PC-1 Sustainer problem

[Mesaboog]

Recently I have noticed that when I turn on the sustainer in my PC-1 in regular sustain mode, it sounds like the tone knob is rolled back all the way. Huge difference between the off and on tone. Almost unusable now. Has anyone else experienced this here?

In this mode, the tone pot is having no effect. This isn't normal is it?

Any suggestions on troubleshooting this?

Thanks,

Scott

[rjohnstone]

Sounds like a low voltage issue.
Check batteries.
If they're ok, chances are the board is dying.
They don't last forever.

[Chief_CrazyTalk]

Oh damn, that "woman tone". What could be worse? Good luck fixing it dude! Do what I do at work...start swapping boards.

Or you could poke around the board. A light and magnifier will help. I'm thinking bad or broken solder joints, and broken or cracked resistors/caps if they used surface mount components.

[Axegrinder87]

In my years of experience as a lead SMT, I've never seen surface mount parts crack or break. But on that note, the only work I've ever dealt with was my own.

Broken solder joints sound probable though, especially in surface mount. Most overseas companies use inferior solder paste that doesn't hold up well with surface mount parts. The reason surface mount is more prone to breakage is because of the minimal amount of solder, and the shape of the joint. I'm gonna assume that given the assumed size of the board, they may have used 0603 sized parts, which take a bit more finesse to mount than the industry standard 0805.

[Mesaboog]

Thanks guys for the replies. Unfortunately, I have not made much progress in identifying my problem. I have looked, but have found no loose connections in the control cavity. The batteries are replaced and new. I am getting a strong sustain and octave harmonic sustain as well, so the unit IS functioning. However, the red light is not flashing at all when I insert the guitar jack. The main and most problematic symptom I am having is when I switch the sustainer on, I get a tone suck. Like a towel over the speaker, or tone knob rolled way back.

Important note: At one point about a year ago, 2 of the leads on the battery box had broken off and needed to be resoldered, which I did, but may not have been with electrical solder, just what I had in my tool kit (DOH...OK flame away). Could this be the issue? If so, should I try again with electrical solder on bare section of the battery contact? Also, the wires/leads into the battery compartment look like they have been a bit crimped (tight squeeze in there)...should I replace these with fresh wire?

Any other suggestions on determining whether this is a connection voltage issue vs. a bad circuit board? Ever seen a light go bad?

Damn...might have to go pick up a DK2S as a back-up until I get this sorted out.

Worst case scenario...say the board is fried. How do I go about getting it repaired or replaced?

Thanks again for any assistance getting this fixed.

Scott

[rjohnstone]

You can bypass the battery box altogether (because they are cheap POS anyway) and see if that is the issue.
Use two 9v battery clips and wire them in series for 18v.
Never seen one of the LEDs die before, but it's not unheard of.
I still suspect it's a board component that is dying.
If you are the original owner and you bought it from an authorized dealer, there is a chance JCMI will repair/replace the board for you.
They replaced and entire body on one of my PC1's due to a bad route, so chances are good they will help you.

[RobRR]

Its fairly rare for a board component to gradually fail. Mostly they either work, or dont. Ive been working in the defense industry as a Manufacturing Lead Assembly Spc. for the better part of 10 years, and as Axe said, they usually dont go bad. Sure, caps will explode and what not, and shitty solder joints due to lead-free crap, but generally it will work or it wont work. Were not talking about high power equipment here either, 18v is nothing. When looking over my sustainer board when I had to do some trace repairs, I didnt notice any bad soldering or shoddy workmanship, other than what some idiot tried to "fix" the switch.

What I DID notice was shoddy crimping and generally shitty grade wire used for the pickups and their connectors that attach to the board. When I got my PC1, the sustainer wasnt working. Ya know what it turned out to be? Some dolt accidentally wired the bridge pickup, a DiMarzio, like a Duncan. Anyone whos done wiring knows theyre wired pretty much the opposite of each other. Believe it or not, a pickup being wired wrong is enough to throw the sustainer board out of whack. They work on a very calibrated level, and something as simple as the resistance of the pickup being too far out of tolerance will render it inoperable. Another thing I noticed was that the battery box is the cheapest piece of shit known to man.

My suggestions would be to first bypass the battery box temporarily and rule out a power problem as RJ said. Also I would reset the two adjustment pots on it. Counter-clockwise all the way is full power (at least on my board it is), so go full counterclockwise just for testing purposes with both adjustment pots. That will take that out of the equasion. If the power bypass doesent do the trick, I would go over all the wiring with a fine tooth comb, including the input jack (4 wires connected to that), and especially the pickup wire connectors. The cavity cover damn near crimps them at a 90* angle once installed, so they can definitely wear out at that point too.

[rjohnstone]

My suggestions would be to first bypass the battery box temporarily and rule out a power problem as RJ said. Also I would reset the two adjustment pots on it. Counter-clockwise all the way is full power (at least on my board it is), so go full counterclockwise just for testing purposes with both adjustment pots. That will take that out of the equasion. If the power bypass doesent do the trick, I would go over all the wiring with a fine tooth comb, including the input jack (4 wires connected to that), and especially the pickup wire connectors. The cavity cover damn near crimps them at a 90* angle once installed, so they can definitely wear out at that point too.

Rob's right.
I almost forgot about the tight cavity covers. I've fixed all of mine a long time ago, so it didn't cross my mind.
Double check the wiring and make sure you don't have a failing or broken lead.
Now that I think about it, I would almost bet one of the leads to the sustainer driver is the issue.
Would explain the tone change when you flip on the unit.

[Chief_CrazyTalk]

In my years of experience as a lead SMT, I've never seen surface mount parts crack or break. But on that note, the only work I've ever dealt with was my own.

Broken solder joints sound probable though, especially in surface mount. Most overseas companies use inferior solder paste that doesn't hold up well with surface mount parts. The reason surface mount is more prone to breakage is because of the minimal amount of solder, and the shape of the joint. I'm gonna assume that given the assumed size of the board, they may have used 0603 sized parts, which take a bit more finesse to mount than the industry standard 0805.

I mentioned that because I've been seeing a lot of that lately at work, coming from our board house. It's not uncommon for a single board to have multiple cracked resistors, some broken components only becoming apparent during heat testing. I've seen it throughout the years as well elsewhere.

[Axegrinder87]

I mentioned that because I've been seeing a lot of that lately at work, coming from our board house. It's not uncommon for a single board to have multiple cracked resistors, some broken components only becoming apparent during heat testing. I've seen it throughout the years as well elsewhere.

I'd say you might want to find another supplier, as that's inexcusable. I imagine that's just how the game is though, which is why I left the industry. Hard to tell the customers, "No, we actually do good work" amongst the dozens of bullshit manufacturers. It became apparent that it also wasn't worth my time to ensure quality anymore. I can't do shit work, and I can't be told to cut corners either, to lower costs.

[adampone]

Rob's right.
I almost forgot about the tight cavity covers. I've fixed all of mine a long time ago, so it didn't cross my mind.
Double check the wiring and make sure you don't have a failing or broken lead.
Now that I think about it, I would almost bet one of the leads to the sustainer driver is the issue.
Would explain the tone change when you flip on the unit.

how did you go about fixing the tight cavity covers?

[rjohnstone]

how did you go about fixing the tight cavity covers?

Routed the cavity to get more clearance for the wiring. (Dremel works wonders for this situation)
The board sits too high in the cavity. The toggle holes are what you have to route. Sure it makes them stick out a tad higher on the face of the guitar, but you really have no other option.
Not much material in there, so you have to be very careful.