Altec lansing ATP3 Speakers dont work - Page 1
Forum section: electronics / repair

author: Astaldoath
author_rank: Contributor
timestamp: April 10, 2017, 09:58:01 pm
content: Ok its been a long time since i plugged em in, like 7 years, they quit working, i believe they no longer turned on (if i remember the power know and the red LED didnt light up)I took apart the subwoofer box that houses the PCB, i tested most of the resistors and capacitors on the PCB and the zener diodes they all seemed fine. There is no burning or anything on the PCB, Im not sure how to test the audio connectors, 1 is a 7 pin Din plug, kinda looks like a ps/2 port, and then 2 normal audio jacks. The subwoofer plugs in to a 120v outlet (USA here). Looks like there is a transformer or something mounted inside the box of the subwoofer. Im wondering if that could be bad. How could I test that, and is there anyway to test the CMOS chips on the PCB, and test the other items i circled on the first picture.I will put em back together and re test em to make sure exactly what is wrong, sorry i didnt do that first, wasnt thinking, was too excited to use my new multimeter lol.Also i havent been able to find any schematics this is the best thing i foundhttps://www.manualslib.com/manual/249412/Altec-Lansing-Atp3.html?page=4#manual

author: The Soulman
author_rank: Super Contributor
timestamp: April 10, 2017, 10:21:32 pm
content: The transformer could be bad, the windings should read a couple of ohms.First you could measure the resistance of the primary winding at the plug, if it reads something in the ohm range that side of the transformer and fuse is probably fine.The secondary side should read even lower, if not then that's busted.

author: Astaldoath
author_rank: Contributor
timestamp: April 10, 2017, 10:39:01 pm
content: ok, i think i can take it out of the box, i noticed screws it will make it easier to test, if its junk are the replaceable if i know the specs of it? You think it would be expensive?

author: The Soulman
author_rank: Super Contributor
timestamp: April 10, 2017, 10:54:06 pm
content: Don't think you should have to take it out of the box, to measure the primary winding just measure the resistance at the power plug.Does the otherside of the transformer hook up to j4 on the pcb?If so measure the resistance of the connector that is supposed to hook up to j4 to measure the secondary of the transformer.

author: Astaldoath
author_rank: Contributor
timestamp: April 11, 2017, 08:08:08 am
content: derp true true, im still somewhat new at the repair field but i figured i had nothing to lose with these and everything to gain if i can fix em.

author: Astaldoath
author_rank: Contributor
timestamp: April 11, 2017, 10:30:34 am
content: Resistance at Plug 13.33ish ohms, at the j4 its 0.26 ohms (measured it over and over, made sure it was stable ect...)Sound right? Or does something sound wrong there if not its time to check out my switch on my main speaker.

author: Astaldoath
author_rank: Contributor
timestamp: April 11, 2017, 09:08:09 pm
content: It works lol, the one jack not the middle or the green but the brownish small one is loose, it could use being swapped out i think but it works fine if i dont push that plug in the whole way Awesome!