungle IC and try that next...

[grossbard]

I replaced the jungle. No effect whatsoever, still the same issue.

I noticed pin 21 on the jungle (IK) was reading around 400mV when it should be 1.6 according to the service manual.

I may have to find a place to store this till I get a scope...I really REALLY don't want to trash it!

[dieseljeep]

Originally Posted by grossbard

I replaced the jungle. No effect whatsoever, still the same issue.

I noticed pin 21 on the jungle (IK) was reading around 400mV when it should be 1.6 according to the service manual.

I may have to find a place to store this till I get a scope...I really REALLY don't want to trash it!

No indication as to your location!
If you're close to WI, you can have one in perfect condition, maybe two.

[grossbard]

I am located in OK, which is pretty far away Thank you though!