Magnavox console TV/Hi-Fi

[RetroHacker]

I finally got a roundie! I had to drive all the way to Maryland to get it, but it was worth it. This console is in immaculate condition physically. This is an interesting combination - a solid state stereo tuner/amplifier, and a tube TV. Unfortunately, the TV doesn't work. The radio works, and the phono barely works. It takes a while to get up to the proper speed, and there is a lot of noise in the right channel of the phono preamp. The stereo's sound is actually not that great, it's weak and frail, with no puch or kick whatsoever, and not a lot of volume. Even with the volume and bass controls turned all the way up, it doesn't get too loud, and the bass is still weak. The previous owner replaced the output transistors in the power amp, as well as many tubes in the TV, hoping to get the TV to work. I don't know what problem the amplifier had to warrent new transistors, maybe he was trying to solve the weak sound issue too.

But, as far as the TV is concerned, it doesn't get high voltage. The flyback _looks_ immaculate - no melting, burning, or even caked on carbony crud! The chassis is very clean. I knew about the lack of HV when I got it, and the first thing I noticed was that the lead connecting the HO to the flyback cage was off (you have to remove this lead to remove/replace the flyback box). I knew that this couldn't have been the problem - he'd probably just not connected it back when he put it back together last, but I hooked it up and tried it real quick anyway. I wanted to see how well the TV tuner worked anyway. So, I hooked it up, turned it on, switched the selector over to TV, and watched as the tubes lit up. Then, there was a sharp CRACK and I saw a spark in the right side of the chassis somewhere, possibly a popping capacitor, possibly an arc, I didn't know. I shut it off. I hadn't done a soft start, since this set was powered on recently (not working, but still). I was unable to find any cause for the spark, no burnt marks, nothing. So... I don't know. I haven't done much else, I need to pull the chassis and see what else might be obvious. The set uses the orange dip type caps, but I saw a couple of those "Elemenco" ceramic caps in there, and what looked like a small cardboard electrolytic.

I'd really love to find a schematic for this set, but haven't found any identifying marks on the chassis. The chassis has the numbers 4181 stamped on it, but a search on Sam's website wasn't conclusive.

So, what does everyone think?

-Ian