Help diagnose blown input battery charger  - Page 1
Forum section: electronics / general

author: bigjoncoop
author_rank: Regular Contributor
timestamp: January 04, 2024, 02:54:44 pm
content: I just purchased a top of the line AIMS POWER 36v / 48v Battery Charger from eBay that was listed as "untested but brand new" for only $50!AIMS POWER: CON120AC3648VDCUnfortunately when I received it I noticed some small signs of use and that some of the case screws were stripped out! So I decided to open it up first to make sure all was well and I'm glad I did....The 120v mains input side has been blown up. I will post pictures below.The input fuse is completely burned up. Immediately next to that is a large thyrister and 2 large input filtering capacitors I believe, that are slightly blackened but may just shmoo from the blown fuse... Maybe.*** also I noticed on the output of the charger there is a black short circuit mark on the negative screw terminal, and the positive terminal screw is completely missing....So possibly the output was accidentally shorted together, but would that cause the input to burn like that?Other than that there is no noticeable damage anywhere else. All the other components look fine as well as the PCB.There's a large Bank of N-Channel mosfets, I'm going to start checking each one to make sure they're not blown...There is currently NO short on the input or on the or output.If anybody could please help with any advice on what I need to start checking, how to confirm it's safe to replace the input fuse and try to power it back up, etc...I appreciate your help! This is a $400 battery charger and if I could get it up and running that would be fantastic.

author: soldar
author_rank: Super Contributor
timestamp: January 04, 2024, 03:58:31 pm
content: How about you reject it and return it?

author: bdunham7
author_rank: Super Contributor
timestamp: January 04, 2024, 04:03:41 pm
content: I would jump the fuse and if it works, great. If not, eBay money-back guarantee for "not as described".That said, you really have to wonder what happened to that fuse...

author: bigjoncoop
author_rank: Regular Contributor
timestamp: January 08, 2024, 03:47:13 pm
content: Quote from: bdunham7 on January 04, 2024, 04:03:41 pmQuote from: soldar on January 04, 2024, 03:58:31 pmI can't really return it because it was sold as "untested"... granted I could really push the issue and probably get my money back.But for the price that I purchased it for I'd be crazy to return it instead of just fixing it. I bought it to resell most likely.So it's obvious it could be fixed probably less than I paid for it so let's say I'm all in and $100. It's worth $400

author: tom66
author_rank: Super Contributor
timestamp: January 08, 2024, 03:49:32 pm
content: Quote from: bdunham7 on January 04, 2024, 04:03:41 pmA fuse failure like that looks very aggressive, not just e.g. too many inrush cycles. I'd check for AC side shorts which can hide behind the bridge rectifier before applying power.

author: PlainName
author_rank: Super Contributor
timestamp: January 08, 2024, 05:52:25 pm
content: Quote from: bigjoncoop on January 08, 2024, 03:47:13 pmMeaningless. It was sold as new, and if you look at Ebay's terms then that is:QuoteWorst case, it would be 'opened', but since the vendor didn't test it that's obviously not the case.Additionally, this is also obviously used so not new. The only way the vendor could escape - if he listed as 'used' - would be to specify an actual fault or issue. They haven't since it is untested.Sorry, but the vendor saw you and, he hopes, many more like you coming a mile off. Don't dick with it, otherwise the vendor will claim YOU broke it. Just return as 'not as described' and 'not working'.

author: thm_w
author_rank: Super Contributor
timestamp: January 08, 2024, 10:15:43 pm
content: Looks like this is the listing:https://www.ebay.com/itm/395066872270As PlainName said, just return it. Unless you want to pay $50 for a non-working supply. If you do, could get a partial refund.