Packard Bell 17VT1
 

Subject: CRT Testing

I would never have thought of acquiring this set, but a friend (I’ll call him Philo) rescued it from someone who was putting it out with the garbage. He plugged it in and the screen lit up, so he shipped it to me. For free, I’ll try to put the set in working order. Philo will get a kick out of that.

I’ve pulled the chassis, and all the parts are there. The only shipping damage is one broken tube and a broken escutcheon, both easily repaired or replaced. And the yoke is loose on the CRT neck.

My next step will be to check continuities to ensure other significant components aren’t dead. I’ve tested the tubes, including the CRT.

I’d like an experienced person to assess my test results on the 17AVP4. With a Beltron 8080A, 6.3 heater volts:

No shorts.
Ten seconds to reach 0.45mA.
After four minutes, it reaches 0.55mA or maybe 0.65mA.
Interrupt: Current immediately decreases, reaching almost zero in seven seconds.

https://c1.staticflickr.com/5/4213/3...48a1377d_z.jpg

So, before I spend any time on this set, what can I expect from the CRT?

Thanks all,
Henry

How long did you have thee CRT running on the tester ? I like to leave them run 30 minutes to a couple hours to "wake" them up. Often emissions, cutoff and life test will improve.

Thanks. I only ran it five or ten minutes. I'll run it for a couple of hours this afternoon and see what I get.

I checked the heater voltage from the 8080A. It was probably 6.7 volts for the previous test. I adjusted it to 6.3 volts and ran it for 90 minutes. This time it took about 2 minutes to peak at barely over 0.2 mA, then slowly decreased to 0.15 mA where it stayed for the entire test period--then dropped to less than 0.05 mA in a few seconds.

Entirely hopeless? Even if it's hopeless I'm going to play with the restorer just to see if the meter and indicator lights work.

After you let it "cook" for a while, if it's still really weak, you can also try running it at, say, 8V for 10 minutes, then put it back down to 6.3 and test it again. Has worked for me. Only time I tried "restore" was on a Trinitron, and it made it much worse, rather than better.

I left the instrument on for several hours and tried increasing the voltage for 10 minutes, but had little change in subsequent test results. Then I ran the restoration procedure one time. After that the test meter rose promptly to .85mA, the minimum "good" result. When the voltage is cut, it only held that current for two or three seconds. I repeated the test two days later with the same outcome. So, I'll proceed with the electronic restoration and hope for the best.

Since you've got the Beltron, run a clean cycle on the tube. Won't hurt a thing and it's very likely to bring that tube right back, even without running a full restore cycle on it. I just can't say enough about Beltrons. :banana:

After reviewing my personal notes and retrieving deleted email, I now recall that I ran a cleaning cycle first without even a flicker of the lights, then did one restore cycle. That's my story and I'm sticking to it!

That is normal. Do you have any idea how many tubes you'd need to clean at once to make all the lights in your house flicker? :D

If you knew me better, you’d realize that I might take down the entire power grid by changing the batteries in a flashlight. (Just ask my wife what happened the first time I tried to fix a toilet.)

Starting on the Packard Bell 1956, 17-inch, B/W.
 

Well, it only took me six months to get back to this. I did a quick repair on the escutcheon and reassembled it for photos.

https://farm5.staticflickr.com/4703/...5b342fb5_z.jpg

.
. It's a 1956 Packard Bell 17VT1--a cube with a rectangular CRT in front, knobs on one side, and a simulated wood finish. Chassis V8-1.

https://farm5.staticflickr.com/4666/...4e7b6d0f_c.jpg

https://farm5.staticflickr.com/4678/...5987077f_c.jpg

Before I pull the chassis again, I have an opening question:

Should I pull the CRT first to start the chassis work?

Thanks,
Henry

Henry, it would certainly make life easier. But the question is are you up to reinstalling the CRT and all that goes with it?

Your call...

Thanks. Did that last night. Only had to cut six (clearly colored) leads from the yoke. Yoke, ion trap, etc. stays on the neck. The yoke is loose anyway.
- Henry (formerly of Indian Head, Silver Spring, Baltimore, Columbia, and Frederick)

Sometimes if the yoke does not slide off easily over the base cap, a little gentle heat from a hairdrier is helpful.

jr

kvflyer, AKA Don Cavey. Worked C&P Telephone, Columbia, Arbutus, Cockeysville, Manor, Essex, etc. Now retired in for 15 years ... Fernandina Beach, Florida! No snow to shovel.