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Electronics => Repair => Topic started by: MathWizard on April 19, 2021, 05:54:01 pm

Title: Damaged Siglent SPD3303X-E PSU ?
Post by: MathWizard on April 19, 2021, 05:54:01 pm
Hi the main 2 CH's are working fine, but today I went to use the 3rd CH, and I'm only reading 0.5VmilliVolt (not 0.5V) w/ probes on the O/P, for either 2.5/3.3/5V setting. It's on/off light works, and it's overload light is green for OK.

I barely use that CH as it's not current limited (or not settable by the user), so I can't say for sure when it was working last. I tried using that CH in a situation 2 weeks ago were it might have been damaged, or already broke, I figured my circuit wasn't working.

At worst I would have just in effect ran 5V into a 1N4001 for a few moments on my circuit. I certainly never smelled any smoke, or heard anything besides the relay's (I was using all 3 CH's)


No way is this thing under warranty, and ages ago, I hacked it to the 3303X version. So I have no problem opening it up.
Title: Re: Damaged Siglent SPD3303X-E PSU ?
Post by: tautech on April 20, 2021, 07:36:37 am
Not heard of any Ch3 issues with these.
Things to try:
Exercise the voltage selection switch.
Check the Lock isn't ON.

Service manual:
https://siglentna.com/wp-content/uploads/dlm_uploads/2019/08/SPD3000X-Series-Service-Manual.pdf
P46 is the HW troubleshooting section.

Do post your findings please so to provide help for others that might have similar problems.
Title: Re: Damaged Siglent SPD3303X-E PSU ?
Post by: MathWizard on April 20, 2021, 03:51:55 pm
Thanks, No it should be on. I can't really recall using ch3 after I hacked it but I guessing I tried after that. The rest of it seems to work great.

Looking at it w/ the DMM, when I turn it on I get a peak of 1.1mV that quickly decays, and on the scope, I can see that little raise. But I can't see any spikes or anything happening to show it's trying to build up a real voltage, w/ single shot on any time scale.

So I was just making a LM723 PSU and a L200 PSU, so I better finish them 1st before I open this 1. The L200 is about done, I'm just breadboarding the other 1.
Title: Re: Damaged Siglent SPD3303X-E PSU ?
Post by: tautech on April 26, 2021, 10:51:21 am
Well one we sold last year did this too !  :o

Some emails to factory tech support offered some test tips and info that there certainly is fuse for each channel.
Waiting on values for each of them.  :popcorn:

Please check the below test points:
1.  F301 fuse.  check it whether burnt down
2.  Check the TP4, The normal voltage is 11.2± 1.5V
3.  Check the TP3, voltage of Pin1,2 is about 3V;  and the Pin3,2 is about 15V.
 
Please be careful. Because the board has the high voltage. 


(https://www.eevblog.com/forum/repair/damaged-siglent-spd3303x-e-psu/?action=dlattach;attach=1214786)