beautyofdecay_ Posted March 9, 2018 Report Share Posted March 9, 2018 (edited) In preparation for receiving my BLM16x4+TPD front panel next week I started installing my MBSEQ components (Wiba panel and TPD) into a 19" rack case. Until now I had this setup connected to my computer and upgraded to the latest version via MIOS Studio. This work perfectly fine. the sequencer and all LEDs, displays and TPD were fully functional. But, when I try to power the sequencer from an external PSU both displays light up and just display blocks on the top row. Nothing else happens. No LEDs, no reaction on button presses. TPD stays dead. I connected the external +5V to J2 and removed jumper J17. J15 is set to +5V and J18 is open. Power consumption is about 100 mA. The PSU can deliver 2A. I tried disconnecting everything but 1 display and that doesn't change anything. I have been reading through a lot of similar posts for the last hour but have not come across the same problem. There must be something I'm overlooking...? Edited March 10, 2018 by beautyofdecay_ Quote Link to comment Share on other sites More sharing options...
slo Posted March 10, 2018 Report Share Posted March 10, 2018 That's pretty strange because it looks like you are doing everything correctly, the only thing that does seem off is the power consumption seems low for a SEQV4, with the displays and all the boards hooked up it should draw a lot more power, so check connections and try another p/s is all I can say. Quote Link to comment Share on other sites More sharing options...
flyweight Posted March 10, 2018 Report Share Posted March 10, 2018 Hi Yes, According the manual a midi box should consume between 400 - 1000 ma, depending on the lcds or the type of leds. What power do your lcd's need. I see on the schematic that both 5 and 3.3 v are supported. Have a firm look at the core board schametic i will say. Cheers Tim Quote Link to comment Share on other sites More sharing options...
beautyofdecay_ Posted March 10, 2018 Author Report Share Posted March 10, 2018 (edited) Yes, that's what I think is so strange. My LCDs are 5V ones. The only thing different is that when my PC is not connected, the sequencer doesn't boot anymore. It's just as if it's somehow needs the PC connection for something...??? Here is a picture when connected to my PC. All is fine. And this is how it looks when powering the sequencer via external power. In this case I tried powering via USB but with an external USB power adapter (5V, 2.5A) with J17 closed. I get the same results as when using an external power source connected to J2 with J17 open. Thanks, Andre. Edited March 10, 2018 by beautyofdecay_ Quote Link to comment Share on other sites More sharing options...
goyousalukis Posted March 10, 2018 Report Share Posted March 10, 2018 A quick way to troubleshoot would be to unplug your LCD's and see if it boots all the way. You could tell since the LEDs should come on. If it does boot, then you know it has to do with the power consumption. If not, then it is something else. How are you connecting your external power? Are you connecting it to jumper 2, or using a USB micro cable to a wallwart? Quote Link to comment Share on other sites More sharing options...
flyweight Posted March 10, 2018 Report Share Posted March 10, 2018 I would try - only the displays and the coreboard - try adjusting the LCD bias. If I remember it correctly there is a trimpot for that on the coreboard. Do I see it correctly and does the Track position display not work as wel? If that is the case forget the LCD bias thing. Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted March 10, 2018 Report Share Posted March 10, 2018 Can you check the 5V rail, when you power it externally? 100mA is a too low current - a reason might simply be, that the PSU is damaged and not capable of delivering 2 Amps. That could cause a voltage drop to probably way below 4.5V and a low current reading. It is strange, that it does not work with an alternative external power source, though, but please measure the 5V rail voltage and report back. Many greets, Peter Quote Link to comment Share on other sites More sharing options...
beautyofdecay_ Posted March 10, 2018 Author Report Share Posted March 10, 2018 (edited) Thanks for your replies. I don't think it's a power supply issue. It looks like the mbseq firmware somehow doesn't boot if no PC is connected. The sequencer is connected through a powered USB hub to my PC. In this situation the sequencer works fine. When I disconnect the PC from the USB hub and leave the connections to the sequencer as is (so the mbseq is still powered via USB but not connected to the PC anymore), the sequencer will not boot. So it has to be something else. I know it sounds weird but it looks like the sequencer somehow boots its firmware from PC via USB...?? Is that even possible? Did I somehow mess up the firmware upload? For your information: I'm running v4.94b on an STM32F407G Discovery board model M8997D. Edited March 10, 2018 by beautyofdecay_ Quote Link to comment Share on other sites More sharing options...
beautyofdecay_ Posted March 10, 2018 Author Report Share Posted March 10, 2018 5 hours ago, goyousalukis said: A quick way to troubleshoot would be to unplug your LCD's and see if it boots all the way. You could tell since the LEDs should come on. If it does boot, then you know it has to do with the power consumption. If not, then it is something else. How are you connecting your external power? Are you connecting it to jumper 2, or using a USB micro cable to a wallwart? I tried both options and in both situation the sequencer will not boot. Quote Link to comment Share on other sites More sharing options...
latigid on Posted March 10, 2018 Report Share Posted March 10, 2018 Please update the Discovery board. If you are using the old firmware, the ST-LINK side holds the main F4 MCU in reset unless a USB mini cable is connected. 2 Quote Link to comment Share on other sites More sharing options...
beautyofdecay_ Posted March 11, 2018 Author Report Share Posted March 11, 2018 34 minutes ago, latigid on said: Please update the Discovery board. If you are using the old firmware, the ST-LINK side holds the main F4 MCU in reset unless a USB mini cable is connected. YES! I upgraded the Discovery board firmware and now the sequencer also boots on external power. Thanks a lot! Running the STM23F4 + Wiba panel + TPD consumes about 250mA. 1 Quote Link to comment Share on other sites More sharing options...
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