DISASSEMBLY and REPAIR: Sony Triniton CRT TV model KV-14M1E

Sony Triniton CRT TV model KV-14M1E from 1999/2000

Now that LCD TVs are the kings (not for long) and with digital TV signal replacing the older analogue one, CRT tvs are pretty much depreciated and seem to be pretty much useless. Well not really and not by me certainly.
I was given two TVs, being one of them the well known Sony Triniton CRT TV model KV-14M1E that was suffering quite badly from convergence problems. I didn't even knew the name of the fault until i really searched about it as i never had to dwelt with it. I'm still in the process of learning about CRTs and i must admit this was interesting to fix but also quite a pain.

And this is how the image quality looked like. You can notice that it is quite terrible. It isn't out of focus. The problem is "convergence purity". As you might know, every color can be composed from three basic colors. RED, GREEN and BLUE. This is how CRTs and LCDs make colored images. CRTs use 3 electron guns, one for each color. The electrons from each gun must hit perfectly on the same spot on the phosphor surface inside the CRT.

So basically there is a misalignment of the three guns and they are not overlaying the electrons correctly on the screen, creating this fuzzy image, Notice that even the subtitles are hard to read.

  

 So i opened the TV. There was dusty mess inside as expected, especially around the high-voltage area of the TVs motherboard.

 A view of the other side. The latest CRT tvs were quite empty when compared to older tvs that were usually full of daughterboards!

 

 Here is a view of the back.

 Here is a before-after cleaning picture. Thank you air compressor, you have served your purpose.

 Ok. Now lets analize the problem. At the beginning i was a bit lost where to start. I knew i should start searching for some adjustment trimmers before assuming there was some electronic malfunction. But the only two obvious adjustments inside the TV were "FOCUS" on RV704 and "SCRN" on RV703, and none of them sounded right. I went ahead and talked to a few guys on the UK Vintage Radio Forum (thank you guys, you were awesome) and there i found some pretty knowledgeable people about this particular TV chassis. Turns out i should search for some adjustment saying H-STAT either on the crt's pcb or on the yoke itself. Unfourtanely there was nothing like that on these newer TV sets which led me to a last resort solution.

I needed to mess around a bit with something here on the back of the CRT.

This was the thing to mess with. You only want to mess with these as a last resort as it can get worse if you're not patient enough. These are convergence purity magnets.

 

These are composed by magnet rings. You should rotate each one at a time really slow so that you notice what they are doing until you get a desirable result. There can be a few of these and it can be tricky to get the perfect combination. You can either take 5 minutes to half-hour depending of how perfectionist you are.

 Before starting you should have a image pattern generator. I didn't have one so i used a computer with TV OUT. Unfourtanely my modern day computer didn't like the Sony TV and the only computer i had left with TV OUT was an old Pentium 1 120mhz. Lucky me heh?

This is the best image to use when aligning a crt convergence.

This is how it looked. Don't cross your eyes, there is nothing wrong with them. This TV had a seriously bad convergence purity problem.

Here is a closer look at it. You can clearly see that the three basic colors are completly misaligned. Inside the squares you should have one dot only instead of 3 separated colored dots (three basic colors, RED, GREEN and BLUE).

 Having a mirror facing the TV while doing this is a must.

 

Since this was a really small TV i also used a webcam poiting at one of the dots. But this isn't quite a good help because you wont get a even pattern on the whole screen.

And this is the result after a while. Some CRTs can be more picky than others and take you more or less time.

I did a new marking on the convergence purity magnets which is highlighted by the red rectangle. Notice the older white marking above completly jagged. That's how much i had to move the ring magnets.

Probably you won't get a 100%  RGB match (RED, GREEN BLUE) across the whole screen. The corners will probably look like this or worse. This can be fixed by using a strip with permalloy. These are called, you guessed, permalloy strips.

This TV happen to already have one and since i already messed around with the magnet rings, i had to realign the permalloy strip so that the corner looked better.

 The permalloy strip removed from the CRT.

 The permalloy strip realocated. This isn't the best way of doing it. I used electrical isolation tape to hold the permalloy strip in place, but doubled sided tape or hot-glue should work better in a long term.

This is the final result. Notice that the subtitles and even the channel's logo are much more clearer now!

DEMO, DISASSEMBLY and minor REPAIRS: VR312 VHS Philips VCR

Philips VHS VCR model VR312 from 1992 with the Charly Deck Mechanism

This is the VR312 VHS Philips VCR from the year 1992. This was my first VCR..actually, this one i got it last year through a seller on some site i can't recall right now. My original vcr is long gone and today the only things i have left from it are a few mechanical guts and boards for spare parts. I have given the case of the vcr to a friend of mine that wanted to transform it into a media center computer for his living room. I might show that one day here.

But today i have this PHILIPS model, which is the exact same model that i had 20 years ago. When i first saw it on the internet i couldn't let it go, i had to have it. I have so many found memories of it. So many tv shows and family movies went through it, so many afternoons disassembling it away from my mother, eventually killing the vcr with so many tear downs.

I have to say, i have never saw any more models apart from the one i had and this one i got now. Has anyone ever got this vcr?

Let's have a look at it shall we?

This is how i got it on mail. The DHL van was involved in a serious car crash leading to one of the drivers dying on the spot. I'm deeply sorry for him, my deep condolences to the family.

The VCR wasn't in very good shape. The front housing was detached and the protective foam found it's way into the whole unit.

I didn't know if i was to be mad at the seller for not putting the VCR inside a plastic bag to prevent this from happening or if i was about to laugh out loud.

Everything fixed, i only have missing the control door and the remote control of the VCR.

I asked to my friend my old VCR door, and now i own him a replacement. So if any of you have anything like this and you're willing to selling it, contact me at totalrandomtechnology@hotmail.com .

Has you can see the motherboard has a small dark bruise on the bottom right corner. That happened because of a leaky battery underneath. These always go bad after 15 years so it seems.

This is the Philips Charly deck design, some love it, and some hate it. I love it until i have to fix it because it's quite a complex mechanism if you're not much into it. No rubberized idler wheel. What a must, at least until the gears get brittle and break which would make it even more unfixable than just replacing a few belts! This VCR has 3 belts, all still in good shape as well as the pinchroller.

Here you can see the battery that i was talking about.

A better view of the main board.

Here is a view of the vacuum fluorescent display full of alphanumeric digits. I really enjoy this in a VCR this old!

A view of the back of this board.

And now the powersupply. This is a switching power supply type, and the filter capacitor was bulging a tiny bit. You don't want to mess with these and leave them inside like that, because when they fail, it can get catastrophic. Also, be aware of the high voltage stored inside the capacitor, even if the VCR has been plugged of the mains for a while.

I went ahead and decided to replace all the capacitors inside the power supply. Better to be safe than sorry. The smaller ones seem to still be ok so i'll keep them for small projects or experiments.
Oh, and notice the leaky battery.
By the way the video playback looked a bit better after this but i could be wrong about this, it was a really minor improvement.

Yummy?

I got the remote on ebay. It was a pretty lucky find.

Here with the cover opened.

Last but not the least, the instructions manual.
All in all, this VCR uniqueness is in it's deck. Reminds much of betamax decks! I should get more of these!

DEMO, DISASSEMBLY and REPAIR: Aiwa Walkman HS-G35MkII

Aiwa Walkman HS-G35MkII

I always had a thing for walkmans, and funny thing is that none of the walkmans that i had when i was little is still with me. They all had horrible deaths...i still remember the one that ended under a bus tire..i didn't know a walkman could do such loud crunshing sounds!
Well today i have with me the Aiwa Walkman HS-G35MkII from 1987 and this was bought on the internet as a COMPLETLY new and NEVER used walkman, only turned on once for testing purposes, and since this was a quite popular walkman from the Aiwa brand back in the 80's, i had to grab it.
Although in really good condition, the seller was lying with all his teeth as the walkman was used quite a bit. The capstan, the pinch roller and the reading head had strong evidence of quite more than "just one minute os use" in it's entire life.
To make matters worse..there was nearly no sound output at all! I had to put the volume all the way up just to hear the tape playing really low and noisy only on the left channel. Not to say that the equalizer controls on the tape door were not functioning correctly. Also, you will notice in the video that something missing on the back....Anyway... i went ahead and tried to fix the poor thing!
 

Can you already guess what was wrong with it?

Yes, bone dried and leaky capacitors. I had to replace a few but since they were all from the same brand, i went ahead and replaced them all. Problem was that i couldn't find exact matches and the replacements were quite bigger...imagine trying to put huge capacitors in the place of little ones next to a walkmans complex mechanism full of moving parts!

Time to tag some wires, because if i was going to recap this walkman then all wires had to be dissoldered!

Strangely but gladly the belts were all in mint condition!

Here is one of the new capacitors in place, and as you can see two others that are laying down on the pcb. I'm not proud of this, but that's what the local store had at the moment. And no, i was not willing to buy capacitors from the internet, not worthy!

Here is another example of two other capacitors struggling to fit!

A closer look.

Now it's all done and working perfectly. Please view the video demonstration!

Walkman vs Ipod Nano :)