Toshiba tube shorted. Can I clear it?

[Roy and Rosa]

I have a shorted pic tube in a Toshiba 32" 32afx61 flat screen Thompson
tube.
Before I trash it how can I try to clear short? Shops want $100 bucks to
try 'with no promisses' of course. Id rather put taht money towards a new
tv.
I know trying this is a last ditch effort. The tube is shot anyway. So I
know I cant hurt it. Its only about 3 1/2 years old.
I already tried to isolate heater. The short is not to the heater.
The red gun is shorted I dont know the label of the other pins that are
shorted. It is NOT ...blue, green, heater, or G1. The 2 other pins that
are shorted to the red are connected to ground on the neck board. Looking
at the tube from the back they are from
about 7 oclock to 2 oclock. The RK is in the middle and the other 2 are are
at each end.
I tried tapping on neck. didnt help. I would like to try to burn it clear
if that is the next thing to try. How can I do that?
Thanks
Roy

 

[[email protected]]

For starters, how about telling us the code/type of CRT. 32afx61 is
not the tube type. Then, how do you know it is shorted, which pins
are shorted to which pins,etc.

 

[mike]

I have a shorted pic tube in a Toshiba 32" 32afx61 flat screen Thompson
tube.
Before I trash it how can I try to clear short? Shops want $100 bucks to
try 'with no promisses' of course. Id rather put taht money towards a new
tv.
I know trying this is a last ditch effort. The tube is shot anyway. So I
know I cant hurt it. Its only about 3 1/2 years old.
I already tried to isolate heater. The short is not to the heater.
The red gun is shorted I dont know the label of the other pins that are
shorted. It is NOT ...blue, green, heater, or G1. The 2 other pins that
are shorted to the red are connected to ground on the neck board. Looking
at the tube from the back they are from
about 7 oclock to 2 oclock. The RK is in the middle and the other 2 are are
at each end.
I tried tapping on neck. didnt help. I would like to try to burn it clear
if that is the next thing to try. How can I do that?
Thanks
Roy

I've had some interesting results with a stun gun.
Not enough energy to melt a hard short, but can smoke
a bit of debris.
mike

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[JANA]

You will need the CRT rejuvenator unit, and to know how to use it.

Since you were quoted a high price in your opinion to try to rejuvenate the
CRT, you should call around your area to find a service shop that would do
it for a lower rate.

--

JANA
_____


I have a shorted pic tube in a Toshiba 32" 32afx61 flat screen Thompson
tube.
Before I trash it how can I try to clear short? Shops want $100 bucks to
try 'with no promisses' of course. Id rather put taht money towards a new
tv.
I know trying this is a last ditch effort. The tube is shot anyway. So I
know I cant hurt it. Its only about 3 1/2 years old.
I already tried to isolate heater. The short is not to the heater.
The red gun is shorted I dont know the label of the other pins that are
shorted. It is NOT ...blue, green, heater, or G1. The 2 other pins that
are shorted to the red are connected to ground on the neck board. Looking
at the tube from the back they are from
about 7 oclock to 2 oclock. The RK is in the middle and the other 2 are are
at each end.
I tried tapping on neck. didnt help. I would like to try to burn it clear
if that is the next thing to try. How can I do that?
Thanks
Roy

 

[James Sweet]

I have a shorted pic tube in a Toshiba 32" 32afx61 flat screen Thompson
tube.
Before I trash it how can I try to clear short? Shops want $100 bucks to
try 'with no promisses' of course. Id rather put taht money towards a new
tv.
I know trying this is a last ditch effort. The tube is shot anyway. So I
know I cant hurt it. Its only about 3 1/2 years old.
I already tried to isolate heater. The short is not to the heater.
The red gun is shorted I dont know the label of the other pins that are
shorted. It is NOT ...blue, green, heater, or G1. The 2 other pins that
are shorted to the red are connected to ground on the neck board. Looking
at the tube from the back they are from
about 7 oclock to 2 oclock. The RK is in the middle and the other 2 are are
at each end.
I tried tapping on neck. didnt help. I would like to try to burn it clear
if that is the next thing to try. How can I do that?
Thanks
Roy

I've had some success charging up a capacitor to a couple hundred volts and
discharging it into the shorted pins. Start with something small, maybe 10uF
and go from there. In a pinch you can charge it from rectified AC line.

 

[Tom MacIntyre]

I have a shorted pic tube in a Toshiba 32" 32afx61 flat screen Thompson
tube.
Before I trash it how can I try to clear short? Shops want $100 bucks to
try 'with no promisses' of course. Id rather put taht money towards a new
tv.
I know trying this is a last ditch effort. The tube is shot anyway. So I
know I cant hurt it. Its only about 3 1/2 years old.
I already tried to isolate heater. The short is not to the heater.
The red gun is shorted I dont know the label of the other pins that are
shorted. It is NOT ...blue, green, heater, or G1. The 2 other pins that
are shorted to the red are connected to ground on the neck board. Looking
at the tube from the back they are from
about 7 oclock to 2 oclock. The RK is in the middle and the other 2 are are
at each end.
I tried tapping on neck. didnt help. I would like to try to burn it clear
if that is the next thing to try. How can I do that?
Thanks
Roy

What are the other 2 pins labelled as? They may be alternates for
other CRT boards?

Tom

 

[Roy and Rosa]

What are the other 2 pins labelled as? They may be alternates for
other CRT boards?

Tom

numbers on tube
The tube is Phillips tube not a thompson. Sorry bout that.
A80ERF031X13
D-9223

Im doing this from memory I could have missed a pin BUT I know the shorted
pins are the pins on the ends and the red K.
pins are numbered from 5 to 12 clockwise (not including the pin in the
'key')
none are labeled but I know what some are.

5- shorted to 8 & 12 <--- this pin in connected to ground on neck board
6- green gun
7-
8- Red gun The SHORTED one
9- heater
10- heater
11- blue gun
12- shorted to 5&8 <--- this pin in connected to ground on neck board

I'll confirm these pins tomorrow
Roy

 

[Franc Zabkar]

Im doing this from memory I could have missed a pin BUT I know the shorted
pins are the pins on the ends and the red K.
pins are numbered from 5 to 12 clockwise (not including the pin in the
'key')
none are labeled but I know what some are.

5- shorted to 8 & 12 <--- this pin in connected to ground on neck board
6- green gun
7-
8- Red gun The SHORTED one
9- heater
10- heater
11- blue gun
12- shorted to 5&8 <--- this pin in connected to ground on neck board

I'll confirm these pins tomorrow
Roy

Where are G1 (brightness) and G2 (screen)?


- Franc Zabkar

 

[Roy and Rosa]

Where are G1 (brightness) and G2 (screen)?

I rechecked the tube and Pins are correct as labeled. Pin 7 has 270+ volts
on it. There are 2 pins in the 'key' that have wires running back to the
flyback. I dont know G1 from G2 with them being labeled for me. This
flyback has 3 adjustments though...screen,and what appears to be 2 focuses
(focii?)

I was able to clear the short to pin 8 ,the red, (charged a 150 uf cap to
200 vdc) 5 and 12 remain connected. dont know if they should be.
The pics still looks pretty bad, alot of red and blue. I suppose cutoff is
controlled in the service menu huh.
No pots on board. This is the newest tv ive ever worked on!
I'll push on slowly.
Thanks for the replys,
Roy

 

[Franc Zabkar]

I rechecked the tube and Pins are correct as labeled. Pin 7 has 270+ volts
on it.

That looks like G1.

There are 2 pins in the 'key' that have wires running back to the
flyback.

Probably Focus and G2/Screen.

I dont know G1 from G2 with them being labeled for me. This
flyback has 3 adjustments though...screen,and what appears to be 2 focuses
(focii?)

- Franc Zabkar

 

[[email protected]]

That looks like G1.

I have never in my life seen such a high G1 voltage. It is most
certainly G2. In that case the voltage is a bit low, which is either
caused by the load of the voltmeter, or somehow related to your problem.

Probably Focus and G2/Screen.

Wrong again, probably. These are the 2 focus connections.

 

[Franc Zabkar]

I have never in my life seen such a high G1 voltage. It is most
certainly G2. In that case the voltage is a bit low, which is either
caused by the load of the voltmeter, or somehow related to your problem.

Sorry, I goofed badly. G1 is probably earthed on the CRT PCB, probably
via pin 5 or 12? Otherwise G1 grids are most often driven negative,
IME.

Wrong again, probably. These are the 2 focus connections.

Yeah, I missed that.


- Franc Zabkar

 

[Roy and Rosa]

..

I rechecked the tube and Pins are correct as labeled. Pin 7 has 270+ volts
on it. There are 2 pins in the 'key' that have wires running back to the
flyback. I dont know G1 from G2 with them being labeled for me. This
flyback has 3 adjustments though...screen,and what appears to be 2 focuses
(focii?)

I was able to clear the short to pin 8 ,the red, (charged a 150 uf cap to
200 vdc) 5 and 12 remain connected. dont know if they should be.
The pics still looks pretty bad, alot of red and blue. I suppose cutoff is
controlled in the service menu huh.
No pots on board. This is the newest tv ive ever worked on!
I'll push on slowly.
Thanks for the replys,
Roy

picture went red again after about 5 minutes of running. I zapped it again.
It shows clear when checked with an ohmmeter but goes red with retrace a few
seconds after I turn it on. It must short as it heats up. pin 8 has about
100 volts on so its not a dead short. I put 3.7 volts on heater pins to
simulate running and checked red cathode resistance, but no shorts. also
noticed inside the neck of tube is not glowing very bright when I applied
power to heaters compared to how bright it is when set is turned on. Does
heat come from the guns themselves or from a short I have in tube?
Also when I ground blue cathode...screen is solid blue.
when I ground red cathode.... no change since screen is already red.
when I ground green cathode... NO CHANGE screen still red.
Is this tube screwed completely? I get no continuity between any pins
except the heaters.
Still messing with it.
Roy

(pin 7 is screen)

 

[Asimov]

"Roy and Rosa" bravely wrote to "All" (01 Sep 05 17:31:41)
--- on the heady topic of "Re: Toshiba tube shorted. Can I clear it?"

RaR> From: "Roy and Rosa" <[email protected]>
RaR> Subject: Re: Toshiba tube shorted. Can I clear it?
RaR> Organization: Posted via Supernews, http://www.supernews.com
RaR> Xref: core-easynews sci.electronics.repair:341129