DaveG, great! Thanks for the pix!
These look like the J74BL parts I got scammed on.
Mine have a "W" or "M" in the mold mark - a round spot - on the curved side.
LAJ, I've been saying exactly this for about 3-4 years! Nobody seems to notice.
Unfortunately the great flood of CRT computer monitors and TVs has almost ended now. I grabbed as many as I could, but in reality, that wasn't that many. They had a wide selection of passive and active devices, bipolar and mosfet both.
These look like the J74BL parts I got scammed on.
Mine have a "W" or "M" in the mold mark - a round spot - on the curved side.
LAJ, I've been saying exactly this for about 3-4 years! Nobody seems to notice.
Unfortunately the great flood of CRT computer monitors and TVs has almost ended now. I grabbed as many as I could, but in reality, that wasn't that many. They had a wide selection of passive and active devices, bipolar and mosfet both.
Found a 27" Panasonic TV last week...
on the side of the road. It was only about 5 years old. Had a broken solder connection on the vertical chip.
But I don't see as many CRT computer monitors as I used to. Although in recent years I've found two flatscreen computer monitors.
So I think it depends on where you live.
on the side of the road. It was only about 5 years old. Had a broken solder connection on the vertical chip.
But I don't see as many CRT computer monitors as I used to. Although in recent years I've found two flatscreen computer monitors.
So I think it depends on where you live.
Nah about two years or so ago there were daily lots of CRT monitors at each and every garbage nite here... next to nothing now. It's over. Most have been replaced.
Sure you find some... wonder how many new bits of electronics will show up with bogus parts, and have a failure?
Hope none make it into critical aerospace or medical gear. Geez.
I tell ya, there oughta be a law!
_-_-
Sure you find some... wonder how many new bits of electronics will show up with bogus parts, and have a failure?
Hope none make it into critical aerospace or medical gear. Geez.
I tell ya, there oughta be a law!
_-_-
Looks like there are more people involved than a few hobbyists.
Have a look at this report:
"Inquiry into counterfeit electronic parts in the Department of Defense supply chain"
To find at www.gpo.gov/fdsys/pkg/CRPT-112srpt167/pdf/CRPT-112srpt167.pdf
Onra
Have a look at this report:
"Inquiry into counterfeit electronic parts in the Department of Defense supply chain"
To find at www.gpo.gov/fdsys/pkg/CRPT-112srpt167/pdf/CRPT-112srpt167.pdf
Onra
There are parts, in particular actives and opamps, for which one may not be really sure if it's a counterfeit. It takes time and resources to measure and compare against known-good parts, and it still may not be conclusive. By that time, 60 days may have passed or it may have gone off the radar, because the value of the transaction may be too small to waste time on it. That's one of the reasons why there may be no negative feedback for some dodgy transactions on EBay.
2SC2922 / 2SA1216 2SC3284 / 2SA1303 not fake
Mr. Jacco Vermeulen...you have a lot of DIY experience.
Sanken 2SC2922 and 2SA1216 LAPT ring-emitter transistors are they still in production, and where can buy genuine parts ?
As you know these two types shown are 200W / 180V / 17A. MT200 house two screws.
Here in the stock I have four sets 2SC3284 / 2SA1303 also LAPT also multi emitters but only:
125W / 150V / 14A TO-3P house one screw.
Are they still in production?
Where do I search for non chinese stuff?
Kim
Mr. Jacco Vermeulen...you have a lot of DIY experience.
Sanken 2SC2922 and 2SA1216 LAPT ring-emitter transistors are they still in production, and where can buy genuine parts ?
As you know these two types shown are 200W / 180V / 17A. MT200 house two screws.
Here in the stock I have four sets 2SC3284 / 2SA1303 also LAPT also multi emitters but only:
125W / 150V / 14A TO-3P house one screw.
Are they still in production?
Where do I search for non chinese stuff?
Kim
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2SC5200 2SA1943 fakes
Got 10 pairs. ....the 2SC5200 looks like genuine Toshiba's ....all 2SA1943's looks like they have been made upon a kitchen table.....never looked at them, just bought for amplifier repair and then in stock.
....take a look at the close-up 2SA1943 JPG.....thin solderlegs , bad finish and a backside metalpiece formed and made with chisel and hammer compared with the original 2SC5200 Toshiba transistor.
I believed I were on the safe side as far as OP-transistor repair was concerned....but obvious I am not!
Any experience out there?
Got 10 pairs. ....the 2SC5200 looks like genuine Toshiba's ....all 2SA1943's looks like they have been made upon a kitchen table.....never looked at them, just bought for amplifier repair and then in stock.
....take a look at the close-up 2SA1943 JPG.....thin solderlegs , bad finish and a backside metalpiece formed and made with chisel and hammer compared with the original 2SC5200 Toshiba transistor.
I believed I were on the safe side as far as OP-transistor repair was concerned....but obvious I am not!
Any experience out there?
Attachments
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If they're difficult to get in Denmark, order direct from Profusion in the UK.
(the Sankens, and all other Japanese semi-parts, have been available here for 3 decades. A couple of years more than I have bought them, so it comes free. The DIY experience I have in general will likely scare you)
Thanks for the UK link...I am not that easy to scare
I am sure that you got experience. The supplier I bought the Toshiba's from promised me 10 new pcs of genuine Toshiba 2SA1943.
My experience and my measuring equipment is not enough to evaluate a difference between the Chinese and Japanese transistor types, but my genius of a buddy can do it.
I shall try to return with some measurements of the two 2SA1943 transistor types.
Hey folks any way to tell if a transistor is a fake or not by picture, or has anyone purchased Toshiba 2sd845/2sb755 from ebay seller.
I was looking at these,
1pair or 2pcs Transistor Toshiba MT 200 2SB755 2SD845 B755 D845 | eBay
all so how do I want these matched, I was told I did, and didn't but if I can get them matched that would just be better regardless.
Thanks
I was looking at these,
1pair or 2pcs Transistor Toshiba MT 200 2SB755 2SD845 B755 D845 | eBay
all so how do I want these matched, I was told I did, and didn't but if I can get them matched that would just be better regardless.
Thanks
I'd be careful of ANYTHING from China. I worked for a nonvolatile memory company, and you wouldn't believe how much counterfeiting has been going on in the last few yrs. Some assembly house in SE Asia would take either a commodity die and package that up, then sell it as a our device (of course at a premium price). Sometimes we would open up the package all to find NO DIE inside, no wire bonds, just a lead frame. These assembly houses even got our part marking to the point where we had a hard time identifying it as a counterfeit, they would copy previous date code and lot code combinations. And of course copy the logo pretty well.
The main problem is that all this junk in going thru the brokers. If you buy from a non-authorized distributor, all bets are off.
The main problem is that all this junk in going thru the brokers. If you buy from a non-authorized distributor, all bets are off.
this URL with various die-Images Looks interesting:
Index of /repairbasicsforbcae1/images/transistordiesx
Index of /repairbasicsforbcae1/images/transistordiesx
I've bought 200 of (supposedly) 2SC2878 transistors on eBay, marked "C2878 GR 7E". . These are fakes. The Vebo is only about 7-10V, like on the majority small signal n-p-n transistors, and the reverse gain is only about 15-20. On the real 2SC2878 the reverse gain is over 150 (typical 250) and Vebo is over 25V (I've measured up to 75-80V). The capacitances are also different. I suspect that all transistors marked "C2878 GR 7E" on eBay from China (there are many offers at the moment) are the same fake devices.
Cheers
Alex
Cheers
Alex