Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
John-Del
 
Posts: n/a
Default Need Sony PTV tube

I'm looking for a Sony 07MAB2 green CRT. It's from the metal chassis
light box with the over\under high voltage and power supply setup. I
have a couple of them scrapped, but the one I need uses the single
focus pin small neck tubes, while the ones I have are the large neck
variety.

Tube doesn't need to be strong, it only needs to be free from
air.......

John

  #2   Report Post  
 
Posts: n/a
Default Need Sony PTV tube

Did you give VDC in Georgia a try ?

Incedentally, a word to the wise. Put a scope probe on the PS output to
the fly, WITH ALL ANODES DISCONNECTED. One time I had an unexplained
busted CRT in an RPTV and found the 130V line going up to about 200V.
It happened pretty fast, the shutdown couldn't catch it.

Basically don't put any tube in it until you see it work with the other
two tubes. You might not be able to get video because of the AKB, but
when you get to the point where you don't hear a SNAP and crackle, then
is when you install the tube.

Having a blue tube crack is one thing, it is pushed the hardest usually
and can run pretty hot. Also as seen in NAPs the bluescreen from a VCR
can blow it up sometimes, with the family happily sleeping in front of
the set on a Saturday night. Having the green or red go like that
raises alot of red flags for me, mainly because I'm a PTV specialist.
These things have a pretty gnarly HV section and if unchecked by
regulation can do dasterdly things.

The newer line of Sonys, which you got, I'm not totally sure, but in
the slightly older ones, like the EXRs, they cannot run with a shorted
HV regulator. I do believe they gave up on that architechture when they
changed to the new line, which is when they dropped the SD (big neck)
CRTs.

At last calling, VDC could not supply the SD series CRTs, but that
doesn't mean they don't have yours. If they even have it, you are going
to have to get an OK for about $375 or so, the CRT will be at least
$200.

Actually the last CRT job on an RPTV we sold was because I got it
running with the other two CRTs and the customer saw it and said yes.

I think you can fool the AKB circuit, there was some talk of a
resistor. Another way I think if you just put about a 22K to 100K
resistor from the cathode terminal to the 220 volt supply it should
work. Seeing that much is good, then you know if you got convergence
problems etc., also you get to check the yoke. When a CRT breaks,
sometimes to also need a yoke. A coworker missed this a while back and
Leonard saved the day. It was NLA and the CRT was on the way. That was
the same set with the 200V 130 V line.

Could have had a very bad day. That's why I mentioned it. You must
disconnect the CRT socket as well as the anode, it might short out the
focus voltage or something. Leave the yoke connected of course. Along
with letting the set run, it will test the yoke. The only one extremely
improbable problem you might have with that yoke would be a shorted
vertical winding. Any other problem will cause something, whether it's
shutdown or whatever in the geometry of the other two CRTs.

This little stickler is something I learned recently, like I already
knew, but was convinced to see the picture before ordering big ticket
items. My boss used to be a tech, and says whenever possible I want to
see a picture before calling the quote.

He was proven right in spades late last year. Had a Sony, needed
whatever, I don't remember, but I told him it's up and running but no
tuner. He insisted on seeing something in the way of real video on it,
OK needs a tuner, we just grabbed a DVD player.

Sure as **** the CRT had internal damage and there were black flecks
all over the about upper half of the screen. You could not see this
with snow.Strange thing was on that set, the purity was fine. My eye is
trained enough to detect a purity problem on snow, but we had black
dot/spots. I did not see it.

JURB

Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
I dropped the tv ( Sony circa December 1985) Accidents HAPPEN Electronics Repair 18 June 22nd 04 05:54 AM
Sony picture tube Dave M. Electronics Repair 21 January 6th 04 01:38 AM
Tech Review: Victor's (8liners/Genao) Replacement Arcade RGB Monitor Chassis (LONG) Pac-Fan Electronics Repair 22 November 26th 03 12:56 PM
Sony G500 Monitor Repair bigmike Electronics Repair 0 July 23rd 03 09:01 AM
Sony G410R Monitor problem (and bad Sony support) Steeve M Electronics Repair 7 July 15th 03 12:24 AM


All times are GMT +1. The time now is 06:09 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"