Behringer xenyx1222fx power supply repair  - Page 1
Forum section: electronics / repair

author: gabri.peic
author_rank: Regular Contributor
timestamp: December 29, 2019, 09:41:36 pm
content: Hello. Can someone please help me with my behringer xenyx 1222fx mixer.So basically i just bought second hand behringer xenyx 1222fx few days ago and it worked perfectly and one time I went to turn it off and power supply blew up literally.I reached for the power switch and heard loud explosion and saw a really bright flash from vents. I opened it up and found out that power supply board has blown traces.I can't figure out why it happened right when I turned it off. My theory is that when i turned off the switch it arced and that small power surge caused it to blow up.As far as i can see the Top245yn is shorted,small smd resistor is blown,rectifier is shorted and traces blew of the board. What do you think should i replace top245yn and few suspicious components on the primary side and bridge few blown traces or just sell this mixer for parts and buy a new one. I bought it for around 120 dollars it is a shame that it only lasted few days in my hands ): if I have to replace whole power supply it is not worth it. Psu is hard to find and expensive. Please tell me your opinion. ThanksSorry for my bad English i am from Croatia .

author: andy3055
author_rank: Super Contributor
timestamp: December 29, 2019, 11:47:31 pm
content: It all depends on how much of damage there is on the PCB. Most parts may be available. For example the TO245yn(https://www.mouser.com/ProductDetail/Power-Integrations/TOP245YN?qs=ulE8k0yEMYZrs3kXPYBUZw%3D%3D&gclid=EAIaIQobChMIhIXs54Tc5gIVEtNkCh1GiwU-EAAYAyAAEgKFwvD_BwE)The schematic is available here:https://elektrotanya.com/behringer_xenyx_1222fx_sch.pdf/download.html#dlPage 12 has the Power supply diagram. You have to decide if you are up to it.

author: gabri.peic
author_rank: Regular Contributor
timestamp: December 30, 2019, 12:23:48 am
content: Well I am going to try to fix it. Only thing i can see wrong with it is that shorted ic, Fried r16 resistor and rectifier.Board doesn't have that much damage I cleaned it up and it only has one larger blown traces that is right at power input and one thin trace that leads to r16

author: gabri.peic
author_rank: Regular Contributor
timestamp: December 31, 2019, 01:40:31 am
content: Also what is best glue/silicone to use for securing the wires that i used to bridge blown traces.I am waiting for replacement components to come and than i will hope it works.

author: andy3055
author_rank: Super Contributor
timestamp: December 31, 2019, 02:31:07 am
content: If you use single strand wires, you don't need glue. If you have to use glue after that, use some super glue spots in a few places.

author: SeanB
author_rank: Super Contributor
timestamp: December 31, 2019, 09:48:43 am
content: With the new TOPswitch replace R10, R11,R12 and C10, C13 with new ones, and check C7 and R1. if the new TOPswitch blows then suspect D2 and the secondary side diodes and capacitors.C6, C9, C12, C16, C2, C4, C5, C18, C19 and C20 I would replace just as a routine, as they will likely be getting old.

author: gabri.peic
author_rank: Regular Contributor
timestamp: January 01, 2020, 12:03:13 am
content: Thank you for the suggestion. I already repaired it i ended up replacing few caps,resistors,top switch and rectifier and than it sort of worked but it was not giving enough voltage and than i replaced the Optocoupler and it worked perfectlyThank you everyone for suggestions and i hope this post will help someone else in the future.