I have an old Toshiba CRT HDTV that seems to have blown the vertical hold. It just shows a horizontal line of picture. I'm hesitant to throw it out because it did cost a lot back in the day and if it worked, it could give adequate service for some time to come.
Do you know of any company that still does CRT repair? Preferably in house since I can hardly move the monster and preferably in Toronto.
What is the size of the CRT? They were typically under 40". It would not likely be cost-effective to repair that size since you can purchase a new better picture quality TV for about the same price as a repair, especially in-home.
If you had a model number I could probably advise better.
Often Vertical output amplifier failures are actually pretty simple to fix
If it were mine, I would probably try to fix it.
Over the years, I have fixed many TVs having the same issue without any documentation.
There may be a couple electrolytic capacitors in the vicinity of the vertical output amplifier that have failed.
Try replacing the vertical output amplifier IC and supporting capacitors in the area. You can usually identify the vertical output amplifier, and search for a datasheet where you'll see a schematic of a reference design.
The vertical output circuit in yours will likely be very close to the reference design.
The examples in that link are just that, only examples.
To get more specific than that you will need a model number, or open up yours yourself and start taking some of your own good pictures so we can see what you have there.
Thx, and with that I was able to find a service manual for your TV online. If you would like a copy of it send me a PM, and I'll reply with a link to it.
The vertical deflection IC is part number LA7846N
You can buy a new IC on ebay for ~ $5 to $10
I would remove the rear cover and look for that IC. It is located in one corner of the Power/Deflection Board. If the AC cord is in the left rear of that board, then it will be near the left /front of that board. Possibly mounted to an aluminum heat sink.
Once located, look in the immediate area for signs of failed electrolytic capacitors. Typically, but not always bulging at the top.
And here is a datasheet from SANYO for the suspect IC, LA7846N
When replacing the Vert Output IC on other TVs in the past, occasionally I have also found bad capacitors in that circuit.
Where the Vertical Deflection Yoke plugs in to that board, the connector and board traces are probably pretty thick.
Meaning, designed to carry some good current. Occasionally with thermal expansion & contraction over time, that solder
connection can fracture.
I think everyone can recall the days of Whacking the side of the family living room TV to temporarily fix that?? If so, that was the issue
So give it a good visual inspection. Sometimes have found that's all that was needed, touching up cold solder joints at that connector, to restore the vertical deflection. If nothing intermittent like that, then it's most likely the IC and/or the associated passive components in that area, like bad caps.
Be aware that these old CRTs carry very high voltages in places and are really not recommended for DIY repairs, unless you're either a professional or a knowledgeable amateur.
LOL, When I got older, my mother would tell this story... When I was 8 or 9 home from school ill, she found me behind the family TV drawing arcs from the "Anode Button" on the family TV with a screwdriver.. "Hey Mom, look at this...." She was very cool calm and collect... But right then she knew where I was going...
^My Dad scared the hell out of his electronics teacher by wetting a finger and touching the live capacitors (he has a strong resistance to electricity)
yeah, large aluminum caps were always fun too.
When it turned in to me fixing her dishwasher, washing machine, dryer or boiler for her, instead of calling in the "repair man", Mom learned to live with my curiousity.
The cheapest option would be to toss/recycle the existing set and find a comparable model on Craigslist/Kijiji for next to nothing. Many are even being given away for free.
I would absolutely NOT throw this television out if you can find someone to repair it for a reasonable cost. I've yet to see any new display technology that rivals these HD CRT based TVs. We've just become used to watching inferior images. I've seen the latest Sony broadcast reference monitors and, although they are nice looking, the CRTs blow them away.
Back in my high school electronics class, there was high voltage capacitor, about the size of a gas can. We'd charge it up with a neon sign transformer, rectified through a TV high voltage rectifier. It would let out a loud band and bright flash, when discharged with a screw driver across the terminals.
BTW, I was also frequently fixing TVs. I used to do baby sitting back in those days and on occasion the parents would come home to find their TV working better than before they left.
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