Way Huge Pork Loin switching issue

[methodofcontrol]

i've got a pork loin that is acting peculiar.
when you press the switch, one of several different options will occur:
-the light will come on, the effect stays off
-the light stays off, the effect comes on
-both light and effect go off/on
-neither light nor effect is affected

i found a schematic here: 松美庵エフェクターBBS

the effect is controlled via momentary switch and relay. the switch tests good. i'm wondering if the relay is failing?
i've never heard of a relay failing intermittently... thoughts?

[Audiotexan]

Just as an FYI on that schematic (in case you didn't translate the page)..it appears to be a mod-site. So I'd take that schem with a grain of salt.

In the development of the TS-808, Clean Mix function has been added to Pork Loin.
It is a quality Ibitsu-on suitable for Stratford + Fender amp, but lack both a sense of edge, presence to me you want to use the Semiako Poriton system amplifier, it is more boomy. So I was MOD OD-1 wind sound as out.

You think I want to report a MOD content.

1. Parts ... C11, C15, C21, which has been removed
2. Parts ... R7 → 1K you have replaced, R15 → 1K
3. Add 1N914 in series with the parts ... D3 that you have added

Result
CURVE will have the same functionality as the VOICE of ZEN DRIVE.
I obtained OD-1 wind sound in 3:00 position full ~.
I will give the TS-style sound in the 12:00 to 2:00 position.
In addition, PRES (presence) knob 2pin and 1pin it, or should be set to full
I leave the short between. For Komori is terrible, (presence circuit this time
In remodeling, you have to disable the feature. )

[Note]
For reference, I will upload a circuit diagram of the actual equipment.
I also shown below the value of the resistor is not listed in the figure.
IC, capacitor and diode model number, resistance value is different from the actual
Become place will be seen here and there.

Back to the question at hand though.
Basically it sounds like a momentary switch which then engages a latching circuit.
Much like what Boss/Ibanez uses.

Something in that latching section isn't functioning to keep it in latched mode.
I'd verify transistors, caps, and resistors around that portion of the circuit. Unfortunately I'm not familiar with this pedal (couldn't even tell you if it's surface mount [aka SMT] technology, but I'd bet it is). Make sure you have good grounds in that section as well.

[mozwell]

same sch, but with values, i dont know how correct this is.....

[J M Fahey]

the effect is controlled via momentary switch and relay. the switch tests good. i'm wondering if the relay is failing?
i've never heard of a relay failing intermittently... thoughts?

What you describe points to a mechanically latching relay, a weird contraption which is sometimes used in pedals, to avoid killing the battery in minutes with the coil consumption.

A delicate balancing act, can very well picture a failing/dirty contacts one.

Problem is that both springs and coil "pull" are as weak as possible, to lower consumption during the brief flip-flopping phase, which maximizes dirty contact problems.

To boot, replacements are as rare as hen's teeth.

Read the latching relay section:

Relay - Wikipedia, the free encyclopedia

[methodofcontrol]

i studied the schematic and there is no information on it about the switching mechanism. it doesn't appear to be a standard fet controlled boss style flip-flop. the switch checks out, the relay is intermittent but the relay does not control the LED, just the input/output send/return signal flow, so the fact that the signal flow AND the LED are acting intermittently tells me there is a shared component that's not doing it's job, anyone have documentation of the switching system for this? (or any Way Huge pedal would probably have a similar flip-flop i can study)
the issue may lay with some of the surface-mount components... in which case, i might have better luck modifying it to 3PDT true bypass, but i probably still need that switching info to determine how to make the circuit "always on" for the standard 3PDT implementation.

[Audiotexan]

<Edits in blue>

...it doesn't appear to be a standard fet controlled boss style flip-flop.

I should have put 'like' in italics above when I said "Much like what Boss/Ibanez uses." I was trying to imply 'think along similar lines'...but Juan put what I was thinking and added another completely viable possibility into much better context in his post.

...the switch checks out, the relay is intermittent but the relay does not control the LED, just the input/output send/return signal flow, so the fact that the signal flow AND the LED are acting intermittently tells me there is a shared component that's not doing it's job...

Even though the switch seems ok (and it probably is), the latching action would appear to be held by the relay in this case (again, if Juan and my guess is right). All credit to Juan for bringing me round to his way of thinking. I meant that I agree with his initial thoughts on the possible implementation given the updated information. Apologies for it reading like that's what I said all along! It wasn't what I intended to convey. If that latching relay isn't holding properly (or as you said: is intermittent), then that would quite possibly confirm the theory that it's a latching relay. Not a guarentee, but that's how I'm leaning at this point.

If the LED is dependant on a secondary aspect of the signal/voltage that's being switched (or latched), then the relay could indeed still affect the LED aspect as you mention, as the relay would indeed be the shared (LED depending upon the latched condition) component.

You've already stated that "relay is intermittent" -you have a confirmed bad part! Huzzah! Replace it! =)

Then continue to troubleshoot from there! Don't make the mistake I often do, and over-think it beforehand. lol

*sigh* I hate the English language sometimes (and my lack of command thereof all too often). More so when dealing in technical aspects. One of my poorer posts coherency-wise for certain.

On the plus side: relay's are typically easy enough to disassemble, and you can clean the contacts...provided it's a corrosion/oxidation issue. If it's a weak coil...then it's replacement only IME.

[J M Fahey]

This is what I think you have.

What The Crowther Hotcake uses: a bistable relay which does not need a constant current feed all the time while it's on , but a strong positive pulse one way, then another strong negative pulse to turn it off.
Those pulses last fractions of a second



The beast exposed:



It has a small leaf with a tiny magnet on the tip and between 2 iron strips, it will stick to one *or* the other and stay there.
What magnets do

To make it "jump", there's a coil around it which pushes it one way or the other depending on current polarity.
To avoid needing 2 supplies (+ and -) one end of the coil is grounded and the other fed through a capacitor C8.
When it (momentarily touches +9V, it goes up/right and stays there; the next footswitch push grounds it and the pulse goes the opposite way.
Resistor R13 limits peak current and protects S1 contacts which would be pitted eventually.

VERY clever.

[methodofcontrol]

thank you for the hotcake schematic! good post! however, the pork loin uses a momentary switch for activation so i'm thinking Audiotexan hit the nail on the head in that it's a boss styled switching system with a latching relay. this allows for true bypass without using a 3PDT.
since the relay and LED are engaged independently of one another, i'm starting to think there's a bad ground or solder joint in the pedal.
thanks for sticking with me on this, guys! i'll post more after i inspect the solder side.

[methodofcontrol]

alright, found a number of suspect solder joints but reheating them solved nothing, just gave me a little peace of mind. further research suggests the switching circuit may more closely resemble this: http://geofex.com/FX_images/ltchrly.gif

which led me to look into one of the surface mount chips on the jack/relay board, i discovered it's a flip-flop cmos chip. i don't know if that's the issue, but in the process i also discovered dunlop may send me a new jack board if i ask them nicely. so i'm going that route at the moment. it's a more practical solution as i've spent more time fixing this silly pedal than playing it.