NAP PTV300 Chassis Interchange?

The new type flyback is more reliable than that old chunk it replaces. As for there being any potential problems in the future? Well, it's a PTV300. You've been playing on bonus time for many years now.

You won't need new seals when you change the coolant. Just get the coolant changed before the replacement boards crap out.....

John

It's unusual to find one of those relics that still works. We used to call them "gourmet flybacks from Orville Reddenbacher", you know - not a one left unpopped ;-) A slight exaggeration, no doubt, but a *lot* of them blew up. I guess if you have one that survived this long, no reason not to keep using it.

Another common problem about that vintage was green circuit boards that used square pins shoved through the board for feed-throughs instead of plated-through holes. This attempt at cost cutting was a notorious source of intermittant connections. Some were so bad that they required repair right out of the box before they could even be sold.

Aside from the questionable reliability of certain parts already mentioned, I don't see a problem. There were minor variations for special versions like the JBL sound system, but basically they were intended to be compatible. As you have discovered, the HV lead is different, so just use the one that came with it.

Fair chance. We used to carry a set of spare boards in the service truck for elusive problems. Sometimes easier to swap in the home and rebuild back at the shop where presumably you have better lighting, more tools, parts, and equipment.

The O-rings between the lens and the cooling chamber are quite durable and usually reusable. I have not often needed the gasket between the CRT and cooling chamber except on the rare occasion of replacing a tube. Philips didn't list these parts separately in the manuals, but shows one each as parts of the 171677-3 kit. I used to have the individual numbers written down somewhere but can't find them anymore.

set

splitter, I

Unfortunately, the dead flyback is one of the angle HV connector types. Found a sticker in the bottom of the set: 3620030005. Have found similar ones for 3620030006/7. The newer board had the 352140-1 flyback on it. Guess I can just repair it if (when) it blows.

Yep, the convergence board required resoldering of these square pins. Had a blue ghost that would appear and disappear when the set warmed up. The old p/s board is green with those nasty square pins. I reflowed some fresh on the convergence board and that took care of the problem.

Would it help to replace the electrolytic caps on the deflection and power supply boards?

What sort of sealer/lubricant should I use on the o-rings? Or, should I just clean out the crud the best I can, replace the coolant (with the set angled so the crt in question is level) and see what sort of improvement I get?

Thanks again for the advice. The cabinet on this thing is so nice that I'm having a hard time getting rid of it.

Kirk S.

Sorry I misunderstood your message, I thought you were saying you had one of the angled type still working.

They didn't seem to be a big problem on these boards. If you have an ESR checker, you could test them while the board is out. Or if they have leaked or gotten hot.

They don't use any sealer. Be sure to clean the groove and "C" element surface squeaky clean. The glycol solution cooling fluid is plenty slippery.

You'll probably see what is going on as you disassemble the things. The lens assemblies can be removed anytime (four 1/4" screws), but you will want to suck or drain most of the fluid before removing the "C" element (larger nuts), or you will make a big mess. Once the "C" element is out, you can clean the inside of the chamber with toilet tissue, paper towels, etc. For stubborn encrustation, you can use alcohol, windex, etc. Finish up with something lint free.

Once you have things clean you can remount the "C" element and fill the tube. You will need to have the tube angled like normal operating position if you left it in the set, or on its side if you pulled it. With the tube level you will not be able to get enough of the air bubble out of it.

Do the blue tube first, it's always the worst and will give you the most noticeable improvement. The green and red will then seem easy.

similar

Well, it "was" working until it died. Been reading about "ringing" a flyback using an o-scope and the calibration setting. Looks like a good chance to practice on a bad one.

power

None look like they are leaking/bulging so I won't break it by fixing them...

Great... Sounds like I can do it in the set. I'll get an idea how much is in the chamber when I suck it out. Got two 24oz bottles from MCM. Hope it's enough...

I'll follow your instructions about convergence, screen, cutoff, etc...

I'm sure that I'll be back for more brainpicking. Learning about this stuff is very interesting.