Help diagnosing Motorola Quasar/WU821FS

Hello Guys,

Great forum here! I just picked up this old Motorola Quasar model # WU821FS

The audio comes through great, but the picture is nothing but snow, and occationally a black bar on the bottom warbles it's way through with a thin green line above.

I'm really a novice with old tv's(this is my first purchase, got it cheap). I'm wondering if you all could get some sort of feel of what the issue might be by taking a look at the pic w/ the set turned on.

Thanks to Dave at JustRadios, I was directed to a schematic over at Sam's. I'll be getting one of these for any future servicing needs.

It appears that the last time this television was serviced was 1982 w/ a 2 year picture tube warranty. I am the 3rd owner, but the 2nd owner received it after moving into the house (1st owner left it there), and had it stored away from the get go.

Thanks for any help!

[Chad Hauris]

I would say bad capacitors in the vertical section...check vert. output tube too if it is the tube type. make sure you follow all safety precautions on dealing with high voltage in TV's if you go in to working on it, as it can be very dangerous.

Hey Chad,

Thanks for the quick response.

This solution would be for both the lack of any reception AND the black bar issue, right?

On the back, everything pops off nicely w/ the little tabs, but the left side does not because it looks like the rear control panel has been tacked in, thus I cannot remove the back board.

I've attached a few more pics of the rear of the unit. As you can see from the rear control panel, it seems to be tacked shut.

Also, I'm curious to know what the cutout w/ the metal piece is on the lower left area?

Thanks

[Chad Hauris]

That is the lock for the drawer...this is a Works in a drawer set and you release that latch to slide the drawer out to the front. Most of the circuitry is in the drawer.

I'm trying to figure out how to release this latch? Any tips?

[holmesuser01]

Look for the FA board. If not mistaken, this has the 6CW5 vertical output tube on it, and the horizontal oscillator tube. 6CW5's can cause lots of issues.

I have not seen one of these sets in at least 20 years.

If not mistaken, you need to remove that 1/4" hex screw near the power connector before you pull the drawer out the front of the set. I can see it in your pics.

[Tony V]

Isnt there supposed to be some kind of jumper on the 75 ohm input in order to use the 300 ohm input on these? This might be the cause of the reception problem. Has the uhf been tried yet? Most of the tv's that i have had that produced snow functioned properly once proper signal was applied unless tuner was extremely dirty.
-Tony

I have it on UHF at the moment, and it only picks up audio from some strange 3ABN (3 Angels Broadcasting) channel that kind of freaked me out in a Poltergeist sort of way...hah.

[kc8adu]

iirc thats the ja board.
replace all the orange ero electrolytics
they are much more likely to be the problem than the 6cw5.
that set is a easy fix.

Originally Posted by holmesuser01

Look for the FA board. If not mistaken, this has the 6CW5 vertical output tube on it, and the horizontal oscillator tube. 6CW5's can cause lots of issues.

I have not seen one of these sets in at least 20 years.

If not mistaken, you need to remove that 1/4" hex screw near the power connector before you pull the drawer out the front of the set. I can see it in your pics.

[Chad Hauris]

Adjustments are just to compensate for small changes in picture size due to tube aging...this case looks more severe and I agree that the problem here is likely bad caps.

K, so I located these caps...They are the radial electrolytic type, correct?

There were 2 on the same board as the tubes, and one more on a board above...

2 on the tube board read:

8/50 A36 20
50/50 A29 20

The one on the board above read:

40/50 E2 A 30

I'm assume the 50 is voltage? Is the prefix uF? If so, I'm familiar with 10uF and 47uF but have never seen 8 or 50, or 40 for that matter...

Thanks

There's a simplified schematic on top of the drawer that signifies each section (this being the FA section). It doesn't say much about each part (other than tube names, and adjustment areas)....more of a map than a true schematic.

Although, by looking at this I noticed that the 3rd cap in question is not a part of the FA section that we are dealing with.

I've attached 2 pics of the 2 caps, labelled accordingly.

[holmesuser01]

Originally Posted by kc8adu

iirc thats the ja board.
replace all the orange ero electrolytics
they are much more likely to be the problem than the 6cw5.
that set is a easy fix.

Thanks, You're right. Recalling things can be fun, especially when you haven't look at a Quasar TV in about 15 years.

Alright, I hooked it up to a cable box via the 300ohm VHF set screws, and attached some pics showing the result.

Here 's a 3MB video clip of the television in action w/ the cable hooked up...

I figure this might be easier to diagnose than by mere still imagery.