• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Found this

throbscottle

Well-Known Member
Dunno, I have quite a few NPN transistors marked 1L. Bet I can find most of what I've got in there. All my stuff is old though, unless I've actually bought it (happens, just not often!) in which case it's merely dated.

But yes, most of the on-line SMD lists are very limited. I posted this one because of it's size.

OK harder challenge. I bought some BSS84 mosfets recently, top mark VT is not in the 2014 Turuta book. Now check the website and..... nope, not there either.
I wonder if they get their info from the same place?
 

Externet

Active Member
It was revealed to me a long time ago by a manufacturer that the markings on surface mount components are arbitrary for that production batch to be distinguished from other product batches. Next day can be another marking for the same device ! :banghead:
Sounds like the wife of whoever is doing the production of that component that day being Lucy, is enough for him to stamp 'LU' on the package. The real information is printed on the reel referred to LU. :confused:
 

Nigel Goodwin

Super Moderator
Most Helpful Member
It was revealed to me a long time ago by a manufacturer that the markings on surface mount components are arbitrary for that production batch to be distinguished from other product batches. Next day can be another marking for the same device ! :banghead:
I've often suspected as much :D

As I'm involved in repairing equipment for which there are no schematics or spares available (the manufacturers won't supply them) we have to do a lot of 'reverse engineering' and trying to identify components is a large part of that.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Nigel;
do you think that we are approaching the point of electronic devices becoming fully non-repairable?
It depends on what you mean by 'repairable' - the never ended quest for cheaper and cheaper electronics - thus meaning no spares, schematics, or service support, looks like we're not far off now.

But by reverse engineering, and hopefully been able to find sources for required parts, it means repairs can often still be done - the other issue of course is are people prepared to pay for it?. An electronics service engineer is far more highly skilled and trained than an electrician or a plumber, yet both of those are far more highly paid occupations.

As we work on professional equipment, which comes with professional prices, we can happily charge professional fees for repairing it :D
 

schmitt trigger

Well-Known Member
That is what I suspected.

More over, let's imagine that a programmable device like an microP or FPGA becomes damaged.
Without the associated firmware, that device becomes un-repairable.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
That is what I suspected.

More over, let's imagine that a programmable device like an microP or FPGA becomes damaged.
Without the associated firmware, that device becomes un-repairable.
Absolutely, luckily they are generally very hardy devices.

However, for an example of not been - a particular Sony CRT chassis had a problem with LOPTX failures.

The sets would come in dead, and the LOPT transistor would be S/C - so, initially, you changed the transistor and turned the set ON. There would be a loud crack from inside the LOPTX, and the transistor would instantly fail again. You soon learnt NOT to just change the transistor, as they didn't just fail for no reason.

However, a more serious problem was that it also sometimes (quite often) took out the main micro as well, a large SM device made by Philips Components.

Interestingly the identical chassis was used in 16:9 sets and 4:3 ones - and in the 16:9 sets probably 75% of sets killed the micro when the LOPTX went, where hardly any of the 4:3 sets did.

So the procedure became:

Is it 16:9?

Is the LOPT transistor S/C?

Give an estimate for transistor, LOPTX and the micro.

Is it 4:3?

Is the LOPT transistor S/C?

Give an estimate for transistor and LOPTX.

I've no idea if the micro would still be available now?, but it was up to when CRT died out - and obviously if it's not available, there's nothing you could do with one where it had blown.
 

Latest threads

EE World Online Articles

Loading
Top