GE 14" Safety Question

[JohnCT]

Okay, time for one of Johnny's boring old timey stories:

My dad told me the time he was hanging around the parts counter of his favorite parts supplier (they had the best coffee) and a service man walked in the door with an unboxed picture tube in his arms. He didn't like to pay for the dud (that's what we called the core charge in the old days) and then have to return the dud for credit, so he brought the tube in bare to exchange in the carton right then and there.

As he walked towards the counter, a loud snap was heard and the guy tossed the tube straight up in the air. Dad says everyone hit the dirt like a grenade was tossed, but I think he was just reliving his war years.. Anyway, the guy caught the tube basket style that would have done Willie Mays proud and a tragedy of unimaginable proportions was avoided.

John

[Jon1967us]

Originally Posted by Electronic M

It's series heaters so you have to short the heater pins or connect a dummy load resistor of correct value (which you compue the resistance and power of based on the current and voltage spec of the CRT heater on the CRT data sheet.

One option to service this set is to remove both the CRT and chassis from the cabinet then connect the 2 on the bench. If you have a long length of spare HV wire for the HV lead you could extend the HV and yoke leads to reach into the cabinet with the chassis outside the cabinet and use the sets own cabinet and CRT as a test jig for it.... probably good to put any floating HV connections in a glass jar or mug to prevent arcing.

Couldn’t you just back the crt into the chassis, with anode and yoke connected, when both are outside the cabinet? Just park the crt where it was minus the cabinet, or am I missing something?

[Eric H]

Situations like this are why they had Test CRT's.
For a set like this the 8XP4 would be used.

[DavGoodlin]

Originally Posted by JohnCT

Okay, time for one of Johnny's boring old timey stories:

My dad told me the time he was hanging around the parts counter of his favorite parts supplier (they had the best coffee) and a service man walked in the door with an unboxed picture tube in his arms. He didn't like to pay for the dud (that's what we called the core charge in the old days) and then have to return the dud for credit, so he brought the tube in bare to exchange in the carton right then and there.

As he walked towards the counter, a loud snap was heard and the guy tossed the tube straight up in the air. Dad says everyone hit the dirt like a grenade was tossed, but I think he was just reliving his war years.. Anyway, the guy caught the tube basket style that would have done Willie Mays proud and a tragedy of unimaginable proportions was avoided.

John

We can all share our stories in any applicable thread. I ALWAYS think about this when I handle a bare CRT! Zap and bang stories like this are endless, so keep them coming!

[JohnCT]

Originally Posted by DavGoodlin

We can all share our stories in any applicable thread. I ALWAYS think about this when I handle a bare CRT! Zap and bang stories like this are endless, so keep them coming!

I have to pace myself Dave! I grew up in the business and could write a significantly sized book of stories from the trenches, but I'd like to contain myself to one every month or two. Certain threads will ping a long buried memory. Some day, someone will comment on constantly blowing fuses and I have a beauty ready to go..

John

[Jon1967us]

This TV does have a fuse, right after the AC interlock. It lists it at 1 6/10 Amp. I'm thinking of putting a thermistor after it.

Ok now you can go ahead with your fuse story...

[JohnCT]

Originally Posted by Jon1967us

This TV does have a fuse, right after the AC interlock. It lists it at 1 6/10 Amp. I'm thinking of putting a thermistor after it.

Ok now you can go ahead with your fuse story...

Rat.

Okay, this took place in the early 80s on a Zenith System 3 (which doesn't really fit this section). I was on a house call when I found the 4A slow blow fuse blown on the 9-160 power/sweep/HV module. Zenith guys know that when the 160 had a blown fuse, you swapped the module out - changing the fuse was a waste of time.

Meanwhile, the customer is all over my shoulder saying it must be the fuse - that's all it needs. I told him that a blown fuse in this board meant problems, but he wasn't convinced, so I found the biggest fuse I could find in my tool box which was an 8 amp IIRC.

I snapped the fuse in the holder, plugged the TV in, and had the customer get down near the fuse and keep a *real* close eye on it so he could tell me if it blew. I walked around the front of the TV and pushed the power button. I could hear the telltale soft pop of a blown fuse and the silhouette of the guy against the wall for a split second.

I asked him if the fuse blew. He came out from behind the TV wide-eyed. I'm sure he saw that flash every time he blinked for the next half hour.

He didn't question the replacement 9-160 board after that.

John

[Jon1967us]

Haha
Keep a REAL CLOSE EYE on it

[Electronic M]

That fuse story is a hoot...I was kind of expecting fire and or a transistor to splode given the biggest fuse I could find line...

Originally Posted by Jon1967us

Couldn’t you just back the crt into the chassis, with anode and yoke connected, when both are outside the cabinet? Just park the crt where it was minus the cabinet, or am I missing something?

Yes, that is what I described in the first sentence of the second paragraph...the rest of the paragraph was describing lead extensions for if you wanted to keep the CRT in the cabinet.

[alok]

This may have been mentioned already or you may be familiar with HOT CHASSIS ,depending on how AC plug is in power outlet. These type TV's ,GE and others had a bad reputation in the 50's /early 60's for chassis that were hot and that shock hazard transferred to the metal cabinet in some cases.
There were even deaths reported caused by this problem on GE's in particular ,the feds investigated along with UL.

Check and recheck when you put this set back together.
Be careful

Al

[Jon1967us]

Alok

Thanks for the reminder. It's something that has been on my mind and a concern. This danger is shared by some of my other TVs of the same vintage and I intend to check all of the spacers/insulators as well as voltage checks for hot cabinet to ground.

I have another set, a Travler, where the metal bracket that holds the CRT is tied to the cabinet, which concerns me greatly as the metal "collar" that fits around the CRT neck makes contact with the dag coated outside of that tube. There would've been rubber between this bracket collar and the CRT but it is shrunk and petrified.

I bought a roll of fish paper at the local electronics parts place and I plan to use this to insulate any potentially dangerous contact points. We'll see.

[Electronic M]

Chassis isolation on these GE is adaquate...can always check megaohm range resistance between cord and cabinet if you're worried.

I just modified a Zenith MJ1035W that is going to the family cabin. It used to be a hot chassis with a filament transformer now it is got an isolation transformer built in.

[JohnCT]

When my plan was to restore a 1952 GE 19" hot chassis I was going to put a GFI plug on the TV. If I see an curling iron or hair dryer at a tag sale for a buck or two I'll buy them if they have that plug. They're usually good for 1000 watts or so. Yes, they're ugly (particularly the white ones), but I usually put them on AC/DC radios if I give a restored one away to someone.

John