Working on Superbeta SL-HF600 part 5. Counterfeit components.

[@alphabeets]

This channel is catnip for us videoheads. Thanks.

[@kelvingreen3736]

Only just a minute in and you’ve mentioned 12 volt vids. He is where my trip down the you tube repair rabbit hole began. Love your videos by the way. 😀

[@SilvaD702]

I feel your pain and I don't trust any stk device! 15 or so years ago when I was fixing Mitsubishi rear projection tv's it was almost guaranteed you'd get a fake convergence amplifier ic's. The pn's I remember are stk-392 and stk-393 and I remember acetone removing the markings

[@yellowcrescent]

I'm guessing the modules are actually real STK5441 regulators, but have been pulled, remarked, and the leads have been re-tinned -- so you have no idea if they are working or not. Usually tinning on the leads will give it away if it is supposed to be a "new old stock" part. The plastic pattern to me just looks like an injection molding flow pattern with high GF/fiberglass content, although the grinding marks def don't seem original... I guess worst case scenario, you could make your own daugherboard with some 7800-series regulators.. at least then you know it's good :D

[@thebreretons]

If you haven't already got it the service manual for that model is available on-line and shows block diagrams and voltages for the STK5441.

[@zx8401ztv]

i had a look through my pcb box and just one stk5481 dam!! and finding propper data sheets seem difficult to find. Perhaps you can find a sheet for the 5441 and connect a few multimeters to the main regulated lines, say 5v and 12v.

[@crashbandicoot4everr]

The 5481 was used on many JVC VHS machines of that era. Worth trying to adapt it to work on a Betamax? That would be funny lol...

[@zx8401ztv]

@@crashbandicoot4everr Well that's up to colin, i would be attaching wires to the 5481 to the pcb,. Donkeys years ago i had a friends vcr and the stk regulator was faulty, i found it was a missing 12v supply, so i bodged in a 7812 regulator to a heatsink but the 12v was switched on all the time. So (Very bodgy) i stuck a relay in line with the 7812 feed and a resistor + transistor pulled in the relay when the On button lit up lol. Worked perfect, even on the timer recordings. I was a bit determined that the £30 regulator was a bit too much. Sorry about the long waffle.

[@superbetahifi]

Hello! I bought some STK-5441's from eBay a year ago. Installed one and it has been fine. Maybe they are extracted from scrap machines and refurbed, so reliability will be hit-or-miss.

[@video99couk]

Do you have a spare which you could sell?

[@crashbandicoot4everr]

Unfortunately the market is flooded with Chinese couterefeit transistors and ICs. Even reputable strores are stocking them without the managers/owners realising they are being supplied with counterfeit parts. The STK5441 wasn't used on UK/EU models so finding an original known-good one would be difficult. The SL-T25, SL-F25, F30, F35 and F60 use the 711B2 chassis and they are PAL machines but they don't use this regulator IC either.

[@Ragnar8504]

That's good to know, one less thing to worry about with the SL-F73 I got a while ago!

[@phelissimo_]

Very interesting!

[@frankowalker4662]

1951 LOL. Not sure about the replacement you got either, they have got very good at changing the part numbers on devices these days.

[@superbetahifi]

Unrelated question if I may: Could I transplant video heads (or entire drum assy) from a non-hifi unit (SL-100) into a hi-fi unit (SL-HF400) and get hi-fi audio? Thank you!

[@video99couk]

Answer would depend in part if you are taking about NTSC or PAL. NTSC maybe, PAL certainly not.

[@superbetahifi]

@@video99couk thank you for the quick reply! They are NTSC units. It seems to me that if the geometry of the video head discs are the same, it should work. The hi-fi circuitry of the 400 should be able to decode hi-fi audio from either head disc, but I haven't seen it done or discussed. Funny that PAL has an SL-HF100, but NTSC has the SL-100!

[@irtbmtind89]

Sadly I generally assume most STK modules for sale now are fake or counterfeit, as you can't easily get them from reputable sources anymore. This is a pretty well known issue among audio/hi-fi people. You might have better luck if you can find the Sony part number and search for that instead.

[@bobsbits5357]

hi i have seen alot of fake in the past you are right they do look just not right is there any thing you can put in there to do the same job

[@MrBetaByte]

Really so sorry this didn't work out but as soon as you said 'from China' in your previous video i knew it wasn't going to end well. I have thought about modern equivalent power supplies but not had much opportunity to really play with the idea as so far I've been lucky and found genuine new old stock STK's that have held up really well. I did check for the STK5441 for you but they are well and truly long since gone. Really so hope you do find a good replacement and I'll keep an eye out for one for you too.

[@Capturing-Memories]

I ordered a lot of electronic components from eBay as being new old stock and I was shocked to how they even fake the packaging to look like an old stock item, Chinese counterfeiters have a special place in hell. I have a parts donor, the SL-2500, If it has one I can send it your way to Europe but not sure if it's going to be in good working order since the deck is defective and have no way of testing it, it's all taken a part.

[@crashbandicoot4everr]

Have you seen the videos where they reseal iPhones and stuff? It's crazy. The SL-2500 uses a switching power supply with no STK-type IC.

[@Capturing-Memories]

@@crashbandicoot4everr Bummer.

[@snap_oversteer]

Fake parts are huge problem in old computer space, especially things like Commodore 64 SID chips where some years can be very valuable and hard to find, and even the original chips are slowly dying nowadays. With some chips like Yamaha OPL2 you can find some good working counterfits, which most likely are used pulls cleaned up and reprinted with nonsensical manufacture dates.

[@feuermurmel]

11:44 Those blotches and lines look like weld lines to me actually, an artifact of injection molding when the plastic has to flow around the mold in two directions and is meeting on the other side, already cooled down a bit. The plastic won't form a clean surface at and around that line when the process isn't controlled carefully. Not necessarily a sign of counterfeiting, but a sign of doing things cheaply. Nice video explaining explaining that: kzbin.info/www/bejne/f5qqhZ6iacuGrpY

[@video99couk]

It might be that the part from China is genuine. The part that was in the machine originally was certainly fake.

[@wdavem]

I thought I heard these things sometimes come from "working" e-waste. Someone has a business de-soldering and laser "cleaning" and re-numbering these horrible modules. So when you receive the part it looks unused. Chances are last time it had power it was fine. But then (sometimes) whatever the hell happened to it starts to work in it's magic and then the magic smoke comes out; or it decides to do the strangest possible things such a device could ever do. Maybe the new numbers kind of denote which type of disaster or horrible situation it was in. I don't mean to condone or condemn it 🤭but... BEWARE ridiculousness and potentially destructive chaos... etc.

[@redwolf92]

I just consider them to be an unofficial OEM part, lmao.

[@alphabeets]

Your best bet might be to find a cheap broken device that has a genuine part in it that you can pull the SDK from.

[@jamesbennettmusic]

Have you tried the acetone trick? Try rubbing it with acetone on a cotton bud... if it's been painted over, the paint will come off. I had my fair share of ground and painted chips (and some unhelpful sellers) last year. Misery! They could also be genuine STK's but not the right part number, but just ground down and a new unmatched number stamped on them.

[@pierrejeanf.dupuis4150]

Watch some Commodore 64 chip videos for good counterfeit chip info (how to identify). Pretty sure a cotton swab with rubbing alcohol picks out most, but probably not your second example. In fact totally different subject matter. In fact I'm rather rambling on here, aren't I? Pretty sure the jist of it was - don't buy cheap (vintage) parts from China - not if there is a similar looking less in demand product that can be rebranded. Not sure why the Chinese authorities will pay the 6 Euro (less on bulk no doubt) in-nation shipping fee, plus international shipping to provide free shipping on a 95ct item. But they do. When you look for a 2TB USB stick on Ali and see hundreds for under 5 Euros, you know they won't work. Oldest trick in the book. And they still keep doing it. So selling rebranded chips taken from old discarded fax-machines must make sense somehow. Spending a day rebranding a 2ct part may be worth it in rural China? 10.000 Yuan and a medal? Or possibly Chinese sellers are now getting fake vintage stuff from Bangladesh and just don't care what they sell? Buy cheap, sell high? Rambling on again, aren't I? Oh, dear. ;-)