Dead Play:5 need schematics or tips

Hello, thanks for the picture.

I have-it fixed finally but I do not know the cause. Here it is in words and pictures:

First, small cap (C27854) is not charging from the AC side, those are probably discharge resistors to the remaining capacity in the filtering caps. It’s another mechanism I could not figure out. The C27854 is providing power to the ICE2QS02 driver chip. It goes thru all those small diodes and caps on the edge of the board. The normal behavior on the voltage for C27854 is that is charging up to around 20V slowly and then ( some of those diodes and transistors do that) turns on the power on the ICE2QS02. 

Once the chip is starting the voltage is self sustaining to around 13 V, I do not understand from where, maybe from the fly back transformer winding itself. 

So for me the challenge was to produce the charging of the C27854 up to 20 to start up the IC. I did this by putting 2 390Kohm from the + on the big caps. I monitor the voltage and it’s ramping up slow, like a second or two. After it reaches 20V the IC starts and it self sustain to 13V. It’s 3 days already and still works! meaning there is no other fail. There was no problem in the fuse or rectifier, nothing burned. As you can see the LED turns on with the 2 resistors soldered. This is the story of this fix.

 

I have no power on pin 7 on ICE2QS02 and when i measure on C27854 it goes from 9 to 18 VDC in a 2-3 second loop, is this the same behaviour as you had?

My Play:5 working again. If nothing helps you can power it with an external adapter.

My setup: 

• A laptop power adapter (20V - 6A)
• DC-DC converter (24-12V)
• DC connector (female)

The power is enough for max volume and there is no problem.

Thanks for the advice.

My Play:5 working again. If nothing helps you can power it with an external adapter.

My setup: 

• A laptop power adapter (20V - 6A)
• DC-DC converter (24-12V)
• DC connector (female)

The power is enough for max volume and there is no problem.

Thanks for the advice.

 

 

You beat me to it by a few hours!  Nice job!

I just repaired mine too.  I ordered a 24V/4A power supply very cheap on AMazon… $18CAD https://www.amazon.ca/gp/product/B08NYHM4J9/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1 .  I chose this one because it was 250 grams, approximately 95 watts, and the size seemed like it would fit -inside- the case.

I had a few DC-DC converters on hand like this: https://www.amazon.ca/gp/product/B07Y88RTXJ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I was fortunately able to fit everything inside the case.  I piggybacked the 120V supply to the AC-DC supply from the existing socket, and connected my DC-DC converter at the triple inductor like I had suggested a week or so ago.  I opened the power supply case, removed the existing wires, and soldered it all in directly.  I had to trim the two bass reflex ports about an inch, and was able to position the brick just below those centered between the two mid speakers at the back of the case.  I wrapped the PS brick it in a sheet of foam to avoid vibration.  It’s a snug fit, but everything went together perfectly.  There is no vibration, and I can’t tell the sound difference between this and an unmodified speaker.

Hi,

I have a new problem with my play 5.

2 components were blown Q27507/Q27502.

2 components shorted, Q27509/27503.

I think the part numbers are 34N B1. What are these? Mosfet? Appreciate it if anyone can share the part numbers of that 4 components in yellow box. Thks!!

On my board, all 4 of those components are the same, and are labelled DMB B8.  That is a DMP3098L (P-CHANNEL ENHANCEMENT MODE MOSFET  https://www.alldatasheet.com/datasheet-pdf/pdf/405103/DIODES/DMP3098L.html?)

The really weird part though is that “34N” is a different device!  That’s an N-channel mosfet:  https://www.diodes.com/assets/Datasheets/ds31787.pdf

Good luck!

Thanks Tim. You are truly helpful. Looking thru the datasheet, the Q27509/Q27503 on my board is indeed 34N B1, same marking placement as well. I am guessing those 2 blown would be the same.

Looking at my board again, only Q27515/Q27504 are labeled as DMB AN.

The rest like Q27203/Q27205/Q27303/Q27205 are all 34N B1

Fingers cross, thanks.

I opened up another PLay:5.

The two on the right are 34n, and the two on the left are DMB.  When I read the first board, I had confirmation bias as I was expecting to see DMB, and I was looking through a bunch of glue residue.  Those are indeed 34N as well.

This actually makes a lot of sense -- there should be both N and P channel to drive the speaker.

Sorry I misled you.  I hope you see this before ordering parts!

Thanks Tim. I have not order the parts yet. 😀 will place an order for both 34N and DMB. Cheers!!

I just had a success fixing a dead play:5 so thought I’d share it.  The device would not boot up. When I measured the voltage driving the PWM chip, I found it was ramping slowly from 7-8V up to about 19V, then dropping back to 7-8V and repeating.  The frequency of this was about 3-4 seconds.

I found a 10 ohm resistor that was open (R27797).  I replaced it with another 10 ohm and the device now works.  I only had a much much larger wattage resistor, but it got the job done.  Images are attached.

I had some other dead boards with the exact same ramping of voltage.  Unfortunately when I checked them, none of them had the same failure.  Hopefully this can help someone else though!

SO… My success 2 days ago inspired me to have another look at the two other dead units that I have.

I found a common problem to both of them, and got both working!

I had looked at everything in the high voltage section of the power supply, and couldn’t find any bad components.  Despite this, the devices were both not working, and on closer inspection were resetting about once every 5 seconds… There was power ramping up, and just as it hit 20V in the driver power to the IC, it would fall back to 10V or so and start over. This is a problem that others have had on this forum (and in this thread).

I looked at the datasheet for the PWM (ICE2QS02G), and realized that I had not checked the feedback section of the circuit.  This is the bit on the ‘other side’ of the opto-isolator.  Most of this part of the circuit is buried in glue, but sure enough, when I checked the resistors there, both of my devices had bad resistors in the same spot!  The resistor in question is a very small surface mount, with the marking “68b”.  Looking in the EIA listings , this is a 4.99k resistor.  Both of my devices had open resistors.  I added 1/8 watt 4.7k resistors (I didn’t have 5k), and lo and behold both devices now work.

The lower value resistor did have the effect of making the device run at 13V/26V instead of 12V/24V.  I don’t see this as a problem, as there are several EH31 regulators on the board, and the only thing (I think) that would be driven directly by these voltages would be the actual audio amplifiers.  Those should be tolerant.