CRT Console TV Repair

[zander21510]

Forgive me if this isn't the right place to post this...been searching around for a while trying to find some help on this.

 

I'm currently trying to restore an old RCA console television to use with my retro game consoles. My uncle found it for me in excellent cosmetic condition, and was apparently used up until a few years ago, taken care of in an old woman's house till she passed away. Sticker on the back says manufactured in 1986, it's a RCA Colortrak 2000- very high end for the day.

So the problem it's having, from the research I've done, seems to be consistent with some bad capacitors. There are some lines on the top of the screen, and it will lose power randomly before coming back on. I would say it works fine 60% of the time, the other 40% the screen goes out for a few minutes, and comes back on intermittently.

I'm fairly comfortable with soldering & I want to try to replace the capacitors, problem is, there are SO MANY and I'm not sure where to start. From my research, I should be looking for bulged or leaking capacitors, but I haven't found any except for just one that seems like it's slightly bulged on the top.

The nice thing about this TV though, is it has a bunch of reference stickers on the inside of the cabinet, that look like diagrams. Over my head for sure, but hopefully someone can make something out of it?

I've attached pictures of the main board inside the cabinet, along with the reference stickers on the side, and circled the one capacitor that seems bulged. If someone could help me pick out a few capacitors to start with to replace, it would help me not pick ones that won't make a difference and reduce the possibility of me messing something up. Let me know if you need more/better pictures or want to see the other boards. Thanks!

 

 

Full cabinet:

 

Main board (capacitor that's slightly bulged is circled):

 

Main board diagram:

 

 

[+Stephen Moss]

You might be better off taking it to someone who knows how to repair CRT monitors/TV sets.

However, if you do want to try and repair it yourself I would change that capacitor, also if you look just below and to the left of that there are three black cylindrical diodes then look a little crispy to me, and it may just be solder flux but the PCB looks a little burned between two of them so I would also change those (in lieu of a better photo to confirm their crispyness). Additionally if you look to the right of that capacitor you will see a blue disc shaped object (probably a capacitor but could be an inductor) the case of which also appears damaged so it might be with also changing that.

However their damage my be symptomatic of a problem(s) elsewhere in which case either the replacement will fail again fairly quickly of something else will be damaged in their stead, but that is the risk you take when replacing parts without finding the root cause of their failure.

 

As for the diagram, the top section shows where all the components are located on the main PCB and in some cases also what their adjustment affects, the mid section lists all the test points on the PCB and what voltages/signals should be found there (so you could check some of the supply voltages are correct but be careful, some set have live chassis so do not touch any metal parts with the set on).

The bottom section indicates what the parts do and their part number, unfortunately the part numbers given refer to an internal parts list rather than the components value or manufactures part number which does not make it easy to find an exact replacement if any identifying lettering has been burnt away.

[+-^CrossBow^-]

I'm quite amazed at how clean all of that looks to be honest?! For being 30 years old, the electronics are in very clean shape?! But when it comes to replacing the caps on CRTs... there are two camps to this thought:

 

1. Get a meter that can read the cap values properly while in circuit and just replace what is out of spec or bad.

 

2. Replace all the caps.

 

I'm more of in between on this camp and feel that all the caps should be replaced at least on the main chassis board. But as you stated there are BUNCH on that set. Some of them, the values can easily be read, but some of the others will require having to remove stuff to see them.

 

Have you looked online to see if perchance, someone already offers a capacitor replacement kit of this model or similar model RCA tube TV?

Edited January 30, 2017 by -^Cro§Bow^-

[mojoatomic]

I worked on similar models. Your first issue is in the power supply, caps are leaky and need replacement. Second is heat scoring on those diodes. They're allowing a lot of ripple and reverse current and smoking the caps, which was more than likely the root cause of initial failure. Wavy lines? Horizontal or RF ripple bleed. Horizontal is separate from vertical flyback (high voltage) - if you have deflection, your HV flyback is OK. There will also be some high voltage rated mylar caps shortly after rectification - guarantee you they are bleeding and allowing ripple through.

 

That "click" you hear when it powers off is called a "crowbar". It's a zener referencing ground kicking in a protection circuit and powering the set off. It's happening because of the failed parts I mentioned above. It will get worse and click all the time, like once every second. You will hear HV spin up and down, and then even that will stop working eventually.

 

That's a 50KV tube, minimum - don't let it knock your balls off. They charge up to around 15-20kv just sitting in daylight (phosphor charging), and when you get across it - you will know it. They are basically huge fast discharge glass capacitors.

 

Don't touch the HV side... but if you MUST - then before you work on the HV side... you need to discharge the tube, and DON'T solder the flyback or surrounding areas with it connected to the anode. Unplug the set. Take a well insulated screwdriver, clip a solid connection to earth ground. Stick it under the anode nipple and listen for the "pop" and arc as it discharges to ground. It's not subtle, your gonna hear it. Push the spring clip inside the anode to allow you to remove it from the tube. Leave your grounded screwdriver hanging in the hole for the tube so it won't charge up. Don't even think about plugging up the set in this state.

 

These TV's had brilliant pictures, luminance, color separation and brightness, truly great. They achieved that in no small part by using massive flyback voltages.

 

Don't put both hands inside the set while it's powered up, or unplugged... keep one hand in your pocket. Make sure the set is more grounded than you are.

 

What I'm really telling you is... this isn't a toaster. Take it from a guy who repaired these for many many years. It's easy to get hurt, bad and quickly.

Edited January 30, 2017 by mojoatomic

[crtfreak]

If your not a member you might want to join The CRT Collective on facebook. Tones of very knowledgeable CRT collectors/modders on that site and they may know someone near you that repairs tv's.

 

Would love to see a picture of the set from the front. If you cant tell by my name I have at thing for CRT's

Edited January 30, 2017 by crtfreak

[zander21510]

Thanks for the replies! @crtfreak I'll check out that facebook group, maybe they can help me with my even-older '68 vacuum tube GE Portacolor as well .

 

I did notice that on the underside of the main board, there was that same crusty yellow burnt looking stuff, probably under those diodes you mentioned @Stephen

 

I leave the set unplugged most of the time...during Christmas I had it behind a Christmas village so didn't get to work on it or use it...so it's been without power since December. I've worked with plenty of modern electronics so I know the do's and don'ts of grounding & electricity, figured that after a month or two it doesn't have a charge. I've read online though as long as you unplug it, letting it sit overnight will be long enough to discharge all the caps & tube, or should I still be cautious?

 

I think I'll take some more pictures, check out that FB group...and power up the set to give you guys a better idea of those lines I'm talking about. Maybe I'll set up my tripod to record the TV when it goes out (it usually does given enough time).

[mojoatomic]

Well, the issue is that the tube will charge without even being plugged in at all. Just light hitting the phosphor in the tube will charge it, way more than what most are prepared for.

 

As long as you don't get near the HV side, it shouldn't be an issue. My advice is to work from the plug through rectification, ripple & step down. All of that has to be right before you go any further anyway. Rectification looks to be an issue, and it probably caused the ripple issues that caused the failure in the caps (combined with their age). Make your Wheatstone bridge with diodes rated higher than are in there now... 600v, 1000v if you want, as it won't hurt anything. Every electrolytic in the primary power supply is failing by now in any case. Up shot is that they're not expensive, nor are they hard to replace. Should be a pair of 470uf (or close to it) and some 2200uf - they'll all be about ready to pop. Don't worry if they're domed or not - just look at the diodes feeding them - they're gone. Should see some large Mylar ones as well - I'd replace those for sure. As caps are much smaller than they were in '86, you can put overrated ones in there that will occupy the same or less space than the originals. Any voltage rating is fine, as long as it's the same or more than what was originally in there.

 

If you cherry pick the electrolytic caps in the primary to replace based on how they look, the ones you don't replace are gonna pop. The ripple needs to be tamed with new snubber caps, or they will smoke your new electrolytics quickly.

 

It'll be a waste of time to move past the primary power supply into the horizontal until the first issue is corrected. Everything builds off the heath of the primary supply - everything, including HV starts there.

 

I wouldn't be surprised if the waves you're seeing are just amplified ripple in the horizontal.

 

It's possible, nay even probable that the zeeners in the primary are leaking. Do you have an oscilloscope and a curve tracer? If not, I'd just replace them. As the rest of the supply comes up to speed... weak components will find themselves.

Edited January 30, 2017 by mojoatomic

[zander21510]

Looked at the TV a bit more last night, certainly were some crispy diodes over there, and some orange buildup like something splattered everywhere....but anyways I fired the TV up and set up my camera to record the symptoms of what it does and showcase the picture...enjoy!

 

[Keatah]

Put tape over the white lines, then you won't see them. It'll also give you the look of a wide-screen in a classic set.

 

Put a fan in there blowing on them hotted up parts, then it'll never shut off again!

 

:grin:

[zander21510]

Here are some more pictures...looks like something went down around that bulged capacitor...orange crusty residue all near it, and some scorching on the underside of the board. I think I'm gonna attempt replacing that capacitor to start, and go from there. Let me know if you guys have any other insight, thanks so much for the help!

 

 

 

[Keatah]

The crud and crust looks like damaged PCB material/coating. Heat from the diodes and capacitor. replace'em all.

[+-^CrossBow^-]

Agree...I wouldn't just replace the cap. If those diodes are toast (And they look to be), then that will only likely cause more voltage than should be going into the replacement cap and still cause issues. In fact the diodes going bad is likely why the capacitor in there now is bulged as it is.

 

Even worse though is to keep in mind that even if you replace everything in this section that looks suspect, that some other component that looks fine elsewhere could have been the original cause of it all.

 

But definitely start with that cap and the other components around it first to at least see if anything changes. If not, then you know something else needs to be looked at.

[zander21510]

Okay, got the capacitor out, gonna work on the diodes a little later on. So now, I need to buy a replacement, and so far I've been having trouble finding one that matches.

 

It says:

220µf (with the little tail on the u)

(M)

160V

 

I can find 220uf just fine, but all the voltages are under 50v, found one site that had 220uf and 350v....but they were out of stock. Any idea where I can find one, or am I just reading it wrong? Pic attached.

 

[Turbo-Torch]

Any decent electronics shop in your area should have 160 volt radials in stock.

Not sure why you're having a hard time finding one online, eBay alone has over 80 listings.

Go over 200v and the size of the cap will increase which may not fit in a cramped area.

[Osgeld]

http://www.digikey.com/products/en/capacitors/aluminum-capacitors/58?k=&pkeyword=&pv13=128&pv63=455&pv69=80&FV=ffe0003a&mnonly=0&newproducts=0&ColumnSort=0&page=1&stock=1&quantity=0&ptm=0&fid=0&pageSize=500

[zander21510]

Thanks everyone, found some on Ebay, sometimes I forget about eBay having that stuff lol.

[zander21510]

Well I got my capacitor, installed it, but no luck. Exhibits the same symptoms. But it's not any worse, so I'll consider it a win lol. I don't think I have the soldering skill or time required to replace all the scorched & crusted components around that cap, not to mention probably needing to unhook a lot of those wires to get a better look, so I think I'll probably leave it to someone with more knowledge than myself.

 

Besides...it introduces a new challenge to games: you never know when the screen is going to go off for 5 seconds!

 

[+-^CrossBow^-]

Well I got my capacitor, installed it, but no luck. Exhibits the same symptoms. But it's not any worse, so I'll consider it a win lol. I don't think I have the soldering skill or time required to replace all the scorched & crusted components around that cap, not to mention probably needing to unhook a lot of those wires to get a better look, so I think I'll probably leave it to someone with more knowledge than myself.

 

Besides...it introduces a new challenge to games: you never know when the screen is going to go off for 5 seconds!

 

2017-02-17 23.36.19.jpg

 

The only issue here is that while you have replaced the cap...since the other components weren't replaced along with it, the new cap is likely on a short life as well. So I wouldn't call it a win if the same issue still persists and you will likely be replacing that same capacitor soon.

[Keatah]

Electronic failures often cascade. Especially with higher than "battery-operated" voltages. One part fails and stresses another and then another. All the way down the line then something blows, and the whole chain breaks, or falls out of tolerance.

 

The older TV sets, despite being made mostly of discrete parts, still weren't made to be easily serviced. Still takes considerable skill.

[Osgeld]

The older TV sets, despite being made mostly of discrete parts, still weren't made to be easily serviced. Still takes considerable skill.

 

 

Good thing about them is they had plenty of space for big beefcake parts, so while this 30 whatever CRT is just starting to experience failures, a LCD of any quality is on leased time after the first couple years

 

Im not usually one to be "oh it was better back in the day" but in the case of big electronics, they gave you your investment's worth, vs now I bought a 240$ TV expecting it to die after 18 months (to be fair its on its 3rd year) I wont invest a shitpile of money on a new set today ... its just not the same like when my parents dropped a wad on a 32 inch CRT RCA and it went 25 years without fault

Edited February 19, 2017 by Osgeld

[7800fan]

Not all LCD are going to crap out in just a few years. I have a pair of 22" LCD monitors for computer (3 actually, one was a very cheap spare that hasn't been used for some time). They were made in 2007 and 2008 and right now one is just showing sign of failing backlight (uneven brightness, dimmer in middle)

 

I have a Vizio TV, 32" that works with almost all game consoles I've tried plus it also worked with DC using 15Khz via VGA/RGB port. It's going on 5 years old now. I would be pissed if it goes out and can't be repaired because most newer LCD TV do not have old NTSC RF support so older consoles wouldn't work unless modded. Most LCD TV do not have S-Video at all, and many have only 1 composite and component, that are shared. I would really hate to have to give up my 400+1 DVD player's superb video quality because it does not have HDMI, only component and beer glasses quality composite (Sony either screwed up on the design or my video output is screwed up) Also most newer LCD that still have VGA port do not support 15KHz either. :/

[zander21510]

Okay, so the TV died for good now, with nothing to lose, I'm gonna try to replace the electronics that look bad on the board, I got one of the black things off...according to the schematics in the board, it's CR401, +24V Rectifier. The only markings on it are a Motorola logo, and W 545-3 8537.

 

So any idea how I can identify these and get replacements? Picture attached, it's the far right one. (and yes, it does have 545-3 instead of 545-2 like the one in the center). Thanks!

 

[bpatte02]

Okay, so the TV died for good now, with nothing to lose, I'm gonna try to replace the electronics that look bad on the board, I got one of the black things off...according to the schematics in the board, it's CR401, +24V Rectifier. The only markings on it are a Motorola logo, and W 545-3 8537.

 

So any idea how I can identify these and get replacements? Picture attached, it's the far right one. (and yes, it does have 545-3 instead of 545-2 like the one in the center). Thanks!

 

2017-02-26 12.43.15.jpg

Good Luck! Love seeing these types of TVs live on. As always High Voltage is dangerous, so stay safe.

[Aldranis]

Been following this thread. Any updates Zander? My curiosity has piqued.

[SiLic0ne t0aD]

I also have an old mid 80's RCA Colortrak TV that my parents bought brand new, it's doing the same thing. It's actually a monitor with tons of inputs and outputs on the back. It's a real shame it doesn't really work anymore and though I'd love to see it fixed, I just don't know if it's worth it or not. I just have too many other projects that are more important to tackle that's gonna take me a year or two to complete first. Not sure if If I'm going to pitch it or keep it and try to fix it later on down the road.. If I get another big CRT, it'll be a Sony Wega Trinitron. I did partially recap my 32" Toshiba flat tube TV though and it's still running strong.. It was shutting down every few minutes but not anymore.