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  #31  
Old 05-07-2010, 03:26 AM
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Holly Molly, the doores are opening by the push of an buton?
The tv is ... more then awsome!
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  #32  
Old 05-07-2010, 08:06 AM
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That is so cool! I hope you get the horizontal output issues solved soon. I do have a request, if there are controls behind the door on the TV can you please take a picture of them? (I mean the door with the Trinitron logo on it.) I see that you can adjust brightness/color/hue/pix with the remote but I'm assuming there are other controls like sharpness, add/delete, cable/norm, tv/video and possibly audio controls that are only on the set. Thanks!
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  #33  
Old 05-07-2010, 09:19 AM
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Last edited by andy; 12-08-2021 at 04:40 PM.
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  #34  
Old 05-07-2010, 10:55 AM
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Out of all the TV's that I've worked on, I too have only seen one bad HOT that wasn't shorted. It was in a late '90's 32" Sony that had no HV. This was a set that I'd already replaced the HOT and power supply parts in, several years earlier. When it lost it's picture, the owner simply gave it to me. Anyway, I checked everything and couldn't find out why I had no HV. Finally, I fired up the scope to discover that I had a proper horizontal drive waveform at the base of the HOT. I replaced the HOT and all was well. The old one simply would not work, despite the fact that it checked good.
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  #35  
Old 05-07-2010, 11:15 AM
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Good call, I got the scope out last night and was going to check for a waveform, but I just got too dang tired. So tonight i'll give it a go and see what I get.

Ill snap off a pic of the controls behind the panel tonight and post.
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  #36  
Old 05-07-2010, 11:50 AM
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Quote:
Originally Posted by freakaftr8 View Post
Ill snap off a pic of the controls behind the panel tonight and post.
Thanks! Much appreciated.
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  #37  
Old 05-07-2010, 01:39 PM
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That set is a real beauty. After I saw your pictures, I remember going with another tech to a customers home one evening to work on their TV like this. I was in awe of those doors opening!

I hope you get that bad boy running!

I have an old KV-27EXR25 with a new-ish kine. It was dropped before I got it, and got a 7 inch crack across the main board between the FBT and the power supply connections to the G board. I flexed the board slightly and it snapped the crack closed. I spot glued the crack away from traces, then bridged every broken trace. Took many hours to fix, but it works, and has been trouble free, except for an IC on the G board that died due to heat, and having to replace the kine last year.

Again, I cant wait to see a picture on that machine. Due to the weight, it may be with you for the rest of your life!

Last edited by holmesuser01; 05-07-2010 at 01:43 PM.
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  #38  
Old 05-07-2010, 06:29 PM
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Yeah, wish the guy that cracked the board before would have straightened it out before resoldering the cracks. But oh well.

Here is the pic of the controls behind the door

http://i845.photobucket.com/albums/a...6/DSC01697.jpg
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  #39  
Old 05-07-2010, 08:38 PM
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Well what I thought was an issue turned out to be one. I have a funky sine wave coming from the base of the CONV transistor Q514 so I tested it and it has ashort from B to E and C to E. I noticed it gets warm quickly too. So I pulled it and pulled the HOT too. HOT is fine and compared readings to the CONV and yep the CONV is shorted indeed. Everything else so far checks out. I think that bad solder joint on the connector I talked about earlier killed the transistor. The connector goes into the conv circuit.

In turn I have no power in the HOT circuit. No waveform whatsoever coming from B of HOT. Once I restore the CONV circuit I think I should restore power to the HOT side. Keepi g my fingers crossed.
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  #40  
Old 05-08-2010, 07:22 AM
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Quote:
Originally Posted by freakaftr8 View Post
Yeah, wish the guy that cracked the board before would have straightened it out before resoldering the cracks. But oh well.

Here is the pic of the controls behind the door

http://i845.photobucket.com/albums/a...6/DSC01697.jpg
That control panel is epic. I love the individual external vs. internal A/V switches. That way you could hook up an FM tuner to the stereo audio input for simulcast reception. The Sound Carrier switch is interesting too. I'm assuming there were different sound demodulation options available for better sound vs. better selectivity? It's also interesting that they included a vertical hold control. I suppose that was to improve compatibility with VCRs, home computers, video games, etc.
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  #41  
Old 05-08-2010, 12:35 PM
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I noticed that the vert hold was analog controlled throuout the mid 80's. Iv'e seen even a very few early 90's sets with vert hold. Sometime in the early 90's Tv's went full hold control automatically. With Sony's I think 1984 or so was it for vertical hold.
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  #42  
Old 05-08-2010, 09:31 PM
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My 1991 KV-27EXR25 has no vertical hold. I have never seen it lose vertical sync in all these years. My big RCA roundie will roll once on any source change, and likes to roll now and then when playing VHS.
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  #43  
Old 05-09-2010, 01:38 PM
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You should have the schematic tomorrow, unless it came Saturday... I got it out to you on Friday afternoon; sorry for the extra day. Let me know if you need any additional pages... I sent all of the block diagram and all of the schematic, but left out the owners manual and parts list pages this time due to a paper shortage in the house . (the manual total is 108 pages). I wish I'd been able to get it out Thursday, as I bet it would be saving you time right now.

Charles
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  #44  
Old 05-09-2010, 01:42 PM
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REAL TVs have TUBES!
 
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Quote:
Originally Posted by holmesuser01 View Post
My 1991 KV-27EXR25 has no vertical hold. I have never seen it lose vertical sync in all these years. My big RCA roundie will roll once on any source change, and likes to roll now and then when playing VHS.
Yours is in the service menu (tagged VFRE)... Very stable as a rule, but I've had to adjust vertical and horizontal hold (HFRE) on those sets a few times.

Chalres
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  #45  
Old 05-09-2010, 03:12 PM
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Yup, I learned early in life the "display, 5, vol up, power" lol
Sweet Charles, Ill be looking for it and thanks so much for printing that out for me!
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