# DC Power Supply - Flashing red lights

**URL:** <https://forum.sienci.com/t/dc-power-supply-flashing-red-lights/3787>\
**Category:** ❓ Something's Up\
**Created:** [September 30, 2021, 7:53pm UTC](https://forum.sienci.com/t/dc-power-supply-flashing-red-lights/3787 "2021-09-30T19:53:14Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![nor](https://forum.sienci.com/letter_avatar_proxy/v4/letter/n/a9a28c/32.png) [@nor](https://forum.sienci.com/u/nor)\
**Post date:** [September 30, 2021, 7:53pm UTC](https://forum.sienci.com/t/dc-power-supply-flashing-red-lights/3787/1 "2021-09-30T19:53:14Z")

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I lost power to my inputs. I can get the circuit board lights to flash on intermitently when I push on the green input switch. The lights also flash on and off when the on-off switch is toggled. Is the switch fried?

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**Author:** ![paullarson](https://forum.sienci.com/user_avatar/forum.sienci.com/paullarson/32/8543_2.png) [@paullarson](https://forum.sienci.com/u/paullarson)\
**Post date:** [October 1, 2021, 12:02am UTC](https://forum.sienci.com/t/dc-power-supply-flashing-red-lights/3787/2 "2021-10-01T00:02:37Z")

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Are you talking about the four (I think) bright red LEDs? Is you LM an older one, pre eStop? If so, the switch on the controller might be bad. You can wire across the switch to work around this problem.

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**Author:** ![gwilki](https://forum.sienci.com/user_avatar/forum.sienci.com/gwilki/32/366_2.png) [@gwilki](https://forum.sienci.com/u/gwilki)\
**Post date:** [October 1, 2021, 8:43pm UTC](https://forum.sienci.com/t/dc-power-supply-flashing-red-lights/3787/3 "2021-10-01T20:43:34Z")

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@nor Ron: I would bet that Paul has identified your problem.You can test to see if this is the problem by using an alligator clip lead.

 ![longmill switch pins](https://forum.sienci.com/uploads/default/original/2X/0/0a3e6bc1e07f1669323c128b9c42283bb2f1d2ef.jpeg)

I’m attaching a jpg of the underside of the long board. You can bridge those two tabs to bypass the switch. It will mean that you will need to use a power bar or some other means to turn off the controller.

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**Author:** ![nor](https://forum.sienci.com/letter_avatar_proxy/v4/letter/n/a9a28c/32.png) [@nor](https://forum.sienci.com/u/nor)\
**Post date:** [November 6, 2021, 12:34am UTC](https://forum.sienci.com/t/dc-power-supply-flashing-red-lights/3787/4 "2021-11-06T00:34:20Z")

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Thank you. All is well with the jumper on the switch. Ron