CRT gun pin fell off

[pentium]

Kinda hard to explain what happened here but anyways, while I was pulling the tube from my TRS-80 model II I removed the connector at the neck of the tube which goes to the gun and such and one of the pins popped off with it. I heard no hiss and the tube was fine beforehand and by the looks of it the solder joint has just gone cold and let go of the pin. Is there any way to resolder the pin back in?
I have heard of this happening before but it was mentioned in a 1955 issue of Radio Electronics and this is no Emerson TV set I'm working with.

[Wizard]

Re: CRT gun pin fell off

Which? CRT's pin or the CRT socket?

You can find and salvage any 12" monochrome CRT monitor if you can find one.

The best one is amber.

Reason I say another CRT tube is the pins is non-solderable and is made of soft steel, it is surprising that pin seperated in two. I carefully wiggle CRT board off with gentle pull.

There was one incident where I was fortune to have a bad CRT with a HV silicone had permenantly glued CRT socket so I simply ordered new socket and a replacement CRT and did this. Was warranty job and my boss and coworker was impressed because I knew no way that would get socket off. it's on for GOOD and that how stuck.

Cheers, Wizard

[pentium]

Re: CRT gun pin fell off

Well for starters it's an RCA 12VCLP4 black and white tube and (this is where I'll correct a badly worded sentence) and I'm missing one of the pins on the stem. As I was pulling off the socket the pin went with it.
You sure there is no way to reattach the pin? Looks like it used to eb soldered in place.
Also, I have not discharged the tube yet. Like almost every CRT tube, I don't know how to do it to the point I can go and remove the flyback cup.

[Wizard]

Re: CRT gun pin fell off

I have as I said. This is very standard monochrome CRT, preferably amber 12" CRT with IIRC small 9 pin.

I have done this even it is not RCA. Get it from a 12" TTL monitor.

Cheers, Wizard

[pentium]

Re: CRT gun pin fell off

Where exactly am I to look?
I can find a tube anywhere but from what I understand, just any black and white 12" CRT tube will not do. It has to not only be pin compatible but within specs. Would pulling a 12" b/w (or amber or green or red if they sadistic enough to make those) tube from any TTL monitor really suffice? That sounds way too easy for something that's almost 30 years old.

[Wizard]

Re: CRT gun pin fell off

Yes.

Just look inside wtih your flashlight to see if the neck is thin like yours. Yoke you swap from old CRT to replacement CRT.

Cheers, Wizard

[pentium]

Re: CRT gun pin fell off

Doesn't a yoke require precision alignment?
I'm asking so many questions becaus come on, this is the first time I ever messed with a CRT tube.

[KeriJane]

Re: CRT gun pin fell off

Hi Pentium

I used this stuff once to put the wire back on my car window defogger:
http://www.crazypc.com/products/cond...poxy-9101.html

2-part epoxy solder! It actually held the wire connector thing back on the window glass AND the defogger works again.
It looks like solder after mixing and seems to work great.

If it can carry the heavy current for a window defogger AND last through Chicago Winters (and Summers) it'll be strong enough.
Only question is if the resistance is too high.


Good Luck,
Keri

[Wizard]

Re: CRT gun pin fell off

The yoke rotates to fix the tilt. The funny dark purplish/dark brown around the yoke on their stubs that rotates and push down and up is to fix the corner more square.

Seat the yoke all the way against CRT's bell with set of rubber wedges in 3 places, I secure the wedges with silicone RTV. Tighten real gently, just enough to keep yoke in place.

You'll get it.

Cheers, Wizard

[pentium]

Re: CRT gun pin fell off

Went to the recycler and for $6 got a suitable replacement tube from a donor MDA monitor.

[calpirro]

Re: CRT gun pin fell off

Hi,

my name is Albert, I'm sorry that my 1st post here is for asking help .... but I've bought a TRS-80 Model IV and the CRT was broken during the shipping... It's the RCA 12VCLP4 you have been talking about. Please, anybody know where could I get (cheap) one to repair my new-old computer?

Thank you very much...

[Wizard]

Re: CRT gun pin fell off

Like I suggested to Pentium, have to source a good CRT from a monochrome TTL aka MDA monitor in 12" size with this type of pins.

Cheers, Wizard

[Wizard]

Re: CRT gun pin fell off

Like I suggested to Pentium, have to source a good CRT from a monochrome TTL aka MDA monitor in 12" size with this type of pins.

Cheers, Wizard