RCA pincushion woes continue.

RCA model P46725SK, chassis on back says PTK169PFA, but on chassis inside cabinet says CTC169PF. Original problem was cracked focus/screen block (though I see that someone has replaced the HV splitter block as well before I got my hands on it.) I posted earlier regarding the missing little board on the HV splitter block, but have since learned that apparently they didn't all have that little board - this is the first one I've seen that didn't.

The remaining problem is the pincushion. This chassis has a pincushion board off of the main chassis that I have checked the components on several times (all tested OK) and even replaced Q4850 on it since I read one post where someone had it test good when it was in fact bad. The picture is very good except for a classic pincushion (actually bowed out at top and bottom) and none of the controls have any effect on it. I keep reading about CR4402, C4401 and C4402, but I don't see them on the board anywhere (though I'm certain that they're there and probably marked differently) and all the components around the HOT that I suspected may have been them seem OK. Can you get that pincushion board as an entire assembly somewhere? Is the consensus that the pin board is the problem?

Thanks in advance for any ideas/previous experiences with this.

Kevin

RCA model P46725SK, chassis on back says PTK169PFA, but on chassis inside cabinet says CTC169PF. Original problem was cracked focus/screen block (though I see that someone has replaced the HV splitter block as well before I got my hands on it.) I posted earlier regarding the missing little board on the HV splitter block, but have since learned that apparently they didn't all have that little board - this is the first one I've seen that didn't.

The remaining problem is the pincushion. This chassis has a pincushion board off of the main chassis that I have checked the components on several times (all tested OK) and even replaced Q4850 on it since I read one post where someone had it test good when it was in fact bad. The picture is very good except for a classic pincushion (actually bowed out at top and bottom) and none of the controls have any effect on it. I keep reading about CR4402, C4401 and C4402, but I don't see them on the board anywhere (though I'm certain that they're there and probably marked differently) and all the components around the HOT that I suspected may have been them seem OK. Can you get that pincushion board as an entire assembly somewhere? Is the consensus that the pin board is the problem?

Thanks in advance for any ideas/previous experiences with this.

Kevin

Kevin,

The pincushion is visible viewed at the chassis very close to the horizontal transistor heatsink on right. Fat diode with one ferrite bead and a capacitor in parallel with this diode. This is the set for pincushion.

C4402 is cap, CR4402 is diode with the ferrite bead, they're marked on the chassis as C4402 and CR4402. You will see cap sides swelled and diode shorted, measure that diode. Replace both. Sometimes need to replace small transistor.

Cheers, Wizard

Hi Wizard,

I suspected those were the ones - they're marked c402 and cr402 on my board so I wasn't 100% sure. That diode checked good but I tried a different diode with similar characteristics in it to see if it made a difference at all, but it didn't. I don't have any box caps like that - I'll have to order some and replace all those suckers. I was surprised they weren't electrolytics... Much thanks for your help!

Kevin