Search found 118 matches

by JHatzia
Tue Jan 10, 2017 7:14 pm
Forum: HELP!
Topic: replacing a korg poly 800 battery
Replies: 4
Views: 4536

Re: replacing a korg poly 800 battery

I have a Korg Poly 800 mk1 without the square solder lands for a back up battery. Do any mods exist for this version or am I doomed to always use C-cell batteries for saving all my patches while the unit is off?
by JHatzia
Tue Jan 10, 2017 6:53 pm
Forum: HELP!
Topic: JX-3P with Skipping Fader
Replies: 76
Views: 9381

Re: JX-3P with Skipping Fader

Hey sorry for the slow response on that Mooger5. I read those values and it seems like there is no skip in voltage. I was moving it as slowly as possibly and seeing the value increase incrementally. Even flexing the board seemed to keep this the same. A friend pointed out that my finger was touching...
by JHatzia
Wed Jan 04, 2017 3:45 am
Forum: HELP!
Topic: JX-3P with Skipping Fader
Replies: 76
Views: 9381

Re: JX-3P with Skipping Fader

So I think it's mislabeled in the service manual but POWER looks like it's labeled CN2 in the manual, but is actually CN5 on the board. The voltages read as follows -14.84V, 14.84V, 4.84V. Then to the slider 4.94V and finally to PIN 16 on the mux.. 4.94V. And finally, from the PSU the +5V reads 4.94...
by JHatzia
Tue Jan 03, 2017 6:45 pm
Forum: HELP!
Topic: JX-3P with Skipping Fader
Replies: 76
Views: 9381

Re: JX-3P with Skipping Fader

Hey, completely understandable to doubt my desoldering skills at this point. But I'd fairly good at it, using a Hakko iron with solder already on the tip, applying it to a point and promptly sucking out the solder with minimum time with the iron against the board. Just a recap of what I have done so...
by JHatzia
Tue Jan 03, 2017 3:16 am
Forum: HELP!
Topic: JX-3P with Skipping Fader
Replies: 76
Views: 9381

Re: JX-3P with Skipping Fader

Just replaced the resistor and still no dice, so that's out of the equation. Flexing the board near the resistor (R95) and underneath the sense slider still fixes the issue. I keep reading for 5V in other areas but almost universally get 4.94V on the panel board. Here is a picture I took to see if t...
by JHatzia
Mon Jan 02, 2017 9:02 am
Forum: HELP!
Topic: JX-3P with Skipping Fader
Replies: 76
Views: 9381

Re: JX-3P with Skipping Fader

Can you clarify "feeding 5v straight to the mux"? Which PIN on IC4 and would that be the 5v off the slider or the slider out pin? I just want to make sure I did it right.

As it stands now I'm going to replace the 10k resistor tomorrow. Flexing right underneath the area fixes the issue it appears.
by JHatzia
Mon Jan 02, 2017 7:33 am
Forum: HELP!
Topic: JX-3P with Skipping Fader
Replies: 76
Views: 9381

Re: JX-3P with Skipping Fader

I addressed all of these joints Mooger5, I'm fairly certain W76 and R95 don't have cracked joints at this point.
by JHatzia
Mon Jan 02, 2017 6:20 am
Forum: HELP!
Topic: JX-3P with Skipping Fader
Replies: 76
Views: 9381

Re: JX-3P with Skipping Fader

Thanks for the encouragement Rasputin! So, reading still, the fader itself is getting 4.93V along with all the other components it runs through. Is this still not enough? Even jumping the slider out straight to the mux input (IC4 PIN 14 correct?) the problem persists. Pushing directly underneath R95...
by JHatzia
Mon Jan 02, 2017 5:08 am
Forum: HELP!
Topic: JX-3P with Skipping Fader
Replies: 76
Views: 9381

Re: JX-3P with Skipping Fader

Mooger5, I did some more continuity tests with the unit both ON and OFF. All the immediate traces seem to be connected just fine. Now how far do I have to trace for continuity? There are some components like R41 that will connect with the +5VDC only while the unit is powered on. Since it's an interm...
by JHatzia
Sun Jan 01, 2017 12:19 am
Forum: HELP!
Topic: JX-3P with Skipping Fader
Replies: 76
Views: 9381

Re: JX-3P with Skipping Fader

Thanks again for all the guidance! So, indeed I was thinking the slider tab was the +5V. I went ahead and reflowed the W154 joints and wired a jumper from W154 and the +5V on the slider.. still no dice. Here's a better attached image. I believe there is just flux in there that needs to be cleaned wi...
by JHatzia
Sat Dec 31, 2016 12:00 pm
Forum: HELP!
Topic: JX-3P with Skipping Fader
Replies: 76
Views: 9381

Re: JX-3P with Skipping Fader

Haha, indeed that is cat hair or the fibers from a q tip cleaning with some IPA. I just tried jumping the 5V to W154 and it made the SENS slider not move at all. I took off the jumper and am back to where I was. So close!
by JHatzia
Sat Dec 31, 2016 10:43 am
Forum: HELP!
Topic: JX-3P with Skipping Fader
Replies: 76
Views: 9381

Re: JX-3P with Skipping Fader

I don't believe I have an extra resistor on hand, but I can go ahead and place an order for a replacement.. Unless Radioshack were to have one similar. I'm happy some progress has been made, me pushing on the PCB itself rules out a lot of other possibilities. My apologies for not doing so from the g...
by JHatzia
Sat Dec 31, 2016 10:10 am
Forum: HELP!
Topic: JX-3P with Skipping Fader
Replies: 76
Views: 9381

Re: JX-3P with Skipping Fader

Hmm, just gave it a go with a small piece of multi threaded wire, flipped it on and still the same issue. Possibly I have to let a burn in occur or am soldering to the wrong end of the resistor?
by JHatzia
Sat Dec 31, 2016 9:51 am
Forum: HELP!
Topic: JX-3P with Skipping Fader
Replies: 76
Views: 9381

Re: JX-3P with Skipping Fader

I have tried to resoldering the joints multiple times. To me it seems like theres a crack somewhere in the PCB itself, very small, but it's there. Thus when I press near the area I pointed to in this pic, 9-11 start behaving. I was thinking about trying a jumper wire like I marked in red. Does this ...
by JHatzia
Sat Dec 31, 2016 8:14 am
Forum: HELP!
Topic: JX-3P with Skipping Fader
Replies: 76
Views: 9381

Re: JX-3P with Skipping Fader

Well I made a break through! Sort of- I feel pretty stupid for not trying this from the get go but if I apply some pressure on the green side of the panel board with my finger, I can get 9-11 to start working. I'm pressing my finger right by the resistor and the main leg of the SENSE slider. When I ...