1984 RCA FJR2010T - Light Dependent Resistor

[BlackRX]

Hello all,

I recently rescued this RCA Colortrak 2000 off the side of the road. It's in pretty good shape!

The only issue I have with it is the light sensor along the top of the set. If I don't blast the sensor with the light of a thousand suns, things look pretty dull, but not completely unenjoyable. It only impacts picture/contrast.

With that being said, has anyone had experience with working around that thing? I'm not opposed to going in and jumping that sucker out, but how much disassembly is required?

Thanks in advance for any insight!

[old_tv_nut]

Check if turning off any automatic color setting also disables the light sensor.

[BlackRX]

Originally Posted by old_tv_nut

Check if turning off any automatic color setting also disables the light sensor.

No automatic settings to be found. No on-screen menu either.

[zeno]

Ditto Old Nut.

I never had one fail. This is a great set. Lost a lot of sales on them til Zenith came out with a cube. They were famous for cold joints in the tuner / micro boards. See if it routs through them.
BTW IIRC to go into video you need to press "91" or something like that.
Maybe JohnCT will pipe in. He knows RCA well.

Zeno

Originally Posted by old_tv_nut

Check if turning off any automatic color setting also disables the light sensor.

[JohnCT]

Originally Posted by BlackRX

Hello all,


The only issue I have with it is the light sensor along the top of the set. If I don't blast the sensor with the light of a thousand suns, things look pretty dull, but not completely unenjoyable. It only impacts picture/contrast.

In the back of my skull I remember a contrast "preset" trimmer on the board. It was green IIRC - it used a hex tip tool to adjust or you could probably just turn it with your fingertips.

If the layout label is still inside, get a bright flashlight and a magnifying glass (or take a pic of it and blow it up) and see if there's a contrast preset trimmer somewhere in the center of the board.

[BlackRX]

Originally Posted by JohnCT

In the back of my skull I remember a contrast "preset" trimmer on the board. It was green IIRC - it used a hex tip tool to adjust or you could probably just turn it with your fingertips.

If the layout label is still inside, get a bright flashlight and a magnifying glass (or take a pic of it and blow it up) and see if there's a contrast preset trimmer somewhere in the center of the board.

Haven't popped off the back cover yet, but I have visually confirmed the existence of this preset control (it is labeled "cont. preset" on the board). Good looking out!

Now that we know there's something that can be adjusted, how would you suggest I go about this? Better safe than sorry.

[damen]

I regularly used to jumper those things out because of customer complaints. If you can see the two red wires connected to it from the back, just cut them off and twist the bare ends together. If they're not visible, the plastic front mask of the set can be tilted out forward enough to access it. Requires one of those long quarter inch nut drivers.

[Blast]

If you're going all the way into the back of that cabinet to get to the control panel watch out for the anode cap on the CRT. Ask me why I mention it...

[BlackRX]

I'm definitely not trying to have a barbeque with this thing.

With that being said, would leaving it unplugged for like 72 hours be enough to make things kind of safe?

[BlackRX]

Originally Posted by damen

I regularly used to jumper those things out because of customer complaints. If you can see the two red wires connected to it from the back, just cut them off and twist the bare ends together. If they're not visible, the plastic front mask of the set can be tilted out forward enough to access it. Requires one of those long quarter inch nut drivers.

I found the courage to go in tonight. Success. All it took was some snipping, stripping, and electrical tape. Thanks!

Images for anyone interested:

Two wires on the upper left side.

The resistor being wired to this connector minimized the amount of time my hands spent in there.

Here's a before and after comparison.

[Electronic M]

Originally Posted by BlackRX

I'm definitely not trying to have a barbeque with this thing.

With that being said, would leaving it unplugged for like 72 hours be enough to make things kind of safe?

From someone who has lost count of the CRT HV bites he's gotten.... It's basically the same as the meanest static jolt you get from shuffling on carpet and grabbing a doorknob.... Infact carpet can be higher voltage and is about the same amount of charge as the cap in a CRT stores...
If you want to barbecue yourself get a fully vacuum tube set and grab the plate cap of the horizontal output tube while running...The RF burn you get will remove skin and add char...Ask me how I know.