Trying to fix an old CRT TV, and i have a fairly simple question

So guys im trying to fix an old CRT, the tv is not actualy dead it just has a problem in the vertical circuit. Using the Repair service manual i found the exact same problem i have.



Now i uploaded an image and the red circle is the problem i have, that picture is pointing at what to me appears to be an resistor, now my question is really simple, is that a 1kohm resistor ilustrated on the picture?

Hope you guys can help me.

Thank you in advance.

 

1k potentiometer

 

Also worth mentioning that if you have full service documentation it will tell you the exact type and value in the parts list. It should tell you if it is a safety critical component ie. fusible resistor, and therefore should only be replaced with the manufacturers' recommendation.

 

thx calpis that even made it more easy to find, il just had to test each potenciometer, and i found it very quickly thx again.

old gaming fart, after i found the potenciometer i saw that the repair manual i had it wasnt the exact model of mine so i cant actualy follow it when i comes to parts lists. and i cant find any info on my tv so its gonna be very dificult to find the correct replacment

 

With potentiometer's it'll be ok to replace it with the same type, it's only the standard resistors you have to be a bit more careful with. Apologies I wasn't clearer in my initial post.

 

generally speaking old crt tv had a lot of failing capacitors, try replacing those that are in a hot temperature area, do not mess with the pots until you can check that everyting else is working fine you may end up with a bunch of new troubles, if the problem is vertical deflection start replacing vertical deflection capacitors, since deflection is just a pulse of some voltage, try changing the power supply caps

 

pc_91 thx for the advice, and i have new info, so i got a potenciometer and started by replacing the bad potenciometer i found (BTW on the back of the board there was a similar image that i posted above with the tv screen and it was pointing to the exact potenciometer i was going to replace, who needs service manuals) so i replaced the potenciometer, and gess what, its not the potenciometer, as soon i replaced it i was checking the the OHMS and i was getting the exact same values of the old one, and the tv had the same problem, so for some reason the potenciometer is not working in that particular area, i dont know why do you guys have any ideia?

Also pc_91 getting capacitors where i live is not easy there arent any hardware stores arround my area to buy such things and most of my repairs are beeing done from scavaging parts from broken electronics, and im not an expert on electronics i only have some basic know how and basic expirience, so replacing all the caps would cause more harm than good,so is there anyway to test if a capacitor is good or not?

EDIT: I made a small video about the problem.

http://youtu.be/e0oDyj8JCeg

 

i looked at your video, those pots look bad but they don't tend to fail, is usually a issue with capacitors, just to try, mess with the pot marked with the draw of the failure, thats the vertical size pot, if it doesn't make any change it maybe failing the ic that generates the pulse for vertical, about getting components, scrap is a really useful place to find them, another tv, not so old but not so newer is a good supply of components, newer tv are too cheap, and older ones are maybe worse than yours, for replacion capacitors, in such devices is a pretty much forward thing, as you don't put a capacitor with lower values than the original, and don't put it backwards is going to work, since only are there to filter the supply, in some tv's, capacitors were used to limit the vertical and horizontal size, also noted than your pictures is towards the lower part of the screen, i've see plenty of those failures, most of the time were capacitors, besides that, you've got a great tv, mi family used to own a little bit newer philips, i almost cryed the day they sold it, awesome colors had those tv. good luck! in case you want to talk me directly pm me and we contact for another medium idk, gtalk or facebook or whateve

 

The service manual for this TV is available for free download >here< - looks like it is using the CTX chassis.

You should probably re-fit the original potentiometer or replace with a new 100 Ohm one. Try an out-of-circuit test on it first using a multimeter. It will show 100 Ohm resistance on its minimum setting.

If you imagine the potentiometer like a triangle shape, you should measure from the pin at the top of the "triangle" and then only one of the pins on the base of the triangle. Depending on which way the potentiometer (or pot) is turned, it will decrease the resistance towards the pin or increase it when turned away from it.
If you get no resistance reading at all on your meter then the potentiometer is broken or 'open circuit'.

Looking at the diagram for the vertical section, you should start by verifying your potentiometer works, then set it to the maximum picture height. If the picture is still squashed, start by replacing the following electrolytic capacitors with 105 degree type, preferably 'Panasonic FC series' or other good quality brand (Nichicon, Rubycon, Elna) 105 degree types:

47uf/ 25v at location 2505
0.47uf/ 63v at location 2506 (can use a more common 100v type).
22uf/ 50v at location 2401
40uf/ 6.3v at location 2330 (can use a more common 10v type).
100uf/ 40v at location 2600 (can use a more common 50v type).

...replace more in this area for continued reliability, and re-solder any dry solder joints (use a magnifying glass and strong light source, and look for >these<).

Always observe the correct polarity on the capacitors. The negative (-) side always has a black or coloured stripe down one side of the capacitor body. Always mark the negative side on the PCB with a marker pen before replacement. Do not trust the PCB markings as they are sometimes incorrect.

Always verify the voltage of the capacitor is within tolerance (e.g. do not replace a 50v capacitor with a 25v one). It's usually OK to be over, e.g. replacing a 25v capacitor with a 50v one is fine.

If you find you are still having problems, replace the vertical IC which is marked TDA3651AQ. There's one for sale >here<

 

ok guys right now its late so tomorow i will try and make a few more tests, now i need to get courage to discharge the high voltage connection, because im actualy very afraid of doing that, and thats the main reason why i use latex gloves to work on the tv, i could leave it on but that makes it very dificult to work on the board as i have a very limited space. anyway is there an easier way to do this can i remove the wires directly from the flyback transformer? because i watched some videos and the connection on the CRT seems to be very tight and i dont wanna risk fucking anything up.

 

It's wise to be cautious, these older TV's without SCART inputs often have a totally live chassis, which means that the whole circuit board is potentially live when in use. I don't recommend carrying out adjustments with the TV plugged in and powered on.

Discharging the CRT is relatively straight-forward. I think the service manual has a few notes about it to guide you. You can normally discharge directly onto the earthing straps around the back of the tube, but be careful not to accidentally zap the mainboard!

The plug itself just requires some sidewards pressure, and then a small tug. It should come off with relative ease, although it's best not to force it or rotate it too much. Normally what I do is push downwards on it to help free one of the clips, and then pull to release it.

I don't recommend trying to release the cable from the actual flyback, as a). you're more likely to get zapped by any residual charge (or zap the mainboard) and b). the seals around the flyback may end up damaged (and the cable might not be removable anyway).

 

totally agree, be careful if it's live chassis, an easy test to know is to put the multimeter on voltimeter, grab one probe and with the other touch the chassis be careful not to touch the cassis while doing this, about discharging the HV is pretty much straight forward, do not try to remove the wire from the flyback, you will end up zapped really bad and with a destroyed flyback

 

i belive its a live chassis beccause the wire that comes from the HV to the flyback, passes by this huge metal plate, i took a picture of the wire passing by the metal plate.



The wire looks like its "discarted" (sorry i couldnt remeber the right word)

 

Yes it looks like that's part of the internal grounding arrangement. It's there to prevent static build-up or any leaking high voltage from zapping sensitive electronics.