1984 Panasonic PC-26L01

[Jon A.]

Set is long gone.

[Dreamsbeard]

That's a nice panasonic! It has this early 80's look I like very much. That control panel looks a lot like the Quasar.

[Jon A.]

Yeah, I saw a pic of an '80 model with the same panel. I was hoping the CRT wasn't weak, but I jacked the color level and got smearing, so I'll be awaiting a console with an ugly cabinet but a good CRT. I like it enough to not just part it out. Sucks that my 25VCXP22 won't work in it. I'd still like to know what that odd noise is though so I can get that sorted out when the time comes.

[zeno]

To track down noises.
Unplug speaker to be sure its not from there.
Use an old paper towel tube as a stethoscope.
When you get to the area use a plastic tool to lightly probe
around & look for the noise to stop or change. Almost always comes
from the FBT, small transformer or choke or the yoke.
Ticking & buzzing comes from power supply or vert.
High freq noises from horz, pin, HV or switching power supply.
Some sets are noisy by nature.

Dont know why the arc on turn off. Just be sure the dag & CRT
board are well grounded to the main chassis.

BTW will look up that Zenith tomorrow.

73 Zeno

[Jon A.]

Muchas gracias. I thought of using a towel tube earlier, don't want to get my head too close to anything in there especially when it's running. It's not like I'm trying to hear a train coming and I sure don't want to end up feeling like I've been hit by one, heh.

[Jon A.]

Got at it with a tubeoscope, the sound is most audible at the CRT neck. Forgot to check the yoke for the noise source. Also, I do get a lot of flickering on the screen. This thing was sitting in a damp environment for a while, a shield in there has some surface rust. I decided to re-seat the yoke plug to see if the noise would go away; it didn't, but no more arc on power-off.

Edit: Finally checked the yoke; yep, definitely the source of the noise. Kind of a rattling with the occasional snap.

[rca2000]

WHile not normal--"yoke rattle" is a problem many of us here have seen many times. I happens when some particles in the yoke begin to loosen a bit and "rattle" at some harmonic, usually o0f the vertical frequency. That is what you hear. While annoying, it does not always mean the yoke is dying--though you MAY see a bit of jittter in the pix--coinciding with that rattle..

[Jon A.]

The light snapping noise is occasional once it warms up, but when it's first started it snaps quite a bit. The rattling on the other hand is constant. I'm concerned that the yoke will eventually dead-short and take out something else.

BTW zeno, what's "pin" shorthand for?

[zeno]

Pin = pincushion

NAP had a lot of trouble with rattling ( vert ) yokes must of been
early to mid 90's sets, L chassis IIRC. We used to spray
them with something but cant remember what from the hardware
store. Takes 2-4 coats but it silenced them. That was via NAP TA.

OH BTW no Zenith manual.

73 Zeno

[Jon A.]

Scratch that, I don't consider this one worth a CRT and yoke swap. The cabinet makes a nice stand for my near-mint 1978 XL-100 that I believe was sidelined early in its life due to a common vertical failure. Got a transistor sub on order for that.