Sony KV-2643R score

[freakaftr8]

Originally Posted by maxhifi

Her idea of perfect, and your idea of perfect may not be the same thing. That said, it's great to hear you got it going!

Yeah, I thought of that too.. But before I started, there was literally no red and barely any green. Unfortunately I didn't snap a picture before I got to work of this condition. Everything was very "smurf like" faces were literally blue. But, yes I agree, it's hard to remember details with the human mind ranging that far back.. luckfully she told me she plugged it up in the garage to see if it worked to decide whether she would sell it or give it away and that's when se noticed the raster was all blue. Hence the not working sign on it.

[Electronic M]

Originally Posted by freakaftr8

Ok. I have been reading back on old posts.. There was a discussion between a few members about "Econoquick"..

This design is meant to leave a few volts at the heaters when the tv is off, not half, or full voltage. I have a feeling that Sony designed this device while the energy crisis of the 70's was in full swing. Sony probably knew something.. If they couldn't get away with half voltage cause of the guidelines introduced then, they could with econoquick. Something at least had to be there at all times to keep the cathodes clean. My theory is If a Trinitron CRT is put into use, it cant sit for a while dormant with no filament activity or the cathodes will become corroded.. The fact that people probably may have been worried about energy consumption, they may have unplugged the set often while not in use, possibly drastically reducing the life of the CRT. This set set for 25 years stated by the previous owner. She recalls that the picture was perfect before it was put out of service just to replace it with a projection tv. It sat in the garage since unplugged.

Actually it is the opposite....If the heater is ran for a prolonged time without beam current the cathode will develop an emission blocking layer faster. This problem was especially an issue in early tube based computers where the heater of a triode in a latch might be ran full tilt for hours with no cathode current. Any CRT can "fall asleep" (develop an emission blocking layer on the cathode) from sitting unused for several years. A good reason to run your sets periodically.

My recommendation: if you are going to use it daily and want picture fast then the ecconoquick is good, but if you are not using it regularly unplug it or switch off the power strip it is plugged in to to reduce CRT wear.

Your chassis derrived rejuvenation is fascinating... I may have to try that on one of my Trinitrons at some point.

[maxhifi]

Originally Posted by Electronic M

Actually it is the opposite....If the heater is ran for a prolonged time without beam current the cathode will develop an emission blocking layer faster. This problem was especially an issue in early tube based computers where the heater of a triode in a latch might be ran full tilt for hours with no cathode current. Any CRT can "fall asleep" (develop an emission blocking layer on the cathode) from sitting unused for several years. A good reason to run your sets periodically.

My recommendation: if you are going to use it daily and want picture fast then the ecconoquick is good, but if you are not using it regularly unplug it or switch off the power strip it is plugged in to to reduce CRT wear.

Your chassis derrived rejuvenation is fascinating... I may have to try that on one of my Trinitrons at some point.

Almost every TV I've had the pleasure of working on, which has sat a long time since last being used, had a dramatic increase in emission, and stabilization of color tracking once I let the CRT sit at 8-9V for a while. Sometimes it stays that way, sometimes it drops right back down after it has been off a while.

[freakaftr8]

Absolutely agree. Most of the vintage color sets I've picked up showed weak sleepy emission. the 8v overnight trick brought most back to life into the green.

As to Electronic M, yes I always thought that any heater without cathode use causes oxidation. I just dont understand why Sony would make a big deal of econoquick if the SS circuitry was a 8 to 10 second wait from dead cold anyway.

A far leap from a non instant on full vacuum tube tv that took 30 or more seconds to produce picture, in which yes, instant on reduced CRT life and vaccum tube life as well.

[zeno]

A few notes on all of this.
Econoquick is just a fast warm up CRT. No STBY voltage.

Almost all SS sets WITHOUT a power transformer use a flyback (FBT) winding
for the CRT filament. Some sets ground on end & others "float" it at apx 130V.
This is to keep the F & cathode close DC wise to reduce arking & H-K shorting.

Service notes.
Always look for cold joints especially if the set has a PCB for the CRT socket.
Early RCA in line CRT sets used a spring contact socket. Many had toasting & went intermintant ( RCA, Admiral, Maggy, Sears/Warwick ). The plastic key on the CRT would melt & the contacts burn. Repair was a new socket, remove key, clean & bend F pins out slightly then put the key back on.

Sets with H-K short & grounded F.
There was a rash of Sanyo built Sears with Sylvania jugs that shorted H-K.
This coinsided with mass failures of the Z0064 HV rect, divider that kept us quite busy ! They used a grounded F configuration. Repair was to isolate the
F from ground ( cut etch & run a wire). Place a 1.5 meg resistor between
the shorting K & f. Also add IIRC a .01 cap from the K to ground. This made the set usable again but you could still see when it shorted in the pix.
$50 sure beat a new set for the customer !

Low E. Caution some risk !!!
You should use a scope for this ! Measure the P-P filament first. You want to
increase the F about 20-25%. Most sets have a low value resistor in series
with the F ( apx 2 ohm 1 W ). Jump it out & watch the scope for the change in P-P.
Early sets had an "open" FBT with the core for the pulse winding exposed.
Try adding a turn to the F winding. Use the scope to watch the P-P. Again not
a perfect solution but sure beats a new CRT !

Instant on.
One of my biggest beefs. Instant on is a killer especially on all tube TV's from
all MFG's. All of us are quick to condemn it. BUT on SS sets its a different
story IMHO. Ask anyone here what CRT holds up best from the 70's. 90%
will answer Zenith chromacolor jugs. The flat chassis & E line CC2 sets both
had instant on............

I am tired, nuf sed fer now
73 Zeno
LFOD !

[freakaftr8]

Well I found a 220k ohm resistor on the H2. There is an H1 and H2. Obviously I cant read with a DVM. Could you elaborate on this low value resistor jumping?

Essentially increasing heater voltage it sounds.

I still have a focus issue on the outside perimeter of the CRT I cannot achieve with dialing focus around. also blue and red smearing from weak R and B emission although it retains good brightness and contrast even with the smearing with my chassis derived rejuvenation. lol

I know it's most likely a weak crt, just surprised it can retain a really bright raster with quite a bit of contrast, not like the usual Trinitron weak crt.

But it does exhibit the smearing as contrast level goes up. And quite a bit out of focus around the perimeter.

[freakaftr8]

Ok. I gave my homebrew crt rejuvenation by cranking up R,B,G drives, screen g2 and sub brightness and sub contrast one more go just for the heck of it to try to bump this sleepy CRT awake since I wasn't happy about the red and green smearing issue I was having since the picture level had to be at a less than adequate level to make the smearing livable. I figured what do I have to lose, after all it was free.

So for 2 hours I let it cook like this in the garage to the intro to Family Guy where I saw it the worst.. After about 20 minutes I saw some red background flickering, then it gow worse. All the sudden the red bloomed in like crazy, then faded back to normal.. The red smear became green. 5 minutes after that, the green did the same thing, then the green smear dissapeared.

So I backed everything back down to midrange after letting it cook for another 1.5 hours.

What I found is if screen G2 is all the way up, sub brightness all the way down, this eliminates 90 percent of the color smearing.

Still convinced its a weak crt.

Btw, anode HV is right at 28.9KV. Reference decal says 29KV
I also looked over the neckboard for solder cracks.

[zeno]

Wrong resistor. It should be just a few ohms. If not on CRT PCB trace the F
wires back to the FBT. It also may not be there at all.

Originally Posted by freakaftr8

Well I found a 220k ohm resistor on the H2. There is an H1 and H2. Obviously I cant read with a DVM. Could you elaborate on this low value resistor jumping?

Essentially increasing heater voltage it sounds.

I still have a focus issue on the outside perimeter of the CRT I cannot achieve with dialing focus around. also blue and red smearing from weak R and B emission although it retains good brightness and contrast even with the smearing with my chassis derived rejuvenation. lol

I know it's most likely a weak crt, just surprised it can retain a really bright raster with quite a bit of contrast, not like the usual Trinitron weak crt.

But it does exhibit the smearing as contrast level goes up. And quite a bit out of focus around the perimeter.

[freakaftr8]

The H1 and H2 wires connect directly to the flyback via pigtail connector.

[freakaftr8]

Ok. Found out my HV probe is messed up possibly. what I thought was 28.9k is actually reading 15k. It's a bk precision HV-44 probe. The damn needle adjustment was cranked up and didn't realize it. Once I calibrated it back to zero, this is what I'm seeing. Doubt the tripler is actually only putting out 15k when the set requires 29kv. Is there something I'm missing?

Could be my meter. Bout to go check some vintage sets of mine to be sure.

[freakaftr8]

Huh.. My probe measured a Zenith I have the back off at 24kv. Tvs rated at 25kv. Now I'm wondering what's up. Maybe this is the reason for such poor focus? But still convinced the crt is worn out. 710AB22 is just one of those duds.

[zeno]

Originally Posted by freakaftr8

Huh.. My probe measured a Zenith I have the back off at 24kv. Tvs rated at 25kv. Now I'm wondering what's up.

Strange. Cant imagine getting a decent pix at so low HV. Maybe you are not quite hitting the metal ? Fold up the boot & be sure. NOTE most Sonys have
a coax HV lead. The outer is HV & the inner goes to the H-STAT control.
The inner makes contact to a small spring on the CRT. If you dont use the
removal tool you can loose or bend the spring. Remove the 2 HV claws
first then pull strait off. Dont use the bend & rip off method !

73 Zeno
LFOD !

[freakaftr8]

Think my probe is shot. The needle is sticking. looking for a replacement. What's the best way to adapt my sencore cr161 to read how bad this CRT actually is? Thinking of using some wires and alligator clips. What do you guys think? I know I need heater, ,R,G,B, g2 and g1 and ground right? I'm not aware of the stripe colors on the jig? Do I need to use those or just the common colors?

Its putting out a mediocre picture with sub brightness down, and screen drive turned all the way up surprisingly. just out of focus around the outer areas. Wont come in at all. Center of the raster is clear as a bell and the smearing is gone while over driving the G2.. But I can tell the tube is weak.

I know now that the filament voltage is 6.3v ang G1 is 50v. Would use a socket CR-37 but I dont have one.

[freakaftr8]

Ok so heres my setup. I used an old BK 465 to run the juice to the filaments. I unplugged the AC filament feed from the socket on the mainboard, then connected it to the BK via one of the sockets, and monitored by DMM. Honestly there is little difference besides some of the color saturation gets a little better and whites stand out more and gets brighter but nothing huge. Focus still sucks wither it's set at standard 6.3v or up to 8v.

[maxhifi]

Originally Posted by freakaftr8

Ok so heres my setup. I used an old BK 465 to run the juice to the filaments. I unplugged the AC filament feed from the socket on the mainboard, then connected it to the BK via one of the sockets, and monitored by DMM. Honestly there is little difference besides some of the color saturation gets a little better and whites stand out more and gets brighter but nothing huge. Focus still sucks wither it's set at standard 6.3v or up to 8v.

Sounds to me like you should dump this thing and focus on your CTC39