Need new green picture tube

Toshiba 36A10 36" TV is the model you have indicated---

If the screen is all red and or too bright (no green or blue can be seen) the problem is in one of two places: Either a shorted picture tube or the board that plugs onto the end of the tube.

That board sends red,green, and blue video and information to the picture tube via 3 pins on the tube (the K or cathode for each).

The set will have either 3 IC's on that board or 3 transistors, or a single larger IC for this.

to troubleshoot this:

I would locate the Red Cathode and unsolder that pin at the socket on that board--takes red out---if you have green and blue picture then---it is either the IC/transistor that feeds that on the board or the tube itself.

If it has 3 chips (usually will each have a metal plate attached for cooling) you can either remove and replace the red one OR what I do is swap it with the green or blue chip---if suddenly you now have a blue or green only screen you know that part is bad--simple as that.

If for any reason the picture tube turns out to be bad--you are finished and so is the set= way too expensive to replace it.

Let me know if you have questions or need advice.

My first concern would be that, the picture tube is going bad. The problem you describe, tell me one of the color guns is shorting. In this case I would think the green gun is shorting. There are three color guns in the neck of the picture tube. They are red, green, and blue. Most of the time the green will short as it is powered heavily in most TVs. The next thing to check, is the small board connected to the picture tube. Look for any and all bad grounds on this CRT board. This is another big problem in all Tube type TVs. On this small board there will be three color output transistors, and resistors. These will many times run very hot and will create bad grounds over time. Check and resolder as necessary. If the CRT board does not fix your problem, replace the TV. Picture tubes are very expensive and will not be feasible for replacement. Search for a new TV. Thanks for asking and show all hands of support!

i think the light u see is the standby indicator diode. take your tv to w/shop, the technician will know how to test the following
tube so called bulb using a different mother board card, and also test the mother board using a different tube ( tv bulb)
test the power supply out put 95 volts to the line tranaformer which will give you different voltages 5, 12 and so on.
the isolation methode will help us trouble shoot the problem, we should not be rigid on one part only.
okay








9

It's probably either a bad red CRT (the red projection tube) or a shorted (or open) driver transistor on the red CRT driver board. If it's the latter case (bad transistor), it can be fixed. If it's the picture tube, well, it's probably time to go shopping for a new TV.
Do you need more information? Do you want to fix it yourself? Do you have electronics knowledge and experience? If not, call a qualified electronic technician (TV repairman), and he can tell you if it's the picture tube or not.

IF (and only if) you are a competant electronic technician, CAREFULLY check and compare the voltage on the collector of the driver transistor on the 3 CRT boards. (The driver transistor is the large one, possibly connected to a heat sink.) The voltages shoud be somewhere around 140 to 160 volts. If the red one is significantly different from the green and blue ones, then it's probably the transistor. Unplug the set (and wait a bit), and check the transistor with a diode or transistor checker. If it checks bad, then you found a bad transistor. Go to NTE Electronic's website to find a replacement. If it checks OK, then you're probably looking at bad (shorted) red CRT.

no your optic block is going south u need a new light engine big bucks

You dont need a new tube. What you need is to repair the seal on your old tube and replace the CRT coolant fluid. There is a coolant chamber attached to the tube with long bolts with springs on them that contains coolant to prevent your tubes from getting hot. Yours may just need tightening, but I would replace the seal just to be safe as thecoolant can and will destroy your circuit board if its allowed to continue to leak on it.

You have a bad picture tube, or perhaps a picture tube drive problem.. To see what is bad, remove the front speaker grill under the screen in the front. Remove the screws that hold on the board that covers the front. Insidfe this set, WITH THE TV SET UNPLUGGED< Locate which one of the tubes is the blue one. Gently pull off the board from the end of the picture tube and swap it with the green tube right next to it. The green tube is always the middle tube. If the blue comes up again, then the blue tube is bad and you will most likely be better off to buy a new TV set. If the green comes up as the bright one, swap back the boards, call a tech and tell them there is a CRT driver board , or an RGB drive problem. This should not cost you an arm and a leg to get repaired. Good Luck, and let us know how you make out with the repair of this TV set.

You have a bad picture tube, or perhaps a picture tube drive problem.. To see what is bad, remove the front speaker grill under the screen in the front. Remove the screws that hold on the board that covers the front. Insidfe this set, WITH THE TV SET UNPLUGGED< Locate which one of the tubes is the blue one. Gently pull off the board from the end of the picture tube and swap it with the green tube right next to it. The green tube is always the middle tube. If the blue comes up again, then the blue tube is bad and you will most likely be better off to buy a new TV set. If the green comes up as the bright one, swap back the boards, call a tech and tell them there is a CRT driver board , or an RGB drive problem. This should not cost you an arm and a leg to get repaired. Good Luck, and let us know how you make out with the repair of this TV set.

If the picture is all green and does not shutdown then is probably not the tube and you need to check the green output transistor witch is ussually located in the crt board in the neck of the green tube,you also have an IC that gives the colors then you have a driver and finally the output,(IC and driver rarely go bad but is possible),when you pull the board out of the tube make sure it comes out easy,do not twist the board because it might brake the pins in the tube(gun) and then we will have big problems, many times they secure the board to the tube with silicone and it needs to be removed or cut before the board will come out.Each gun has an output and the defective one should be replaced with an exact replacement.Check also the conections in the green crt board.Let us know if you need more information.

you have the famous zenith shorted picture tube