Ask HN: How often is test equipment the source of your errors?

I'm a technician at a large aerospace company. I work on systems with BOM costs in the 6 figures that sell for 7 figures. Despite this, our test equipment is horribly maintained. During testing, if we encounter a non-conformance, the immediate reaction from me or my co-workers is to suspect that it's a test software or hardware issue.

Be it the cables used, the test software, the test hardware itself, or the unreleased customer software that's loaded on the device to be tested, we have to rule out the equipment before we suspect that it's something wrong with the product. I'm just wondering if it is common in large companies to neglect preventative maintenance. Thank you.