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B&W TV A 68 year old intermittent fault finally nailed!

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irob2345
(@irob2345)
Posts: 575
Honorable Member Registered
Topic starter
 

This post concerns an Oz HMV E1-01 from 1956.

EMI Australia's first TV had a difficult birth as I have posted about before.

Does this chassis look like anything you saw in the UK?

Chassis RHS

I first saw this particular TV 8 years back and repaired it for its owner. Its CRT is the one rebuilt by AWV using  the Cossor glass after all the original Cossor CRTs failed within 3 months, along with the UK imported wax potted LOPTs.

Anyway, this one has been going just fine for the last 8 years, until its owner reported picture failure.

Sure enough, when it arrived, no picture. We pulled the chassis and I expected to see a catastrophic LOPT failure. The one that was in it was a dodgy 1960's replacement that I had repaired with hot melt glue 8 years ago. But no, it still looked good.

Unfortunately, when I fired it up on the bench it worked perfectly!

Some thumping, flexing and probing followed. I found a dry joint on the HT connection to the damper. Fixed that, put back in cabinet.

Now loss of sound when the mains input socket was pressed.

Out again, fixed fatigued resistor connections to the fuse holder strip which flexes when you push the plug in.

Back in cabinet.

No picture!

Out again, set works on the bench.

More flexing, this time with meter and clip leads in place, reveals HT is disappearing in the yoke interlock.

Now I had this problem 8 years ago, replaced the octal yoke plug on the cage, no more trouble.

Resoldered the interlock pins on the plug, I could still make it fail.

Pulled the wires out of the pins for a more thorough treatment.

And there it was, the jumper wire that had never been soldered.

Sitting there for 68 years and taunting us!

TV is on its way home with its happy owner. Who wouldn't be happy with an old TV with this picture quality?

Chassis RHS
Chassis LHS
Found you
Finished job]
 
Posted : 19/05/2024 9:10 am
LSmith, unit no 16, Jayceebee and 4 people reacted
Nuvistor
(@nuvistor)
Posts: 4622
Famed Member Registered
 

@irob2345 We had sets with a similar layout on a metal chassis, can’t say a make but the layout was very similar but of course without the mains transformer. A few years later and the 110 degree CRT were more common with a a vertical chassis some metal others PCB.

The set certainly has an excellent picture.

Frank

 
Posted : 20/05/2024 6:53 am
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