- Sheesh - 2 Updates
| "jurb...@gmail.com" <jurb6006@gmail.com>: Mar 10 08:31PM -0800 On Tuesday, March 2, 2021 at 9:47:32 AM UTC-5, ohgwrote: > > inspection. Rubbish. > > RL > We've all seen flat out counterfeits. When I used to repair an amplifier with blown outputs, I used to return them along with a copy of my do's and don'ts - things like checking for wayward strands of speaker wires, looking for speaker wires punctured under carpet strips, not doubling up speakers on one terminal block, leaving sufficient ventilation on top of the amplifier, etc. I remember when I had amplifiers coming back with reblown outs, and I blamed the customer. Turns out the semis I was buying were counterfeits, and it wasn't just audio transistors. We ran into this problem with television vertical output ICs, power supply ICs, horiz (line) outputs, STK convergence modules, and even Sony jungle ICs.. I remember going through my parts supply and tossing a good portion of them out and making sure to buy from only reputable suppliers or directly from the OEM. You ain't shitting. What I don't see is how they can go to all the trouble making counterfeits that actually work but are like underrated for the job. If you are going to make ICs why not just make them right ? So now I got this Pioneer QX-747. It had so many bad transistors it ain't funny. Three channels of the power amp and then one other board they call "equalizer" and now the SQ decoder. Not one power transistor or capacitor bad. It ran me out of elcheapo small signal NPNs ? I don't even remember how many I had, but I just ordered 25 more. (hope that does it lo, naw it will) I guess it is my fault, the guy said quad is not that important but I told him you want that RM function at least, sometimes it sounds good, and sometimes playing movies through it is really nice. The manufacturers want us dead. They know how warm a vertical IC will get and the put the boost cap right near the heat sink. So this is not that conclusive but on the other POC somewhere I got part of a schematic of a Mitsubishi power supply that is. It has a connection in the feedback loop of a 5 volt or whatever that is made specifically to make the Vcc(ee, whatever) fluctuate to corrupt the data in the IC. Another nail in the coffin ? They sent out a bulletin that the customers were to be told where to download a file to a USB drive and boot the TV with it is themselves, cutting us completely out of the procedure. The manufacturers waged war on us, I took it that way. I figured I was a general. |
| Phil Allison <pallison49@gmail.com>: Mar 10 09:30PM -0800 jurb...@gmail.com wrote: ==================== > You ain't shitting. What I don't see is how they can go to all the trouble making counterfeits that actually work > but are like underrated for the job. ** That is very rarely what happens - mostly it is only re-inking. There are no *manufacturers* making counterfeit transistors. The game is to buy up something cheap and * relabel * it as something more expensive. It only needs to look about right - same package. No need to even get the polarity right or the general class of device. NPN or PNP, switching or linear, low or high voltage or current - all look the same in the same pak. Then there are factory rejects and damaged or old stock you can play merry hell with. Turn a 5 cent part into a $5 one in few seconds with a simple printing process. I even got some 400V pigtail electros once that were in fact used, removed from old CFLs, repacked and relabeled. ...... Phil |
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