Switching Power Supply SPS 1000 question

[Emetal]

There was smoke and bad smell, I have found burned and blown R11 and R12, dead D7 and bad Bridge Rectifier D5. After replacing everything I wanted to check with you more experienced guys is there anything else that should be checked and how, before I turn on the thing. For example is there a need to check the Relay K1 and HOW to do it?

[nickb]

Check T3 and T4 for shorts. If either is bad check all associated driver components i.e T1, T2, T5, T6, R1, R2, R28, R5, D24, R29, R7, D25 and IC1. When one of these FETs blow it often takes a bunch of other parts with it. Power up using a light bulb limiter.

PS: Also check diodes D6, D9, D14, D13, D16, D15. Disconnect the load before you power up if you can.

[Emetal]

OK the IGBT's T3 and T4 do have shorts between Collector and Emitter, i can not find 1MBK50D060S (600V, 50A, 200W) here in Belgrade, but the sales guy offered replacement IGBT: IRG4PC50W (600V, 55A, 200W) he says it is equivalent replacement? Anybody? Is that OK? I am attaching datasheets for both. Will the driver IC and other supporting elements be able to handle this?

[Emetal]

Here is even better match IRG4PC50UD Would this one be OK?

[nickb]

I think either will work.

Did you check all the other components listed? I should add C15 to the list but that would be a rare failure.

For the first test, remove R11 (or R12) to disable the power to the main switcher. You can then power up and check the auxiliary supply is working and producing voltage between IC1 pin 1 and 4. You can also check for proper switching waveforms (use an isolating transformer on the AC power in) on the gates of T3 and T4. If that looks OK then replace R11/R12 and power up with the light bulb limiter.

[Emetal]

nickb thank you for helping with this, I am not a pro I do not do this every day, just from time to time, your help means a lot. Now, here is the break down:

Components found to be faulty and replaced: R11, R12, D7, T3, T4, T1, T2. Also replaced IC1 just in case. (it's cheap)

Components found to be OK (checked out of the circuit): R5, R7, R1, R2, D25, R28, R29, D24, D13, D14, D15, D16, T5, T6, C15, D6, D9

All the soldering checked with the buzzer for continuity (I had problems with board traces here and there, so made shore everything is OK afterwards)

Now for those tests you mentioned, I do not have oscilloscope, I do not have isolated transformer, the only thing I can do is remove R11 or R12 and check the 1 and 4 Pins on the driver IC1. What should be there? 15,6 VDC?

I do have light bulb limiter. For the power up do I disconnect X4 (mixer power) and X6 (amp power)? Do I also disconnect X3 and X5?

[nickb]

It sounds like you've been pretty thorough and that bodes well.

A bulb limiter is easy to make. Just search for it.

On the gate voltages, first measure the supply voltage between pins 1 and 4 of IC1 ( R11 or R12 removed). The voltage measured between gate and emitter of each of IGBTs should be a little less than half of that but it's not a great test with a meter. If OK put R11/12 back in and try it out checking for the output voltages.

The problem with SMPS's is that if you've overlooked just one tiny failed component you can blow the whole thing up again and that gets demoralizing real quick.

[Emetal]

Well, we got half way through, this is the deal:

STEP 1
Power Supply on its own - bulb limiter lite's up, then Relay clicks on and bulb dims down, stays dimmed so I guess OK

STEP 2
Power Supply and FAN and MIXER - the whole mixing board lit's up nicely - bulb limiter lite's up, then Relay clicks on and bulb dims down, stays dimmed so I guess OK

Step 3
Adding HCA2400 connections X3,X5 and X6 BAD NEWS, bulb stays bright, bad smell from HCA2400, quickly turned off.

Checked Step 2 with only fan and mixer, everything OK again

SO I guess bad HCA2400. Should I then make a new thread for fixing HCA2400 to hear suggestions.. you can continue here too..

[nickb]

Well it's good progress - you crossed a big hurdle. I think a new thread is probably a good idea.

This a Berhinger Europower mixer, right?

[Emetal]

Yeah it's Europower PMP5000, I hate to even look at that HCA 2400 board, so much little printed parts.. I wish I could just buy that whole module, but I do not see it anywhere for sale... They glued every single connector I can't even remove the input connector from the mixer into the amp without braking printed electrolyte, the glue is all over those caps.

[nickb]

Call them and ask. There's no shame in outright replacement and it's sometimes a less expensive route. Might be a good time to update your profile with your location so others can chip in if they know the number for Behringer parts in your locality.