# Connect the Saleae probe means pull-down?
**URL:** https://discuss.saleae.com/t/connect-the-saleae-probe-means-pull-down/1568
**Category:** Uncategorized
**Created:** [April 29, 2022, 2:14am UTC](https://discuss.saleae.com/t/connect-the-saleae-probe-means-pull-down/1568 "2022-04-29T02:14:07Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@alex925chen](https://discuss.saleae.com/u/alex925chen)
#### Post date: [April 29, 2022, 2:14am UTC](https://discuss.saleae.com/t/connect-the-saleae-probe-means-pull-down/1568/1 "2022-04-29T02:14:07Z")
I had SPI issue, the waveform is good with other scope(LeCroy) but malfunction.
But when I connect the SCK with Saleae probe, then the function suddenly turn to PASS.
What’s the Saleae probe inside?
Is that meaning I connect SCK with pull-down?
Could anyone comment on this?
Thanks!
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### Author:  [@timreyes](https://discuss.saleae.com/u/timreyes)
#### Post date: [April 29, 2022, 11:30pm UTC](https://discuss.saleae.com/t/connect-the-saleae-probe-means-pull-down/1568/2 "2022-04-29T23:30:49Z")
@alex925chen Can you confirm which exact Saleae Logic model you own?
> **[How to Identify Each Saleae Device](https://support.saleae.com/faq/general-faq/identify-each-saleae-device)**
You can take a look at the datasheet for your specific device to get the input impedance values.
> **[Datasheets](https://support.saleae.com/datasheets-and-specifications/datasheets)**
It would also be good to know the following:
- How is your Saleae Logic connected to your DUT?
- How are your SPI signal traces laid out on your PCB?
- What is the input impedance of the LeCroy scope probes that you are using? It might be good to compare to ours to see what might be causing the difference.
- Does your DUT pass without any probes attached?