electronics, repairs, service manuals and datasheets discussion community for the repairs professionals and technicians
FAQSearchMembersGroupsRegisterProfilePM'sLogin/Out
Sony KP-57WV600 Blue CRT driver board

 
Post new topic   Reply to topic    Electronic equipment repair and service manual search discussion Forum Index -> Equipment Repairs
View previous topic :: View next topic  
Author Message
Bahdabing
Guest





PostPosted: Wed Dec 10, 2008 5:15 pm    Post subject: Sony KP-57WV600 Blue CRT driver board Reply with quote

Hello everyone. My dad bought a KP57WV600 tv that had a known convergence issue with the red CRT. I've since repaired that problem by adjusting the voltage pot for the red crt. After that though, the picture still didn't look right. Things that were supposed to be blue were greenish and things that were supposed to be white were yellow. Because of that, it appeared that blue CRT was not on. I opened up the back of the TV and sure enough, it wasn't. To make a long story short, I do have voltage to the CRT drive board, but there are at least 2 blown components on the board. So, I'm assuming at this point, the board is blown and this is the reason the blue CRT is not coming on. I'm an electronics student in my final semester at school, so I know a little about what I'm doing on the boards . However, one of the components that is blow on the board, I've never seen before and do not recognize the schematic symbol. I brought the schematic to one of my instructors along with a picture and he said he thought it was a indicator lamp. In my schematic manual, the lamp is listed as NL9302 and says 80V below it. The other component that is blown is the 1k, half watt resister that is in parallel to the lamp (R9323). The 1k resistors are easy to get a hold of. The lamp on the other hand, I'm not sure where to get it and even then, I don't know what amperage it needs to be.

So A) does anyone possible have a good CB CRT drive board p/n 1-685-260-11 board I could buy or B) does anyone have an actual part number for that lamp and/or know where I can buy that lamp and what the correct amperage is on it?
Thanks a bunch!
Back to top
jts1957



Joined: 24 Nov 2008
Posts: 2472
Location: Far, Far Away

PostPosted: Wed Dec 10, 2008 6:07 pm    Post subject: Re: lamp Reply with quote

NL = Neon Lamp.
80V if I remember correctly is the voltage it "comes on" at. It is used similar to a spark gap, for excessive voltage.
Back to top
View user's profile Send private message
vtech



Joined: 08 May 2006
Posts: 1264
Location: USA

PostPosted: Wed Dec 10, 2008 8:04 pm    Post subject: Re: Sony KP-57WV600 Blue CRT driver board Reply with quote

Bahdabing wrote:
Hello everyone. My dad bought a KP57WV600 tv that had a known convergence issue with the red CRT. I've since repaired that problem by adjusting the voltage pot for the red crt. After that though, the picture still didn't look right. Things that were supposed to be blue were greenish and things that were supposed to be white were yellow. Because of that, it appeared that blue CRT was not on. I opened up the back of the TV and sure enough, it wasn't. To make a long story short, I do have voltage to the CRT drive board, but there are at least 2 blown components on the board. So, I'm assuming at this point, the board is blown and this is the reason the blue CRT is not coming on. I'm an electronics student in my final semester at school, so I know a little about what I'm doing on the boards . However, one of the components that is blow on the board, I've never seen before and do not recognize the schematic symbol. I brought the schematic to one of my instructors along with a picture and he said he thought it was a indicator lamp. In my schematic manual, the lamp is listed as NL9302 and says 80V below it. The other component that is blown is the 1k, half watt resister that is in parallel to the lamp (R9323). The 1k resistors are easy to get a hold of. The lamp on the other hand, I'm not sure where to get it and even then, I don't know what amperage it needs to be.

So A) does anyone possible have a good CB CRT drive board p/n 1-685-260-11 board I could buy or B) does anyone have an actual part number for that lamp and/or know where I can buy that lamp and what the correct amperage is on it?
Thanks a bunch!


Can't tell you the specifics but I know that Sony's and arcing picture tubes are not unusual. Sometimes it is the tube or may be the CRT socket itself that causes that.
As it has been said, the NL9302 is simply a neon lamp with a breakover of 80 volts acting as a crowbar. It is actually acting as an open circuit and conducts if/when it sees above 80volts. If it happens to have a dark glass, does not necessarily indicate a defect however, it does shows that has been doing it's job & you have/had an arcing problem especially if the R9323 is toast. Perhaps minnie will chime in.
(the path source of high voltage is the anode of the tube arcing back thru pin4/5 of the tube to quench to ground)

Could be an intermittent or a permanent issue with the blue tube and may have damaged it's drive circuitry? I seem to recall that arcing could also mess with convergence setting. At this point, beside voltage reading, all you can do is to replace the burned resistor & try it.---may hear/see an arcing?
Back to top
View user's profile Send private message
Guest






PostPosted: Tue Dec 16, 2008 2:34 am    Post subject: Reply with quote

I ordered a new board instead of replacing the lamp and resistor. I just installed it and as soon as power was applied, the lamp came on, and the resistor started smoking Mad Now i'm not really sure what to do. Any suggestions?
Back to top
bahdabing
Guest





PostPosted: Tue Dec 16, 2008 2:44 am    Post subject: Reply with quote

A buddy of mine came over to look at the tv. He knows a little about tv repair. He swapped the high voltage line to the blue crt with the green one. When the tv was turned on, green came on and blue still did not so looks like the blue CRT is dead? I tried looking this part up and the places I found do not carry the CRTs any more. Is there a place that will carry those or is the tv kind of lost cause now?
Back to top
jts1957



Joined: 24 Nov 2008
Posts: 2472
Location: Far, Far Away

PostPosted: Tue Dec 16, 2008 3:22 am    Post subject: Re: Bad CRT Reply with quote

Get the type number of the tube and ask local repair shops, one might have.
People abandon their sets once they hear the cost(s) to repair. Shops throw out sets if they don't want to invest in fixing them themselves.
A lot of sets will use the same tube number (especially SAME brand &/or around the same vintage).
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Electronic equipment repair and service manual search discussion Forum Index -> Equipment Repairs All times are GMT
Page 1 of 1

 
Jump to:  
You can post new topics in this forum
You can reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Електроника София - Service Manuals Free Download - Prikachi - Service Diagrams

Free TV Schematics Download - HARDW.net - Pinout Master - Jabse Search - Jabse.InK  - Pulsator

Connector Pinout Forum - Новини - SnimkiOt.com - безплатен DNS - Whois разузнаване - Poblizo.com : пътешествия