Search found 195 matches

by Tekhed66
Fri Feb 05, 2021 6:39 pm
Forum: HELP!
Topic: Recapping my M1 - PART 2
Replies: 30
Views: 6229

Re: Recapping my M1 - SOLVED

Hi buddy, try these steps 1. remove slider 2. connect/solder the 2 contacts in the green circle ( OUT 2 in schematics, should be Right channel) 3. connect/solder the 2 contacts in the red cycle.( OUT 1 in schematics, should be Left channel) if you choose to skip step 1 , set slider to full volume. ...
by Tekhed66
Mon Feb 01, 2021 1:17 pm
Forum: HELP!
Topic: Recapping my M1 - PART 2
Replies: 30
Views: 6229

Re: Recapping my M1 - PART 2

In order to bypass it you need to connect a wire from the Left channel input of the slider to left channel wiper. Sorry I have no pic about this. If you are unsure about it , connect a signal tracer or oscilloscope to the Left channel input of the slider and compare it to the right input of the sli...
by Tekhed66
Thu Jan 28, 2021 1:23 pm
Forum: HELP!
Topic: Recapping my M1 - PART 2
Replies: 30
Views: 6229

Re: Recapping my M1 - PART 2

I believe that it could be the volume slider. When assembling /disassembling , you put the unit upside/down and apply pressure to screw / unscrew. Due to the front panel shape of m1 , a lot of pressure is applied to the volume slider and it can get easily damaged. Before using oscilloscope or signa...
by Tekhed66
Wed Jan 27, 2021 3:03 pm
Forum: HELP!
Topic: Recapping my M1 - PART 2
Replies: 30
Views: 6229

Re: Recapping my M1 - PART 2

Edit : are you sure that the volume slider is working correctly ? could it be that the sliders left channel is bad? If you apply vertical pressure on the fader, does this have an effect on the volume of the L channel? Hi Yekuku Thanks for the info ... I have a friend who owns an oscilloscope so I'l...
by Tekhed66
Tue Jan 26, 2021 11:00 am
Forum: HELP!
Topic: Recapping my M1 - PART 2
Replies: 30
Views: 6229

Re: Recapping my M1 - PART 2

Could it be that a cable is not properly connected to the main board ? The PSU looked good, but we need to measure voltages with load in order to figure out whats going on. My guess is that the 5V line does not go to the mainboard or the 5V is down due to a short / failing component. Hi Yekuku Well...
by Tekhed66
Thu Jan 21, 2021 11:33 am
Forum: HELP!
Topic: Recapping my M1 - PART 2
Replies: 30
Views: 6229

Re: Recapping my M1 - PART 2

Could it be that a cable is not properly connected to the main board ? The PSU looked good, but we need to measure voltages with load in order to figure out whats going on. My guess is that the 5V line does not go to the mainboard or the 5V is down due to a short / failing component. I'm was hoping...
by Tekhed66
Thu Jan 21, 2021 8:48 am
Forum: HELP!
Topic: Recapping my M1 - PART 2
Replies: 30
Views: 6229

Re: Recapping my M1 - PART 2

In a situation like this , it is recommended to have the multimeter probes already in place before switching on . Instantly , switch on and take readings then power off and go to the next voltage rail. What you dont want to see is more than 6V on the 5V rail, this could be bad news for the digital ...
by Tekhed66
Tue Jan 19, 2021 12:13 pm
Forum: HELP!
Topic: Recapping my M1 - PART 2
Replies: 30
Views: 6229

Re: Recapping my M1 - PART 2

The voltages are a bit on the high side, but there is no load on the PSU , so the chances are that the PSU is ok. In order to be 100% sure , you have to add a load and measure the voltages again. According to my thread from more than a decade ago : I have disconnected the power supply from the main...
by Tekhed66
Tue Jan 19, 2021 9:53 am
Forum: HELP!
Topic: Recapping my M1 - PART 2
Replies: 30
Views: 6229

Re: Recapping my M1 - PART 2

Hmm, voltages might be ok since there is no load. You are measuring the 12v rail wrong. -12v : ii || 12V : || ii Please measure these again and let me know. Ha! ... stupid me... I measured the 12V pins the same as the 5V pins. OK - I've remeasured correctly (!?) and the new results are: 5V rail sho...
by Tekhed66
Fri Jan 15, 2021 1:01 pm
Forum: HELP!
Topic: Recapping my M1 - PART 2
Replies: 30
Views: 6229

Re: Recapping my M1 - PART 2

If the LCD stays dark then you are probably missing the 5v voltage rail , but we need to be sure about this. I would also check diode D8 and coil L5. Hi Yekuku I checked D8 and L5 as you suggested... my multimeter shows 000 when the continuity is 100% closed/circuit closed 1 when the continuity is ...
by Tekhed66
Sat Jan 09, 2021 9:57 am
Forum: HELP!
Topic: Recapping my M1 - PART 2
Replies: 30
Views: 6229

Re: Recapping my M1 - PART 2

Hi , unfortunately I dont see any cracks. The picture resolution is not great, but from what I see, I would reflow all worked solder joints. To continue troubleshooting you need to measure the 5v/12v/-12v voltages of the psu. If you are not comfortable with this , dont do it, wait for your friend t...
by Tekhed66
Sat Jan 09, 2021 4:01 am
Forum: HELP!
Topic: Recapping my M1 - PART 2
Replies: 30
Views: 6229

Re: Recapping my M1 - PART 2

Hi tekhed, the big central capacitor looks good , the 2 holes are for fitting different sizes of capacitors. The problem should be on the secondary side of the power supply, can you please upload a picture showing the back side of the whole pcb (especially the area that you have worked on)? In the ...
by Tekhed66
Thu Jan 07, 2021 8:28 pm
Forum: General Synthesizers
Topic: Sounds made easy : SR-JV80-04 and 08
Replies: 19
Views: 11306

Re: Roland XV-3080 loading sysex

I am working with my old XV3080 again and want to send a user bank to it with patches written for the (in)famous SR-JV-80-04 card vintage synth but my machine doesn't respond. I can send the midi but inside nothing happens. I have the files in a .mid format and I am thinking that exactly that might...
by Tekhed66
Thu Jan 07, 2021 2:44 am
Forum: HELP!
Topic: Recapping my M1 - PART 2
Replies: 30
Views: 6229

Re: Recapping my M1 - PART 2

I think that you might broke a pad while soldering / desoldering caps. Test pcb traces for continuity with the psu powered off. Yes this is what I was going to suggest also. There's a crack right where it says KLM-1269, and the bottom right corner of the PCB is cracked off as well. So a continuity ...
by Tekhed66
Tue Jan 05, 2021 11:07 pm
Forum: HELP!
Topic: Recapping my M1 - PART 2
Replies: 30
Views: 6229

Re: Recapping my M1 - PART 2

Hi buddy, first of all check the fuse. I have noted the pins in the picture. Good luck ! Hi Yekuku Thanks for the info on the 5V / 12V pins... definitely a job for when I'm back from work! I checked the fuse (first thing I did)... it's still OK (I was hoping it had blown if that makes sense). Any i...