I acquired this TV yesterday ($50 delivered) with "The colors are a bit screwy you will need to adjust it." but what I am experiencing is a total convergence failure. I have the service manual and have diagnosed (I'm pretty sure) a failed "Digital Convergence Unit" and have found a replacement for $75.

I was wondering if anyone else had any other ideas that could get me out of paying that $75. Is there a part of the DCU that is prone to fail? A cap or resistor? Is there possible a way to physically adjust the convergence? The CRT's are on spring loaded bolts, but something tells me not to touch them. I have checked for physical damage that may have occurred during delivery and can't find any besides a broken caster.

Otherwise the picture on this one is very bright and clear, not like the washed out looking big screens you needed to be 30' away from that I remember people having at the time.

This leads me to believe that this TV will last a while and may be worth the repair,

http://www.ebay.com/itm/Hitachi-Ultravision-60-rear-projection-TV-big-screen-60SX12B-for-parts-or-repai-/222152178774?hash=item33b94d3c56:g:ozAAAOSw-ndTozq6

If I had to guess... Two big convergence IC's, both labeled STK XXXX or something starting with STK. Near the two IC's, several resistors, maybe 8 or so. At least one resistor has failed, maybe more. Likely more.

Blue is really wonky on your set whereas red and green seem to be okay. You probably have one bad IC or just a bad resistor

So, if you want to do this on the cheap, you can try to see which IC is bad, if either, and figure out the resistor values, and just order what you need. The downside of this is the other IC could fail at any moment and you're back to square 1.

Or pay the $75 for the convergence kit, which should have better resistors, along with step by step instructions. (I'm assuming you saw the kit on tvrepairkits.com... they provide instructions) Fix it and not have to worry about it.

Just advice from a guy whose been there, done that, more then once.


Oh and another thing to check is the image brightness. Make sure it's not maxed out in the TV's menu. If it is the CRT's might be getting tired and the set's not worth your time. If you really want one of those behemoths you can probably find one that works fine, for the cost of moving it out of somebody's house.

Second on the STK convergence chips. They were always a high failure rate item. Here is the link to a repair kit including the chips and the resistors that fail when the chip does...

http://www.tvrepairkits.com/xcart/hitachi-60sx12b-convergence-repair-kit.html

Yup start at the STK's
Almost all brands have the same set-up. Look for cold joints
then the low watt resistors. The voltage to run them comes off the FBT
and often is both plus & minus supply. They are typically fused
by apx 1 ohm resistors. Use flameproofs NOT old carbons. An open
resistor will point to a shorted STK or rectifier diode.

73 Zeno:smoke:

I covered the blue and now the menus are readable and it has an excellent picture minus the absence of blue. Honestly I'm color blind anyway so it doesn't look too bad to me. My problem color is red, if red were out I would probably never notice on my own. My kids get a lot of practice helping me with resistors and color coded wires, before them it was following traces on schematics no matter what.

That is the same kit I found, and I think I am going to go for it. This might just be a great TV for my 90's living room. It might be a month or two before I actually do it though, I spend a lot of time fixing other people's stuff and don't get much time for my toys.

Zeno, just seen yours. I'm going to check, but since the chips are so prone to failure I will replace them anyway, do some serious dusting, close up the TV and hopefully be done.

[QUOTE=slatton86;3165290]Zeno, just seen yours. I'm going to check, but since the chips are so prone to failure I will replace them anyway, do some serious dusting, close up the TV and hopefully be done.[/QUot
We didnt do much projo but any with conv problems got the IC's
even if it was just cold joints. Thats more for a cheap-out but since
you will be using it change it all is best.

73 Zeno:smoke:

...

I spent a lot of time in the TV last night cleaning and checking things out. Looks like I have 3 STK-4274's. All the resistors seem to check out, but the blue stk doesn't heat up so I believe it's dead. I have dealt with these STK's before in old receivers and have replaced them, then added a fan with success. So I think that is going to be the plan here. Too bad I don't have any of those old receivers laying around now I could scrap one from, but I'm sure I'll find one the day after I get the TV fixed.

I would *really* replace those resistors too. Even if they check out now, don't trust them.

...

I would *really* replace those resistors too. Even if they check out now, don't trust them.

I should have mentioned that I have a hunch that they have been replaced from the originals already. They actually look pretty new, and so does the DCU mounted upfront encased in a small metal box. The DCU also had a screw with a stripped head and had electrical tape(WTF?) to help hold it in place. The STK is definitely original.

I was up at 3am doing this and didn't take notes for some reason. My brother in law stopped by when he seen the lights on and we watched side 3 of Ransom(my testing LD, I was working on a customer's player as well) on this TV in a mix of "super green" and "the blue haunting" and even debated playing Sonic or Megaman with the blue covered for a laugh.

Oh. Then you might get away with just the IC...

But if the resistors were replaced and check out and the IC went bad... there might be something further up the line causing your problem. Still might as well start with replacing the IC and hope for the best.

2 more questions on this TV. I really appreciate the help from you guys so far, I know this isn't exactly what your are into.

1st is discharging the HV. I'm not a big fan of the way the service manual says to do it (adjusting it down while the TV is on) and I don't have a HV multimeter anyway. So does anyone have any other ideas?

2nd and this is an idea from my wife. Would a newer projector be able to make an image on this screen if mounted inside pointing at the mirror on the back panel? I know it would take a lot of tinkering to get a centered and focused image on the entire screen. If it works though this could be the living room TV and we could move the 32" LCD to the bedroom. Our living room has been taken over by the kids who require HD for Minecraft to work properly.

That second idea is not my cup of tea, but it would still be interesting if it worked.

I honestly like the idea of going ahead and getting the kit replacing all three STK's and do the resistors too just to be sure, add a fan, then building a computer into it (I have an old P4 board and Geforce 4 or '06 Intel MacMini on the shelf that would be perfect) and fill it with emulators and 5/6/7/8/90's TV for my office/shop.

CRT TV repair is still something I am just looking into. I have always been intrigued by the older TV's and have always loved visiting older people that still had a running set from the 50's and 60's, I also have a sweet spot for high end early 80's consoles with large speakers on both sides. From what I am learning here though, it is tedious work and not much profit involved. I do have to support a family of 4 plus we have been helping my brother in-law and his wife stay on their feet.

I also still have that 23" GE B&W I'm going to pull the chassis and go to town on someday. Maybe build in a roku with a paid up Hulu subscription and try to sell it if the CRT isn't too far gone, I know it will need a rejuvenation.

A regular projector won't project as large of an image, and the keystoning will be way out of whack.

I got some answers for you on this believe it or not...

Discharging the CRT's... that thick wire that runs to the anode cap can be disconnected from the flyback. Exactly how I'm not sure, but it does. HV is fairly low, around 9 KV or so. I believe you can discharge the HV to chassis ground without any ill effects. That's how I did it when that Phillips needed a coolant change in the green and blue CRT's.

As for mounting a projector in the TV so as not to deal with the hassle of CRT's and convergence... I have also tried this. You'd need an extremely short throw projector, something capable of making a 60" image from 20 or so inches away. As in, it's not possible with your run of the mill projector.

I got some answers for you on this believe it or not...

Discharging the CRT's... that thick wire that runs to the anode cap can be disconnected from the flyback. Exactly how I'm not sure, but it does. HV is fairly low, around 9 KV or so. I believe you can discharge the HV to chassis ground without any ill effects. That's how I did it when that Phillips needed a coolant change in the green and blue CRT's.

As for mounting a projector in the TV so as not to deal with the hassle of CRT's and convergence... I have also tried this. You'd need an extremely short throw projector, something capable of making a 60" image from 20 or so inches away. As in, it's not possible with your run of the mill projector.

Maybe some used Epson BrightLinks from school systems? I almost forgot about those. Expensive as hell though.

Oh I'm sure something exists that could fit inside one of these TV's and fill the screen with a bright, sharp image.

But the cost would make doing this ridiculous. Much easier and cheaper just to fix the existing chassis.

And don't buy cheap generic stk chips. you will just be pissing in the wind buy oem sanyo replacements.

And don't buy cheap generic stk chips. you will just be pissing in the wind buy oem sanyo replacements.

This reminds me when I repaired my Sony CDP-101, the worlds first CD player from the early 80's. It used stock, STK chips for the servo controllers, and they failed of course. I found replacements that emulate the purpose of them with discrete components, far larger and needs a heatsink, but still works!.

Until now I always thought "short through" was a lens that you could put on most projectors. I can find some older models pretty cheap and I've seen some with cosmetic damage even cheaper. I was looking for one of those stupid $20 pocket projectors from China to play with, but of course they are no longer flooding eBay now that I thought about getting one.

I would have to remove the CRT's so I could mount the projector without it getting in it's own way and that would give some extra distance. I wonder if these CRT's would sell to cover the cost of a project. They are low hour and the coolant is not foggy at all.

It sounds like a fun thing to play with and could be interesting, especially if some one starts making fun of my old TV and I turn it on to blow them away with 4K, haha. I don't think I will be investing in 4k at all though.

Looks like this thing will sit for a bit while I work up the $75 for the kit, wait untill I have a weekend, then there is the remote to deal with. You have to hit PIP+SWAP (IIRC) to write the rom after getting it set up. Magic Focus" still seems to work fine for the green and red after I do a reset with the service switch, so I am thinking that might not be a huge issue. I can "rent" the remote for $20 (80-$60 upon return) or wait for it to pop up on eBay.