Hi

Hoping for some help please.

I opened my 2001 year XS to change a tactile switch (YES/INC) switch. When I did this I damaged the CN202 (30P) ribbon cable ends(ribbon from main board to display), which I had to try and strip back very carefully and took many tries to get right as on power up there was no display active and now no power to any switches which surprised me.

Finally I got the display to work ok and opening is ok on the display. I found a supplier for a replacement cable which is on its way. Problem is no the display is ok I am seeing no illumination on any switches and no switches on the “complete keyboard” are active.!!!

I checked the following:

1. Power supply main is ok to XS power board
2. I can read 5v and 12v output from the power board
3. I can measure 5v and 12v coming into the PCB left side where all jacks and midi connections are.
4. But I measure 0v from the connector out to switch panel PCB with sliders top left. I think this chains to the right side board with instrument switches.

Any guidance appreciated. Have I disconnected something that I missed, any power safety switch I missed, fuse other than main power fuse.....

i attach pic of startup sequence from service manual, I get to the display screen pic but power not initialized other than monitor.

Jim Donnachie

Click thumbnail to see full-size image

JimmyD1501 - 16 November 2020 04:32 AM

Hi

Hoping for some help please.

I can offer some assistance, but you’ll need to provide more detailed information. Since you have the XS Service Manual, I presume it’s in PDF form. If so, start with the Block Diagram on page 242 of the PDF. You’ll see that the boards have names such as “JKAN-JA”, “PNA”, etc. The connectors are also identified, such as one on the JKAN-JA board labeled “CN3-11P”, which is the third one on that board, having 11 pins. Please use the board and connector identifiers, including pin numbers, when describing what you’re measuring. That will make it possible to see what you’re doing without having to translate descriptions such as “the PCB left side where all jacks and midi connections are”.

Big hint…
Pointing with your mouse to certain items on the Block Diagram (such as connectors) and clicking will take you to detailed schematics, where you can see things such as connector pinout. There’s also interconnection information, such as “to PNA - CN1(Page 12 B-8)” - pointing/clicking on such will take you directly to those locations.

Try tracing the supply voltage issue again, using the above approach. If you get stuck, post again with board names, connectors/pins, etc.

Hi

Thanks for the reply and hope the attachment pictures makes it clearer from my work today.

I attached a screenshot of the results of my voltage measurements on each board main connectors. Starting at the power supply and moving out following white harness. I think these are the main power connections to each board.

As far as I can tell from the service manual the power voltage is ok to each lower board except that there is no output from any pin on the JKAN-JA 8P CN2 connector going out to the PNA Board.!! Picture of the connector CN2 attached.

Thanks in advance for help

Jim Donnachie

Click thumbnail to see full-size image

JimmyD1501 - 17 November 2020 03:33 AM

Hi

Thanks for the reply and hope the attachment pictures makes it clearer from my work today.

You’re welcome.

 

JimmyD1501 -

I attached a screenshot of the results of my voltage measurements on each board main connectors. Starting at the power supply and moving out following white harness. I think these are the main power connections to each board.

The table is nicely done, and helpful.

 

JimmyD1501 -

As far as I can tell from the service manual the power voltage is ok to each lower board except that there is no output from any pin on the JKAN-JA 8P CN2 connector going out to the PNA Board.!! Picture of the connector CN2 attached.

It’s normal not to find any DC voltage on JKAN-JA CN2. That’s connected to the Master Volume control slider on PNA, and only has signal (analog sound) voltages, and of course only when things are working normally.

DC comes from CN3-11P on the JKAN-JA board and is distributed to each of the CN1-11P connectors on the PNA, PNB-PN, and PNC boards. Please take measurements at those four connectors, and create a table similar to the one you already provided. That should help us get closer to the cause of the problem.

A general note:
Anyone working on the innards of a Motif should first be familiar with servicing electronic equipment, and aware of the pitfalls. One common error is to open the hinged top panel beyond 90 degrees relative to the bottom section. That can lead to significant damage to cables, etc. If you’re going to do your own servicing, please be careful, or you can make things worse.

Hi

Good and bad news today working on the motif.

The good news is that I found a problem with the voltage going to the PNC Board (details attached), the 5v was not getting to the PNC board but was ok on checking the connector from the top where I could get a reading.

This is the connector I removed many times while working on previous switch issues and understandably I could have tugged the wires out of place, I pushed the small wires down carefully to try and reseat them and it worked, I now get common readings across all boards on the CN1 11Pin stations.

The bad news is that the 30 Pin ribbon cable to the display finally gave up and i have no display again, I will have to wait for the new one I ordered to arrive to test again, which may be a few weeks as I am in the Philippines and part will come from China.

The unit still does not show any indication of powering up but without the display cable attached that may be normal, would that be correct.?

You are absolutely correct about opening the unit as this was part of my problem with the 30 Pin cable as the top slipped off a few times over the last months working on the switches. I now cable tie at three positions through the screw holes top to bottom and cable the right side top to bottom to stop it going right back (there is a rod for this in the service manual that I dont have)

Comments appreciated

Thanks for getting me this far, it really is appreciated.

Jim Donnachie

Click thumbnail to see full-size image

JimmyD1501 - 17 November 2020 09:57 PM

Hi

Good and bad news today working on the motif.

The good news is that I found a problem with the voltage going to the PNC Board (details attached), the 5v was not getting to the PNC board but was ok on checking the connector from the top where I could get a reading.

This is the connector I removed many times while working on previous switch issues and understandably I could have tugged the wires out of place, I pushed the small wires down carefully to try and reseat them and it worked, I now get common readings across all boards on the CN1 11Pin stations.

The bad news is that the 30 Pin ribbon cable to the display finally gave up and i have no display again, I will have to wait for the new one I ordered to arrive to test again, which may be a few weeks as I am in the Philippines and part will come from China.

The unit still does not show any indication of powering up but without the display cable attached that may be normal, would that be correct.?

As far as I know, LCD panel data flows only in one direction via the 30P cable, from DM CN824 to JKAN-LC CN202 (and then on to the LCD). Therefore, I wouldn’t expect a bad 30P cable connection to affect boot up.

The microcontrollers (µpd780031) on the PNA/PNB-PN/PNC boards communicate via the I2C E-bus. E-IC is the chip reset line, SDA is data, SCL is clock. (See http://www.google.com/search?q=E-bus+SDA+SCL+I2C to learn more about it). DC voltage measurements on those connector pins will not be very meaningful, since they’ll just be averages of the varying highs/lows of the data stream. However, at any one time I would expect any single I2C-related pin on all the boards to measure the same. Variations of E-IC/SDA/SCL from board to board that you show have me wondering if there are other connector/cable problems. Since DC voltage readings don’t help much with digital levels, I suggest that you disconnect the XS from power, and use an ohmmeter to verify that continuity exists for all the E-IC/SDA/SCL wiring (pins 1/3/5) from the JKAN-JA board to the three panel boards.

 

JimmyD1501 -

You are absolutely correct about opening the unit as this was part of my problem with the 30 Pin cable as the top slipped off a few times over the last months working on the switches. I now cable tie at three positions through the screw holes top to bottom and cable the right side top to bottom to stop it going right back (there is a rod for this in the service manual that I dont have)

That comment wasn’t really meant for yourself, but more to warn anyone else who might decide to get into an XS. On the other hand, if your LCD backlight doesn’t work, check the 2P connectors/cables to/from the JKAN-LC board at both ends.

 

JimmyD1501 -

Comments appreciated

Thanks for getting me this far, it really is appreciated.

Jim Donnachie

Hopefully we’ll get your XS working again.

Hi

Firstly thanks as always for your last reply, I can see for other concerns you have a real passion for the Motif and it’s great you have shared your experience with others such as myself

Had a chance this morning to do the conductivity test across the three boards and all was good across the 1,3 and 5 pins. I checked all other pins and all were ok.

Strange that still no illumination in the switches on the PCA board being there is power being supplied now.!!

I tried a voltage check on the PCA board at the “Master” switch to see if voltage was going through the board and it has 5v at the switch, this is the switch that on startup normally illuminates.!! I also check other switches on the same board and 3.5v to 5v was present on all I checked.

Please advise any next steps you think appropriate while I wait for the new flex ribbon 30 pin cable.?

Regards

Jim Donnachie

JimmyD1501 - 19 November 2020 01:01 AM

Hi

Firstly thanks as always for your last reply, I can see for other concerns you have a real passion for the Motif and it’s great you have shared your experience with others such as myself

Glad to do so.

 

JimmyD1501 -

Had a chance this morning to do the conductivity test across the three boards and all was good across the 1,3 and 5 pins. I checked all other pins and all were ok.

Good.

 

JimmyD1501 -

Strange that still no illumination in the switches on the PCA board being there is power being supplied now.!!

I tried a voltage check on the PCA board at the “Master” switch to see if voltage was going through the board and it has 5v at the switch, this is the switch that on startup normally illuminates.!! I also check other switches on the same board and 3.5v to 5v was present on all I checked.

Please advise any next steps you think appropriate while I wait for the new flex ribbon 30 pin cable.?

Regards

Jim Donnachie

The switch LEDs don’t normally light until the boot process is about done. Page 175 of the Service Manual gives some details of the boot sequence. If for some reason an I2C driver isn’t being activated, the boot can’t complete. However, we don’t know where in the sequence it’s stopping.

Is there any possibility that the 40P cable from DM CN615 to JKAN-JA CN5 might have been dislodged or damaged?

There are some checks that could be made with a scope, but without one it might be best to wait until the display is working. What the display shows might offer some further clues.

Hi
Appreciate the update comments.
I did disconnect the 40 pin cable that you referred to a number of times to check the components beneath the board. I rechecked it again today and it seems in good condition and well seated but I had also ordered a new one along with the display cable, will update you when they arrive and are fitted.
Might be a bit quiet for a week or two until these parts arrive but I am still on the case.
Thanks
Jim Donnachie

JimmyD1501 - 19 November 2020 10:23 PM

[...]I did disconnect the 40 pin cable that you referred to a number of times to check the components beneath the board. I rechecked it again today and it seems in good condition and well seated but I had also ordered a new one along with the display cable, will update you when they arrive and are fitted.[...]

OK.

The general problem is likely related to interrupted data flow.
I mentioned the 40 pin cable because I2C communication (among other things) from/to the processors on the DM board is via that cable.