Siglent SPD4306X Quality - Page 1
Forum section: electronics / testgear

author: aarons
author_rank: Regular Contributor
timestamp: December 03, 2024, 08:46:40 pm
content: I recently got a siglent SPD4306x to replace a SPD3303 which started randomly turning it's outputs off. I also needed the higher current outputs.I've been quite happy with it, and it definitely seemed higher quality than the 3303. Earlier today I noticed a bothersome tone in my lab which I traced to the fan on the supply. I figured I'd replace the fan with a noctua fan to solve that problem (fan is ordered, should be an easy job.)However the first thing I noticed upon opening this supply I thought would be interest to the eevblog community.Everything else looks pretty good. There isn't even any Siglent Rust, but the fact that someone screwed this down and thought this looked fine to ship does make me worry. I slid 2 small washers in there to reduce that bend. I think that standoff might just be a tiny bit shorter than the others, but I haven't completely disassembled the unit to verify that.

author: tautech
author_rank: Super Contributor
timestamp: December 03, 2024, 08:53:41 pm
content: Will report incorrect standoff has been used.Welcome to the forum.You can hear the fan at full load in a very recent Defpom vid in the SPD4000X thread:https://www.eevblog.com/forum/testgear/new-siglent-spd4000x-series-power-supply/msg5734885/#msg5734885Expecting a Defpom teardown soon....

author: Martin72
author_rank: Super Contributor
timestamp: December 03, 2024, 09:07:32 pm
content: Ouch,Especially with SMD assemblies, such mechanical tension is very unwelcome.Hopefully just a “Monday device”.

author: aarons
author_rank: Regular Contributor
timestamp: December 03, 2024, 09:14:50 pm
content: The noise I was noticing wasn't normal fan noise. It was more like some sort of resonance that ended up sounding like a slight tone in the 1000-1200Hz range, and it was happening at the idle/no-load fan speed. Not a big deal, and overall this 4306X is a huge upgrade over the 3303 in every way.

author: tautech
author_rank: Super Contributor
timestamp: December 03, 2024, 09:23:02 pm
content: Quote from: aarons on December 03, 2024, 08:46:40 pmWhich exact model ?C, X-E or X ?The restart issue is a known failure of a 2A bridge on the Control PCB and a fairly simple fix.You can find several posts about various solutions.

author: aarons
author_rank: Regular Contributor
timestamp: December 03, 2024, 10:19:35 pm
content: Quote from: tautech on December 03, 2024, 09:23:02 pmIt is a SPD3303X-E. I'll take a look through the posts for the fix. If I can make it reliable again, I can use it in my office. Thanks!

author: J-R
author_rank: Super Contributor
timestamp: December 03, 2024, 10:39:28 pm
content: Surely the solution is to get a warranty replacement?

author: aarons
author_rank: Regular Contributor
timestamp: December 03, 2024, 10:50:43 pm
content: Quote from: J-R on December 03, 2024, 10:39:28 pmI got it in 2020, so it was out of warranty and they wanted something like $300 to repair it. They also offered a discount toward a replacement, but only if I replaced it with the same model, which I didn't want.

author: tautech
author_rank: Super Contributor
timestamp: December 03, 2024, 10:56:00 pm
content: Quote from: aarons on December 03, 2024, 10:19:35 pmEarly units were very reliable but later we ran into the tiny circular 2A bridges failing.Latest units have had a redesign and an uprated inline bridge is now used.All you need to know is in this thread:https://www.eevblog.com/forum/repair/siglent-spd3303x-e-reboot-problem/

author: J-R
author_rank: Super Contributor
timestamp: December 03, 2024, 11:01:53 pm
content: Oh? I thought the SPD4000 series just came out last year.

author: aarons
author_rank: Regular Contributor
timestamp: December 03, 2024, 11:12:11 pm
content: Quote from: J-R on December 03, 2024, 11:01:53 pmI got the SPD3303X-E, which had developed the random output shutting off problem, in 2020. After Siglent support told me it was out of warranty and would cost $300 or something like that to repair, I bought the SPD4306X to replace it. That was in 2024. The 4306 is the one with the fan noise and bent PCB, but since it's working fine, I'm not looking to try to replace it at this point.

author: tautech
author_rank: Super Contributor
timestamp: December 03, 2024, 11:51:58 pm
content: Quote from: J-R on December 03, 2024, 11:01:53 pmJune 28 2024https://www.eevblog.com/forum/testgear/new-siglent-spd4000x-series-power-supply/msg5556437/#msg5556437

author: J-R
author_rank: Super Contributor
timestamp: December 03, 2024, 11:56:15 pm
content: Well, I'm going to call it a 2023 product:

author: tautech
author_rank: Super Contributor
timestamp: December 03, 2024, 11:58:25 pm
content: Quote from: J-R on December 03, 2024, 11:56:15 pmSure but not for the western markets.

author: TheDefpom
author_rank: Frequent Contributor
timestamp: December 04, 2024, 04:44:09 am
content: I edited the 2nd part of the review this afternoon which has the teardown in it, mine is fine the standoff is the correct size.Makes me wonder if yours is a very early unit, mine had a fan above the transformer too which yours appears to not have installed ?

author: aarons
author_rank: Regular Contributor
timestamp: December 04, 2024, 05:00:14 am
content: Yeah, mine just has a single fan at the back. I ordered mine from Siglent in September, so not that long ago. I assume there was just a random shorter standoff in the bin of standoffs or something like that.

author: aarons
author_rank: Regular Contributor
timestamp: December 05, 2024, 06:24:21 pm
content: Upon further examination of the fan in this supply, it appears it is a non-standard 4-wire fan. The additional 2 wires are hooked up to two thermistors in parallel, one on each side of the heatsink. The fan speed control apparently is happening inside the fan itself, so replacing this fan won't work unless I want one that is constantly running at full speed.It's an odd design. The fan power comes from the front panel as a 4 wire connector that ls the same JST XH as the fan itself, but those 4 wires are +14, +14, GND, GND, which is then regulated to 12 on the rear board for the fan.Anyway, now I'm trying to see if I can source a replacement fan from Siglent or D-Fan (the manufacturer of the fan) since I think it's a customized part.

author: BILLPOD
author_rank: Frequent Contributor
timestamp: December 06, 2024, 06:44:19 pm
content: Good Morning Aarons,... I figured I'd replace the fan with a noctua fan to solve that problem (fan is ordered, should be an easy job.)So didn't the Noctua fan work, since you now want a Siglent OEM fan

author: aarons
author_rank: Regular Contributor
timestamp: December 06, 2024, 08:14:46 pm
content: Quote from: BILLPOD on December 06, 2024, 06:44:19 pmThat's right. I saw a 4-wire fan and assumed it was standard, but it is not.

author: KungFuJosh
author_rank: Super Contributor
timestamp: December 06, 2024, 08:37:06 pm
content: Quote from: aarons on December 06, 2024, 08:14:46 pmCan you share some photos of the stock fan and the PCB connector?Thanks,Josh

author: aarons
author_rank: Regular Contributor
timestamp: December 07, 2024, 02:13:50 am
content: Well I removed the connector housing from the stock fan, but it was a JST XHP-4. Here is a picture of the fan, and also a bit of the fan PCB, where you can see the 3rd and 4th wire are connected to pads labelled TR- and TR+. Those signals are the two sides of two thermistors in parallel.

author: KungFuJosh
author_rank: Super Contributor
timestamp: December 07, 2024, 02:41:37 am
content: Quote from: aarons on December 07, 2024, 02:13:50 amThat sounds like pretty common 4-wire fan setup? I don't know those circuits well, but I would guess that if anything isn't standard, it would be the order of the wire connections. I wouldn't expect a manufacturer to reinvent a basic PWM fan.

author: aarons
author_rank: Regular Contributor
timestamp: December 07, 2024, 04:00:29 am
content: The standard 4-wire fans has a tachometer signal output and a PWM signal input.

author: KungFuJosh
author_rank: Super Contributor
timestamp: December 07, 2024, 04:34:00 am
content: There's no PWM signal coming from the PSU PCB? Is it really just 2 positive and 2 ground wires? That's really odd.Have you tested the fan separately from the 4306X?

author: aarons
author_rank: Regular Contributor
timestamp: December 07, 2024, 05:05:46 am
content: I did hook up the original fan to a 12V supply and tried giving it PWM on those extra pins but it didn't do anything. Thats when I peeled back the sticker and saw the silkscreen. I suspect I damaged the speed control logic in it because now it only runs full speed, even with a 250k pot across those two terminals.