Older 40" Samsung TV to play around with! Score!!

[Terry01]

I got a new TV a couple days ago so I can now "reverse engineer" the old one! WOOHOO!!!!

I've been using an older style Samsung one,like from 10 years ago or longer I think.

The last new one i got before that lasted a few hours then one of my cats bounced of it and it tipped over and destroyed the screen. I took it to the dump not knowing i would get into electronics a few months later! I could have had fun with what was left. Only the screen was cracked,it was brand new otherwise. Sickener eh?

I got the one I'm going to "reverse engineer" just to tide me over and liked it so kept it for a year or so.
It's one of the first of the "big" tele generation! It's a flat screen with a speaker attached to each side and HEAVY as hell!
As in 2 men to lift it.....HEAVY!!

I'm really looking forward to opening it up and getting in about it with my new scope and stuff! There should be loads of learning to be had from it yet! In the end I'll get some bits and pieces from it too so win win situation! Not for the tele!!

Should be fun!

 

[kellys_eye]

Careful with your scope. If you get the wrong side of earthing you'll have a nice large spark and bang happening.....

Not a lot inside them these days. Older equipment - i.e. thru-hole mounted parts - are the best devices to get although if you have experience with SMD stuff you can salvage some useful stuff - the audio stages, speakers etc potentially some PSU parts, etc but generally there isn't a lot worth salvaging from old LCD TVs these days.

Still, it's a learning exercise and fun to do!

 

[Terry01]

Awesome warning on the earthing! I wonder how many scopes bit the bullet before the internet!

I have been watching a few videos on YouTube (EEVBlog) and doing a wee bit reading up on the earthing thing. I was searching YouTube one day and saw the header "how not to blow your scope up" and that got my attention and got me started. YouTube is a wealth of knowledge, good for beginners like me. I'll watch again before I go connecting anything up. Once i'm sure I understand 100% i'll connect my analogue scope up 1st just to be doubly sure I don't cook my new scope!
This will be the first bigger thing I'll have hooked my scope up to and probed around, only breadboard stuff and a couple little things I've "reverse engineered" so far. These wee things have been pretty simple too and well explained before I got near them first. The TV will have loads more to watch out for and be aware of when i'm probing around so i'll be popping a cherry of some kind!

Thank you very much for the warning. I bet loads of new guys have fallen into that trap. TBH I would probably have done so too had I not seen that video or found this site and you guys too. Its an easy mistake to make for over keen beginners like me to make. Having people around to sound these warnings "before" the mistakes are made is awesome, cost effective too! Probably saved the lives of many test instruments between you! lol

Taking things apart and finding out the how and why is the kind of electronics stuff I love. I suppose i'm more of a tinkerer than anything else. It's just so interesting and moreish! I can't wait till after Christmas and we'll have more new stuff so I can take the old stuff apart!
I've found that's a good way to get round the Mrs with my hobby. Buy her something new and while she's oh! ing and ah! ing I take the old stuff apart, Its done before she notices and no going nuts at me for "fixing" stuff

 

[kellys_eye]

A good investment is an isolating transformer. Ideally your whole workshop would run from it but using a smaller version is more cost effective and allows you to power individual items via it.

One rated at around 300W should cover most situations.

 

[Terry01]

Can you recommend a decent isolating transformer for me please?
I only have a small bench and would be looking to take minimal plugs from it. I've heard them mentioned a couple times now in the places I know is good sound information and guidance so I think like you say...."a sound investment"!
A couple videos I've watched and things I've been reading have mentioned them. The price range and selection is huge! Loads and loads!!
A educated suggestion of 2 or 3 to check out would be much appreciated if you don't mind??
I'd end up with the wrong one for sure if left to my own devices! I wouldn't fully trust I had the correct one if I went and got one myself.

Thank you...

 

[kellys_eye]

It's actually not easy to get a cheap isolating transformer these days. Heck, I've been trying for weeks to find one myself! eBay is the usual source (for me) but it's not the right time of year (I reckon).

I used to use a pair of industrial 240:110 (site transformer) wired back-to-back but that's not the best method (better than nothing) but it did cover the whole workshops needs.

Nowadays I rarely need more than 200W - I could get away quite easily with 150W - as most of the stuff that needs one for testing is very low powered. Even the biggest flat screen TV's rarely exceed 150W.

What I do have is a variable AC power supply (0-25V @ 8A) which I intend to modify to fit a second transformer in to step it back up to 240V (to give the isolation) and add metering to show V/I/W. There's a guy on Youtube that does test equipment repairs and uses a neat variable AC supply to power equipment and provides a safe and useful means of testing them. Naturally his gear is 'top end' but I reckon I could achieve a decent similar result.

Keep looking is all I can say but if you spot one on eBay don't be surprised to find me bidding against you!