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Old 11-24-2018, 10:36 AM
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Electronic M Electronic M is offline
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Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 14,785
Quote:
Originally Posted by Jon A. View Post
No surprise there, most sets I've opened have the RF input cable soldered in place. In my experience those things need really good grounds. If the 1st RF amp transistor is blown it'll be a real dog to replace if even possible, it's pretty tight in there. Unless you have a schematic that identifies the transistors don't bother trying. Any tuner that uses approximately the same B+ voltage should work even if it doesn't physically fit. Fortunately for me a blown tuner was very much the same internally as one from my parts stash, the most important feature being a removable shaft. The hardest part will be swapping the front of the housing so it will mount properly.

The damage to the CRT anchoring point has nothing to do with the image size issue.
His problem is probably a dirty tuner (easy fix) versus your transistor issue (not particularly easy).

First step on any noisy tuner issue should always be clean the contacts. You should not need to remove the whole tuner from the cabinet or any wires from the tuner. Most sets made it so that you could unclip and remove the tuner shield and clean the contacts with the tuner still mounted and connected. There is a front and back to the tuner that the shaft passes through and a "top" that the wires connect to(some tuners are mounted upside down or other wacky ways so "top" is not always pointing up)...The removable shield typically comprises the bottom and sides of the tuner. It usually clips into the top. To remove pinch the sides inwards near their centers at their upper edge where they meet the "top" and pull down after you've started to pinch while still pinching...The shield should slide off. After that identify the contacts and start spraying cleaner and spinning the knob...If there is lots of room around the contacts I like to stick a soft white pencil eraser in there and let the contacts brush against it...This alone will help but if you do it while they are wet with contact cleaner you will be impressed with how much tarnish it will remove.
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