Panasonic CT-1310M keeps blowing horizontal output transistor

[ARC Tech-109]

The capacitors that are involved in the power supply itself, replacing the caps in the video circuit have nothing to do with the power supply itself. Those would be the likes of C558, C805, C502, C307, C203, C564, C1603 & 1604 for starters.
I know that flux smells bad, been burning that stuff since the late 70's myself so I know where you're coming from but when you described having to hit the set and things started working that was the first clue to intermittent connections. The gradual shift to bright then loss of H-sync points to either a thermal issue that might be taking down a power supply line or a bad capacitor that's hogging current. You found that bad one over in the horizontal and while the 80's didn't have the "capacitorgate" they're still prone to failure due to their wet internal construction. Just the nature of them.
If the smell of the flux is that offensive it can be washed off using either acetone or isopropyl alcohol however the main board should be removed as these will damage the cabinet plastics.

Learning electronics isn't easy, after 45 years I'm still learning and getting off the ground can be really tough when you're dealing with a tough dog. Test equipment is essential but sometimes the best tool is the experienced gained over the years, best advice I can offer is to take it slow, read & study the schematics and stick with it. I started swapping tubes in old B&W sets when I was in the 3rd grade when Carter was in office. You will get there, problems are only opportunities in work clothes that are designed to bring you up to the next level. You CAN do it.

[luRaichu]

Originally Posted by ARC Tech-109

when you described having to hit the set and things started working that was the first clue to intermittent connections. The gradual shift to bright then loss of H-sync points to either a thermal issue that might be taking down a power supply line or a bad capacitor that's hogging current.

I think it may also be an issue of the tube drawing TOO much current. Because the picture looks brighter post-recap. Almost too bright. It actually gets less focused.
That's why I alluded to the Sub Bright pot. Perhaps we can see if running dimmer will stop the horizontal f*ckery. Then we will know if it's an undercurrent or overvoltage problem.
I'm tempted to think it is overvoltage, like zeno said.

Originally Posted by ARC Tech-109

Learning electronics isn't easy, after 45 years I'm still learning and getting off the ground can be really tough when you're dealing with a tough dog. Test equipment is essential but sometimes the best tool is the experienced gained over the years, best advice I can offer is to take it slow, read & study the schematics and stick with it. I started swapping tubes in old B&W sets when I was in the 3rd grade when Carter was in office. You will get there, problems are only opportunities in work clothes that are designed to bring you up to the next level. You CAN do it.

Thanks for the pep talk, although slightly unnecessary. I know I'll get the set in tip-top shape eventually.
My last and first recap was a Macintosh LC. The logic board required surface mount caps while the rottening power supply used through-holes.

[vol.2]

Originally Posted by luRaichu

I think it may also be an issue of the tube drawing TOO much current. Because the picture looks brighter post-recap. Almost too bright. It actually gets less focused.

It will look less focused when the brightness and contrast is higher, that's normal. definitely turn it down to something that looks "normal" if it's gotten brighter after replacing caps.

I agree with the other post about the supply caps. Pull and test any electrolytics in the supply. That's 802 803 804 805 in the 130 V, 502 in the 12V, and all those other small voltages, C558 C203 C307 C564 C1603 C1604

Pay special attention to the caps shaded in grey

If you don't have an LCR meter, you can buy one of these cheapo component testers off ebay or amazon (any of them are the same not just this link)

It's not going to be super accurate, and it can't go up super high in capacitance, but it will at least give you a go-no-go reference for telling if a cap is super high ESR or open or shorted in some way

Also you might want to test the supply transistors. Q801, Q802, Q552 You can either test each leg just to confirm they are functioning as transistors still, but those cheapo component testers will quickly tell you if they are probably still working or not as well

[luRaichu]

Originally Posted by vol.2

Pull and test any electrolytics in the supply. That's 802 803 804 805 in the 130 V, 502 in the 12V, and all those other small voltages, C558 C203 C307 C564 C1603 C1604

I replaced all of those except C1603 or C1604 since they were on the channel selector board. Best to do that while we're at it.