Looking For Advice on Testing TX36PF10 CRT Tube

[Mike-s]

Hi Looking for some advice have a Panasonic TX36PF10 CRT television
When switched on no picture the background gets brighter and brighter then the left and right sides of picture move in towards the centre and television shuts down although audio is fine total time about 5 seconds and power led on television flashes 2 pulses every couple of seconds

Does not switch on by remote afterwards but can be switched off then on via main power switch and will follow the same procedure each time

Have included picture of screen Looking to see if it’s the CRT and a waste of time and money or a cheap repair

Have electronics experience although not on TVs my background C&G 224 control systems and HNC electronics have most test equipment except a high voltage probe looking for a service manual or some test points and expected voltages waveforms to confirm if it’s the tube

Would appreciate advice or comments

Regards Mike



[link=../../e107_files/public/1172780926_622_FT0_dscf0784.jpg][img:width=100&height=75]../../e107_files/public/1172780926_622_FT0_dscf0784_.jpg[/img][/link]

[repoman]

what voltage to you have on the cathodes on the tube base panel ?
this could be as simple as the 200 volt feed missing from the base panel.

[ExTV]

Hi
If you remove the tube base from the tube dose the set shut down?
If it dose it is unlightly to be the CRT.  Try reduceing the A1 slightly(follow the cap on the crt down to the loptx. There will be two pots one beneth the other. Top one focus bottom one A1 or screen.)

[Mike123]

Hi
Many thanks for replies obtained a service manual for the TV which helps looking at the y panel can you tell me  the cathode voltage is it  just checking a 200v supply on the y3 connector  to the board pin 4 and ground  or is it a pin out on the tube base connector  

tried to log in with ould ID but my mind is like the tv at the moment US

[Mike123]

Can anyone tell me what the  equivalent to this transistor is please  2SA1535ARLB

[Mike123]

[quote1187775162=ExTV]
Hi
If you remove the tube base from the tube dose the set shut down?
If it dose it is unlightly to be the CRT.  Try reduceing the A1 slightly(follow the cap on the crt down to the loptx. There will be two pots one beneth the other. Top one focus bottom one A1 or screen.)
[/quote1187775162]

Hi many thanks for your reply sorry for delay in replying removed the tube base and the problem of the TV shutting down has stopped  guess this is not a good sign?  Found the Loptx but it has 3 adjustments which one is A1 please



[link=../../e107_files/public/1187777232_1547_FT205_loptx.jpg][img:width=100&height=75]../../e107_files/public/1187777232_1547_FT205_loptx_.jpg[/img][/link]

[Mike123]

[quote1187782223=repoman]
what voltage to you have on the cathodes on the tube base panel ?
this could be as simple as the 200 volt feed missing from the base panel.
[/quote1187782223]

It’s listed as 200v in the service manual but starts at 239 and rises to 257 when the TV shuts down

[P.R.Gore]

I wonder if your problem is yet solved or not. If not then try this-1>Open H.Out. transistor & check +B voltage. If it is excess, fault is in power supply. 2>If +B is normal then replace flyback capacitor. In both cases X ray protection circuit activates & set enters stand by mode. 3> If both are ok then X ray protection circuit itself cold be faulty, try replacing its discrete  components.