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TA7317P IC issues

T

TomFowler

New Member
Hi, I am having problems finding a replacement IC TA3717p for my relay protection circuit on a JVC amp
I have bought several new ones , non of them works correctly, power on and there is no delay on the relay clicking in with a pop out of the speakers
Does anyone have experience of how they modified the chip or circuit to get round this? I would be most grateful of any ideas
 
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How do you know it's the IC? Most of the time the delay is generated by a resistor-capacitor combination. Sometimes that capacitor will go bad and upset the timing. Can't tell for sure without seeing the schematic though.
 
I bought a couple off that auction site and they worked fine. Must of got lucky I guess. I do remember looking at all the pictures from different sellers and matched to the shape and printing to find best match to what I had and no one shipping from across the ocean either. I did just look and the same seller still has more.
 
I did a little looking around and the counterfeit issue seems to have been around for a while. Not surprising considering how long the chip has been out of production.

Not they show any available but we sometimes used this resource where I worked: https://www.rocelec.com/
 
TomFowler said:
TA3717p
Click to expand...
(sic - assuming TA7317P is what's wanted)

If a USA seller is convenient for you, look for the listing on ebay from seller ceitron. Steve's not an audio expert, but he doesn't knowingly sell bogus parts. You can order direct from ceitron.com if you prefer, but the shipping and handling fees are generally higher.

(Edit - fixed my own typo in the part number!)
 
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hamrules said:
I bought a couple off that auction site and they worked fine. Must of got lucky I guess. I do remember looking at all the pictures from different sellers and matched to the shape and printing to find best match to what I had and no one shipping from across the ocean either. I did just look and the same seller still has more.
Click to expand...
Thanks , is there any way you could indicate to me which seller that was?
Cheers
 
You can get an adapter to convert frim the inline package to a DIP package and use a more modern device.
 
Tom Fowler, I know this thread is a couple years old. However, I have just experienced the same thing with a replacement TA7317P which allows immediate audio at power on and off with pops both ways meaning there is not any protective function happening. Its fake. I bought qty 5ea TA7317P that looked the right part from a US seller on eBay but the shipping took so long I figured I was going to get junk and I did (I just requested a return/refund). At least the original failing part would delay some undetermined amount of time before coming on but then shortly shut back off. I could watch the voltage on pin 8 build up to around 1.3v, audio would come on but shortly, again, a random amount of time, the voltage would then quickly drain off and the audio shut off. I tried all the timing circuit components first with no change. Did you ever find a real part? Do you have another one or two that you'd sell me? Or maybe a source reference? So frustrating this counterfeit electronic parts situation out of China. Its not my first experience last time was from Amazon. None of the legit parts suppliers I know of have this part.
 
Interesting. I just got a bunch of'em from Mr. Ma (Aliexpress). Better build a test jig for it and test them. Will report back. My recent experiences with Mr. Ma have been good. Got lots of semiconductors, some were replicas but no counterfeits. Others (Microchip PIC controllers) were the real deal.
 
Sonofabitch. I have counterfeits too. Built a Q'n'D test jig to test them against a true Toshiba and they failed. These are not TA7317Ps. Dunno what they are instead, all the other speaker protector ICs have only 8 pins. There is an easy test to check if your device is a replica (or true Tosh) or a counterfeit: there should be a resistance of 1.0k between pins#1 & 4. Between pins #2 and 3 to 4 there should be antiparallel diodes. These are actually transistors but that doesn't matter here. My counterfeits behave differently though in that they don't switch on the relay at all. Attached a schematic with correct voltages, a table with the counterfeit voltages and some test jig porn. And my bag with the counterfeits.

Guess I'm too late to ask for a refund...
 

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Good to know. I will make your siple.tests.on the remainder I have to see if maybe there was a real one or two in the lot of 5 I bought without having to solder them in to find out. Thank you. Do you have a real one you would part with?
 
I only have two of which one is needed in a project. The other one for repairs. If my purchase from Mr. Ma is successful you could try that store. But of course you'll want to wait for my report first. Alternately you could try an add-on board with speaker protection. Your amp will work just fine without it but you don't want to risk your precious speakers... Building a discrete TA7317P replica (like those STK units) is also an option but will need a lot of designing. Using an alternative like UPC1237 is a lot of work because it isn't pin compatible.
 
Today got my ten ICs. As expected, they are maliciously mismarked 9-pin SIP devices. Counterfeits. They test different from the first batch I got:
IMGP3828_crop.jpg
They are laser-marked (bottom is the real Toshiba):
IMGP3824_crop.jpg

Again, not a clue what they actually are. I asked for a refund. This wasted a lot of precious time and I still don't have the right chips.
 
PE9ZZ said:
I asked for a refund
Click to expand...
And almost immediately got it. Full refund, no need to return the ICs. Which will detour directly into the trash. I am sure Mr. Ma knows damn well that counterfeits are being sold on his tat bazaar. It is real sad that people try to make money this way. It was only a few euros but it took hours to get it back.
 
Bought 5 from eBay seller ...Installed and lost all lights display off front panel of Technics SA-404 what is this indicating ??? Also when you are checking the output voltages with the chip out of unit...what is the input voltage and on which pin
???
 
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