[Techtoolslist] WANTED : in-circuit IC tester

[Fabrizio Vasile]

Hi Andrew.No, I know very well there is no equipment which can test TTL
in-circuit absolutely .
But , I meant, something that can point you in the right direction testing
in-circuit logic functions and not comparing like the HP 10529A
I think I'll get a B&K Precision 560 IC tester after trying to find an ABI
Boardmaster 4000 at a reasonable price with no success.
Then, if  these in-circuit tester existe then they mean  they are useful in
some way, don't you think?I presume you didn't spend a lot of money into
the ABI Boardmaster 4000 to keep it as an ornament..:)


2013/7/31 Andrew Welburn <andy at andysarcade.net>


>  As i've mentioned before, i think that you believe there is equipment

>  out there that can give you a 100% accurate pass/go test on IC's. It

> doesn't exist.

>

> Regarding the 10529A:

>

>  If an input node is tied to ground/5v because of an internal short, then

> the comparison with a known-good IC will not show up any fault in the

> 10529. Its rare to find, but does happen.

>

>  The comparator is just that, it presents the same inputs to a known-good

> ic that the ic under test has. The outputs are compared, any differences

> show up. Failure modes of IC's can be varied, and a comparison method

> cannot find every single failure type in the same way that node stimulation

> can't either.

>

>  The 10529A is by far, the best all-round tool you can own, laborious

> though it is to use the ZIF socket to swap IC's and change pin assignments.

> You have to remember to power-cycle the unit-under-test for counters and

> flip-flops so that you get the same power-on states, otherwise your

> comparisons will be wrong.

>

>  I'm talking from 13 years experience of arcade pcb repairing here, i also

> own an ABI Boardmaster 4000, amongst other equipment for in-circuit testing.

>

>  If you have written off the 10529A as no good then you stand no chance

> using any of the other pieces of equipment to good effect. You need to

> understand failures and how they can manifest themselves first.

>

>  The holy grail of a pass/go system you seek is not within reach.

>

>

> Andrew Welburn

> http://www.andys-arcade.com

>

>

> On 30/07/2013 21:07, Fabrizio Vasile wrote:

>

>> Yes, using the HP 10529A I had several times good IC showed as bad

>> (especially counters, flip-flop) but, most terrible thing,  a couple of

>> times I had also bad IC showed as good!

>> ----- Original Message ----- From: "JJ" <rugd2go at comcast.net>

>> To: "Technical Tools Mail List" <techtoolslist at flippers.com>

>> Sent: Tuesday, July 30, 2013 9:59 PM

>> Subject: Re: [Techtoolslist] WANTED : in-circuit IC tester

>>

>>

>>  Has anyone had good luck with the HP10529 ?  I seem to get a lot of

>>> false ic failures during tests.  Have you seen the HP ever show a

>>> failed IC test good?

>>>

>>> Justin

>>>

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