HIKVISION SMPS repair(12V,10A) - Page 1
Forum section: electronics / repair

author: khatus
author_rank: Regular Contributor
timestamp: October 15, 2025, 06:09:03 pm
content: This is an SMPS (12 Volt, 10 Ampere) from the company HIKVISION. Someone gave it to me for repair, but I don’t have much experience in this kind of work, and I’ve never fixed one before.The SMPS is making a “tick-tick” sound from the output side, and the green LED light on the output is blinking . When I checked the output voltage, I got around 5.1 volts instead of 12 volts.What could be the possible reason for this issue? And what are the step-by-step things I should check to troubleshoot it?If someone could explain the testing steps, that would be very helpful.https://www.youtube.com/shorts/zjDjp0_8ayg?feature=share

author: bombcat
author_rank: Contributor
timestamp: October 16, 2025, 02:03:12 am
content: Switching power supplies are very dangerous, with DC voltages exceeding 300V. If you no experience, it's best not repair it. (This phenomenon is called 'hiccup,' and there can be many possible causes, such as feedback optocoupler protection, or a short circuit at the back end, capacitor has failed，potentiometer，utc3843d...) （The output needs a load）utc3843dhttps://www.lcsc.com/datasheet/C576160.pdf

author: Sorama
author_rank: Frequent Contributor
timestamp: October 16, 2025, 05:35:14 am
content: As already said , you need to be aware of the high voltages, even when not powered ( big capacitor keeping their charge).Secondly, start to analyse the kind of switched power supply; is it with or without pfc, is their a standby voltage or not, what switching ic’s are used…Lookup the data sheet of that ic to understand its functionality.What is the voltage at that big cap when working and when powered off?Answer: I don’t see a pfc circuit and this ps is pretty basic.Ps: check the voltages of that optocoupler when powered on.What does the input doe and the same for the output: is there a hiccup too?

author: asis
author_rank: Frequent Contributor
timestamp: October 16, 2025, 06:09:37 am
content: Replace ECAP C3.

author: Poroit
author_rank: Frequent Contributor
timestamp: October 16, 2025, 07:50:05 am
content: G'day khatus,The attached could be of interest.

author: Psi
author_rank: Super Contributor
timestamp: October 16, 2025, 08:10:37 am
content: The "tick-tick" is the thing trying to start and then saying "Nope, i'm outta here" and then retrying a few 100's of millisconds later.It could be a short circuit on the output, but there's a few others things it could be too.If it was me I would try power up the output terminals with 12V using an external current limited lab powersupply (no mains power on unit) and check the current is basically zero, or a few 10's of mA. If it's trying to draw 300+mA and not even getting to 12V then something is shorted on the secondary side somewhere.But as others have said, there are dangers here, the primary side capacitors are potentially lethal and store a charge even after unplugging it

author: Audiorepair
author_rank: Frequent Contributor
timestamp: October 16, 2025, 08:11:52 am
content: There is a reasonable chance that it is either:C3 small green Electrolytic.D4 / D5 shorted.4 green Electrolytic output capacitors.If not it is a whole lot more complicated and you would need to learn SMPS.

author: Sorama
author_rank: Frequent Contributor
timestamp: October 16, 2025, 10:18:17 am
content: Quote from: Psi on October 16, 2025, 08:10:37 amYou forgot the switching ic.

author: Psi
author_rank: Super Contributor
timestamp: October 16, 2025, 10:46:51 am
content: Quote from: Sorama on October 16, 2025, 10:18:17 amIn what way?

author: Sorama
author_rank: Frequent Contributor
timestamp: October 16, 2025, 12:07:18 pm
content: Quote from: Psi on October 16, 2025, 10:46:51 amow, my mistake.I mentioned to quote@Audiorepair; he forgot to mention the ic.Sorry.

author: Audiorepair
author_rank: Frequent Contributor
timestamp: October 16, 2025, 12:19:44 pm
content: The switching IC is clicking.This usually, but not always, indicates it is working - starting then shutting itself down due to an external problem.

author: Sorama
author_rank: Frequent Contributor
timestamp: October 16, 2025, 12:46:32 pm
content: I don’t know of a switching ic that can make an audible sound like TS mentioned.There is no relay involved in this ic.

author: wraper
author_rank: Unknown
timestamp: October 16, 2025, 01:05:29 pm
content: 90% chance it's C3 dried out + a few % chance of shorted D4/D5 (as this is a single output supply, I do not think LED would blink if rectifier was shorted). Clicking is a sign of IC being good.

author: Psi
author_rank: Super Contributor
timestamp: October 16, 2025, 01:24:56 pm
content: Quote from: Sorama on October 16, 2025, 12:46:32 pmIt's the inductor/transformer actually emitting the clicking sound , but its the IC causing it by starting, detecting a fault and powering off, then retrying. The bursts of inrush current cause things to vibrate.