Repair 30V Benchtop Power Supply No Voltage! PS-305D

30V Bench top Power Supply will no longer output any voltage. Follow along and see if I have it in me to fix this power supply.
Music is Hallow's Beach by Quincas Moreira

[@peterfahringer]

Thanks! I was going to throw out the power supply and checked KZbin first. 8 minutes later, my power supply is working again. 👍👍

[@thedriver02]

Great to hear!

[@frankpitochelli6786]

Not being critical, you should have a good solder station and use leaded solder with rosin core, it will help in your overall soldering technique.

[@gizmo1252000]

i watched your video this morning ,after my rapid 30v 2.5a bench power supply would,nt increase in voltage at all .0.00 on the display ,i was kind ticked off ,only owning it for 5 months ,yes it was a used unit ,but it worked .and itw as great for nickel plating . just checked the diode in question ,and hey presto . you where spot on .i,ve ordered the replaced diode ,and i felt it only fair to give my thanks for the information you gave ,in your video ,plus i learnt something ,regards sion .

[@williambrett517]

Many thanks, mine packed up 2 years ago and now it's working again. Same problem, easy fix.

[@pcrengnr1]

I love screwing the Chinese outta another sale and keeping E waste outta the E landfill. Good sleuthing. That output diode is there in case another voltage source like a battery gets connected backwards. Its value is chosen so that it will short protecting the PS output stage. So, huray for the design it functioned just as it should. It took a licking and kept on ticking. Just a minor part had to be replaced and the PS was back to work. A clue that was showing is that you had current of about 4A while the voltage was around 0.6V. The PS was still exhibiting current control and most likely still retained its voltage regulation if not for the output diode short. This repair; saved money, saved time, saved the E landfill and you learned something. A good day indeed.

[@wesley071177]

Hello from England. Yours was the first video I found when searching DC power supply repair. Shining a light through the board is genius and I'll be using that in future for single or double layer boards. Subscribed 👍

[@mrhalfstep]

Thanks so much for taking the time to make this video. I found the same problem with my bench supply using your video and have ordered enough replacements to repair it 10 times @ a cost of just $6.00. BTW, if you don't know, that diode is the reverse connection protection device. It saves the supply if you cross the + and - leads on a battery. That's why I bought 10. Pretty sure that's gonna happen again in the future. LOL

[@thedriver02]

Thanks!

[@marcomich88]

I have to thank you too. Same problem, same solution. Thanks!

[@simeonmihaylov6123]

Thank You. Great video. Thanks to you, I've managed to fix my APS 3005D. The diode on my power supply was on a slightly different place, but it was easy to be found.

[@peetre]

That should fix mine for the same reason. That was a diode for reverse voltage protection. you should use a solder sucker or copper wick to remove solder. You heated and tore the copper foil trace. A little practice with either will make you a pro!

[@roop5318]

Thank you for the video! my diode appeared to have some damage as well. I had the short circuit condition after connecting an 18v lithium ion battery in series rather than paralell! There was an FR304 diode that failed it's diode test. Removing it confirmed the short circuit was gone. I replaced it with a 1N4004 diode and it's working again. This is an even smaller diode so it should fail faster next time I... test thing :) will be waiting a few weeks for the FR304 to arrive.

[@robertmotion]

glad I stumbled across your video. I have a RD6018 60V/20A. unit won't power on. gotta figure out what's happening. i started off like you, seeing if problem is from display or power supply itself. using a 12V power supply, found out my display is great, no problems. now on to the power supply itself.... don't know how I'm gon fix it or at this point what im really looking for, but I'm confident I'll figure it out. and you're right, ain't much help online ....answer is always "just buy a next one" Thank for your video, sir. /bklyn👑

[@eyotub]

Grazie infinite, con il tuo video mi hai permesso di riparare il mio alimentatore.

[@jlev505]

Cleaning with acetone and flux would help with soldering. Good job on repairing the diode. A $1.00 part is much cheaper than a new power supply!

[@danielsmith7105]

You beauty! thank you. Same problem with mine.

[@mickymick11]

you just fixed my Power Supply thanks bud

[@thedriver02]

Right on man!

[@dlerraouf]

Great video. Thanks to you, I've fixed my MCH-305b power supply . Shorted diode IN540 Thank you.

[@propinch]

Great Video! It helped me to fix 3 of these gems!

[@patricioastorgajelvez1081]

Thanks for sharing!! Digging the music

[@richardanderson5424]

Thanks. I bought one of these cheaper ones but am trying to fix an older common one. Bit heavy with toroidal transformer and analogue meters current overproduction is always lit up like on yours. (Not asking you to try to troubleshoot it you understand.. Just letting you know about it) Thanks for tutorial. I should have known to try these techniques and hope I can find some damage or failed component it worked until I dropped it so probably pcb crack. Can’t find it yet but I highly suspect it. Had a near enough schematic for it (These type are all the same not sure of model but I think you’ll know it.) It’s one of those heavy black ones with small 12v abpnd 5v regulated dc o/p connections on as well as main DC o/p

[@fabriziocognigni4514]

Ho riparato il mio grazie a questo video. Grazie.

[@dirkjachimsky9401]

6:45 Where did you learn soldering? Near a blacksmith?

[@thedriver02]

Something like that more or less 🤣

[@ricardoc.8406]

thank you, your a life saver

[@thedriver02]

Awesome glad it helped!

[@joepublic2894]

I wanted to ask ,why didn't you show it puting out any amps.now the voltage worksbut at what amperage?Before it showed amps going to 4.00 something. just asking ,thanks for the video

[@eeplaylist2093]

Thanks very nice fix.

[@RandolphSonata]

Thank You Sir!!

[@Tudor356]

It's a diode, protection for inverse polarity

[@antresia.9723]

How did you! You use your soldering iron to desolder the wire without using tools.😕

[@andrewverran3498]

Hi m8 , great video , any chance you know how to disable the short circuit protection , or make it switchabl? PeaceFromOZ😊

[@antresia.9723]

My dc power supply is different than the one you have.i have to replaced the mosfet transistor on the voltage side just one

[@shoaibsiddiqui9188]

very informative video thanks.

[@davidprice2861]

Your irons not hot enough. Interesting fix tho. Thanks.

[@antresia.9723]

Hi, how did he -------- he use the soldering to desolder components using only a solder iron how ---------- he did not use other tools😕

[@K3vinK]

@@antresia.9723 heat and pull. Which is kinda clumsy. Think one of the pads got ruined.

[@leohobbleohobb3781]

yepp the diode on mine cracked to.But my powersupply have a 6 turn shunt also over where the diode connect,That smelled and looked to have been to hot 1 time i did a mistake. Second time The diode broke and shunt burned off.Have to make a new.Have another supply same model witch i can messure the shunt to make one that is correct.Hoped there was possible to buy spare parts to it since this model comes under many brand names like Korad. RND KA30-3005d etc,but have been hard to fint out where if at all.

[@djlukas99]

thank you

[@aljabrial-iraqi6245]

Thank you . I have a similar one in which the voltage reaches only 20 volts, what is the cause of the problem

[@gardyfaustin8707]

The diode in mine is a whole lot larger ... How do I know which diode to buy . Thanks

[@GregKeane]

I bought the PS-1502DD Bench Power Supply on facebook and it does not work, it blows the fuse each time. I think it takes a 1A fuse but I put a 5A and still blows, can you suggest whats happening.

[@georgejaxxin4957]

perfect, exactly what was wrong with mine...........

[@hameedsk-]

i hv same unit, which transformer is used in this unit, in my power supply is gone faulty i hv to replace it, and dont know about out put voltage and name of it. plz tell me more on this transformer.

[@iceberg789]

but how did it get reverse voltage ? were you trying to charge battery with this ?

[@syedhussainalishah8005]

I have same dc power supply but on its output, there is 50 volts coming . What should i check to solve the problem. Kindly suggest me

[@otheruser1541]

I have loadstar LP3005D(30V, 5A) dc supply, the problem is the voltage is only increasing up to 10.5V, I have replaced potentiometer & relays as well but still the same issue.. kindly help to repair

[@leohobbleohobb3781]

on mine the shunt and power diode broke.Similar cause

[@Snycer]

Переделывал этот ЛБП до 8А за 5мин kzbin.info/www/bejne/aqLXd2OPm7GSqqc