Another fake seller on ebay

Thread Starter

Robin Mitchell

Joined Oct 25, 2009
821
Hi all,

As a friendly reminder for those in the UK:

Amigacity
Mc_Manager http://www.ebay.com/usr/mc_manager?_trksid=p2047675.l2559

These two sellers sold me fake 4013 ICs. The first one was an import from china but the second one was also chinese but stocked in britain! So I am getting my money back on all those items.

Dont purchase ICs from these sellers as they may not work.
 

paulktreg

Joined Jun 2, 2008
768
Mc_Manager has been a member for a couple of years with 99.9% positive feedback on 20,000+ transactions.

You don't get statistics like that by deliberately selling fakes?
 

Thread Starter

Robin Mitchell

Joined Oct 25, 2009
821
I determined that they where fakes in the same way I determined the other chips. But here is a list of my findings:
  • Official 4013 chips can be configured as toggles. These do not work when configured as a toggle
  • Font is wrong on IC
  • Logo is wrong on IC
  • Chips explode (no joke), beyond 8V. These are rated to 15V
  • Epoxy is the wrong colour
I have purchased a number of items from mc_manager for a while now and have noticed that they are all re-stocks from china. Someone ships them in bulk and redistributes them here. They have good stats because I imagine most of their parts are not ICs and the ICs they do sell will be fake but may be functional. It might turn out that fake 4013 chips cannot be used in toggle mode where /Q is connected to the data input and the clock like is pulsed.

It specifically says in ALL the 4013 datasheets that they are ideal for counters, ripples and toggles!
Im just trying to give people some warning when purchasing from ebay, even "UK Suppliers"

I have now purchased some ST parts which I hope are the genuine article. TI parts are too expensive :(
 

Lestraveled

Joined May 19, 2014
1,943
Counterfeit parts are always a possibility nowadays unless you buy from the major suppliers, (Newark, Digi-Key, Etc). If you are going to push a part to its maximum spec, you would be foolish to buy unknown parts. But if you are a student/experimenter, on a low budget, buying cheap, you will have to expect to get some stinkers or some fakes occasionally. Just make sure the seller has a good return policy.
 

Thread Starter

Robin Mitchell

Joined Oct 25, 2009
821
@Lestraveled

I am on a budget :( which is why I have not be purchasing the official chips. And I appreciate that cheap chips wont be official parts but I expect it to at least have the same function.

Ummm....the 4013 doen't have a toggle function, IIRC. Unless you mean with Qbar tied to D.
Yes that is what I did but realise that the datasheet for the 4013 specifically states that it CAN be configured as a toggle and will function correctly. If it never mentioned this I would not be getting a refund ;)
 

Thread Starter

Robin Mitchell

Joined Oct 25, 2009
821
What I want to do out of interest is try to find out why they dont work. If they work in other configurations why is it when configured as a toggle they simply do not work. Is it that their inputs are not true CMOS and therefore require a substantial drive current to toggle or does connecting the /Q to D cause feedback issues? I am really tempted to investigate and make a video on it!

Why do they start to work below 3V (not reliably and only a few), and why do they explode above 8V?

I smell a 7400 series part in-place of a 4000 series....o_O
 

Lestraveled

Joined May 19, 2014
1,943
I am on a budget :( which is why I have not be purchasing the official chips. And I appreciate that cheap chips wont be official parts but I expect it to at least have the same function.......
Of course, that is what I mean. If they don't work, send them back. A part that does not function within the normal voltage range is definitely grounds for a return.


As to the 4013 toggle issue:
--From the ST data sheet:
"It can also be used for counter and toggle applications by connecting Q output to the data input."
 

Thread Starter

Robin Mitchell

Joined Oct 25, 2009
821
Yeah and that is what my configuration has which it does not work.

No promises but I am planning to make a video about this. Specifically showing some electrical tests to see what may be the cause of the problem!
 

Thread Starter

Robin Mitchell

Joined Oct 25, 2009
821
And you did appropriately tie the unused inputs to Vdd or Vss, yes?
Yes....Yes I did that. Done electronics for 8 years, I did that. Trust me. That was the first thing I did. I was also the first thing I checked.

I reckon it has something to do with the actual fabrication and I have a gut feeling that it has to do with the power supply voltage. It half works at very low voltages (less than 3V), which makes me think that the voltage is breaking down a junction somewhere. Here s something interesting, if the latch is off (q = 0), then it will toggle on but it will never switch back off.
 

paulktreg

Joined Jun 2, 2008
768
You obviously contacted the sellers and they have refunded?

Then I must ask are they still offering these products for sale and getting negative feedback?
 

Thread Starter

Robin Mitchell

Joined Oct 25, 2009
821
First seller has not refunded and second has arranged for a return. They will still offer the products because most buyers they have will not be buying that chip and even if they do I would imagine that the toggle arrangement is not used often. Just because they continue to sell does not mean they are not fake. I will be making a formal complaint to ebay about this soon.
 

dannyf

Joined Sep 13, 2015
2,196
If they work in other configurations why is it when configured as a toggle they simply do not work.
wiring issues? operator errors? ...

If you don't tell people how you configured it as toggle, others can never help you figure it out and you will forever be in the dark.
 

Thread Starter

Robin Mitchell

Joined Oct 25, 2009
821
@dannyf.

Look at the forum post I made ZBM - Z80 based computer. The schematics can be found there. Also, I know that they don't function correctly because I just replaced all the chips with authentic parts and it works perfectly.

I will be getting a test circuit made at some point but to be honest I have given up with this mini obsession for now. Need to focus on making the motherboard ;)
 
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