Namaste Nagaraj,
In my opinion, the condition for the test is that it should be continuous and any significant break in the test which allows for the parts under test to 'normalize' will invalidate the test result. 
As its a customer qualification if I was themI would have reservations about how reliable the product performed given such a break. 
Personally I would scrap the samples and repeat the test with fresh product. 
RegardsColin


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On Sunday, December 13, 2015, 4:59 pm, Nagaraj U <[log in to unmask]> wrote:

Hi All,

We are manufacturers of bare PCBs.

We were conducting temperature cycling test as per
Condition B of JESD22-A104D (-55°C to +125°C). The
test requirement was for 500 cycles. This testing
was a part of qualification of PCBs for one of our
customer.

We have loaded a set of 4 bare PCBs and 4 assembled PCBs
(not powered on - loaded in passive mode after assembly)
in the thermal cycling chamber.

Now, 350 cycles are completed, but the thermal
cycling chamber has stopped due to some issue with
the thermal cycling equipment.

Now my question......... can the testing be continued
for another 150 cycles to complete 500 cycles OR
should the whole exercise be started from fabrication
of fresh PCBs, Assembly and do the temperature
cycling all over again.

OR, is there any standards which I could refer to
handle this situation.

Thanks in advance for your valuable inputs.

Best Regards,
U.Nagaraj
MICROPACK LIMITED,
Bangalore, INDIA.
Kindly note: Our domain name has changed to micropack.in from micro-pack.com, please update my email-id in your address book with the new domain name - micropack.in

[Logo]<http://www.micropack.in>

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