Advice sought for 1968 RCA GL-644W

[Radiophile2001]

Originally Posted by roundscreen

Best I can tell ya is get one that looks like this one with the crooked arrow pointing at it. {see picture}. Look around your parts chassis and you may find one that is in good shape.
Late 60,s color sets are cool.

Thanks.....found one that looks just like that at an online store, but don't seem to notice the "side mounts" on this pic you show. Would the side mounts make any difference at all in installing the socket? Is it just that I can't see the side mounts on the pic shown?

Was kinda hoping not to have to move the RCA set to see for myself until I'm good and ready for "the project" (but may have to).....a bit tight with sets now in this room....!

[roundscreen]

Originally Posted by Radiophile2001

Thanks.....found one that looks just like that at an online store, but don't seem to notice the "side mounts" on this pic you show. Would the side mounts make any difference at all in installing the socket? Is it just that I can't see the side mounts on the pic shown?

Was kinda hoping not to have to move the RCA set to see for myself until I'm good and ready for "the project" (but may have to).....a bit tight with sets now in this room....!

Here is a side view of the socket. Hopes this helps.

[Radiophile2001]

Great, thanks again!!

[Radiophile2001]

Ok,

Replaced the tube socket a few weeks ago, and did a darn good job on it!

However, it only brightened up the raster/screen a bit. Not sure if the PC board has a cracked connection path, or what it could be now.

Still no sound, static or TV stations. Just white screen. I can make it shudder by out-adjusting the vertical knob.

So, I'm looking for recommendations on repair shops in the DC-Northern VA area.....or individuals....who might be able to fix this set. Looking for some way to get it done "cheaply" and am in no huge rush to make it happen.
I know most shops would easily charge $500 just as a deposit.

Thanks!

[drh4683]

If youd like to really get into TV troubleshooting, this set is a great way to start. First thing that needs to be done is isolate the tuner from the chassis. You can go on ebay and see if you can find a tuner subber. Simply connect the output of the tuner subber to the video IF cable of the TV set (the large black co-axial lead thats connected ontop of the TV tuner). If the tuner is defective, you should have a picture displayed on the screen. if not, the problem is withing the chassis.

According to the descriptions, you have an IF problem.

Whats the status on the 6DS4 rf amp (on the tuner)? Its a nuvistor, a small metal cased tube.

By chance do you have a tube tester? If you have a VTVM we can really get into troubleshooting. If you dont have either and would like to seriously get into servicing these old sets, you can get great deals on ebay. I have an RCA WV-98C voltohmyst VTVM and a sencore TC-162 tube checker. These are my heavily used instruments. You need a VTVM as it has high input impeadance (11 meg on my RCA with its DC probe in place). Some digital mulit meters have high input impeadance too (about 10 meg) and are OK. This can be enjoyable and educational if its something youd like to do. Nobody in the TV business wants to work on these sets anymore and will give you a high estimate to scare you off. ITs because of that or its another way of them telling you "we dont know how to fix it" and give you the sky high price.

[Radiophile2001]

Doug,

I agree with you.......probably the only people in the world that know how to fix these sets (with confidence) are present in AK. It would be tough to find a shop to do it reasonably or at all.

Now as to the gear, I have nothing but soldering irons and solder. Don't know how to read a schematic.

It's got to be the chassis....the tuner was fine all along and it all seemed to center around that one HO 12HG7 tube. That's where, for a while, I could get the set to work fine if I moved that tube just right.
However, I do also remember there was a brief period of about a half day (just as it started its downhill trend) I would change VHF channels and the screen would go totally black between channels--like instantaneously and briefly as I was turning the knob.

Both the old and new 12HG7 tubes I have light up, but no luck beyond that.
I had soldered the ground connections on the chassis back a while too....not sure if that helped or hurt.

Would love to just pull the chassis and ship it to you.... (But not via Craters & Freighters this time!)

[Chad Hauris]

Do you have the schematic? I can find a copy to post here if you don't have it.
What you need to do is check voltage test points and compare them to what is on the schematic, starting with the power supply.
It's pretty easy with a digital multimeter and we can help you with reading the schematic.
I really think it is no 80 volt supply to the transistorized IF stage, this has happened to me on a CTC-39.

[Radiophile2001]

No, don't have the schematic.....maybe I can check on EBay or Sam's. If that's what's wrong, what might be the top causes? Does that include a cracked PC board? Because I know it has cracked, just can't see any broken paths.

thx