How do I troubleshoot a 'no signal' issue?

A silly suggestion is to plug in a different guitar and see if the problem still happens. Have you checked the link your using to connect to the amp? For example is it a faulty lead, a loose jack plug on the end of the lead or an intermittent signal from a wireless connection? You could also check the pickups on the actual bass guitar.
Pick ups don't often cause issues but they can become faulty because of age, corrosion, short circuits and if they're badly fitted.

This sounds like one of this nasty problems with the solder points. One of them might be faulty so sometimes there is a contact sometimes not. You could try to locate it by knocking gently with the plastic end of a screwdriver on the pcb. If vibrations cause the noise you could check all solder points optical or just resolder them. There are not too many. Also check all potentiometers! As they are mechanical parts vibration caused issues can be found here very often especially on their solder points.

I will answer this assuming you have connected the inputs and outputs of both the pedals AND the amplifier/guitar properly. Double-check your connections! ;)

Otherwise...Have you checked all the patch cables to make sure they're ALL working properly? That's usually the culprit in a situation like this, all other things being equal. Cables take the majority of abuse in your signal chain and also happen to be the weak link in the signal chain as well. It only takes one bad patch cable in a series to interrupt the signal.

I would take a pedal with perfectly functioning inputs and outputs and use it to test each cable yer using. If you verify all the cables are in fact working properly (and you are 100% certain everything is connected correctly), that indicates there might be an issue with the pedalboard's onboard electronics. At the most simple, the "From Guitar" or the "To Pedal" or the "To Amplifier Input" jack might be bad. One or more them, in fact, but it only takes one to entirely interrupt that signal chain. The loop section is less straight-forward in that if one of the loops has a bad input or output jack, that shouldn't affect the overall signal chain, nor the inclusion of the other pedals in said signal chain.

So, I think it's one of three things:

1. The pedals, guitar, or amplifier are not properly connected;
2. You have a bad patch cable;
3. Something has gone wrong with the electronics onboard the pedalboard, and this will probably require service.

Hope that helps.

Johnny

The power amplifier is the UPC1188H It will be attached to the heat sink with thermal grease on the back side of it.

Before you change it, Make sure to clean the contacts in the headphone and speaker plug as there are several interupts that may be dirty or corroded and may be preventing your music signal from getting through.

If the headphones work fine- that amp chip is driving them, the fault if the main speaker does not work will be one of those interupts. Contact cleaner should take care of the issue on the headphone jack- just spray the contacts down from the open side of the chassis and plug and unplug a number of times to clean up the contacts. Do the same for the external speaker jack

Many try to use poor quality guitar cables and have the problem. The sleeve of the guitar cable plug turns on the battery in the guitar. Always loop the guitar cable through your belt or the guitar strap to avoid the cable wisting the plug in the guitar causing noise and WEAR that wears the plug sleeve to the point it no longer will activate the guitar.

The half-way cord is the clue. Read up on unbalanced and balanced lines and TRS connectors.
One of these requires TRS connections and the signal is being carried on the RING of the TIP-RING-SLEEVE connector. Plugging in half-way the TIP touches the ring pickup contact. The emgs one MAY use TRS type cables and there may be a reason the signal and hot of these are reversed. If I could find schematics on all this equipment I could unravel the exact cause. You could make an adapter with a Stereo 1/4 inch plug and a 1/4 inch jack by wiring it to swap the tip and ring between them to use for connecting to the emgs guitar. ALSO verify you are using the SAME type guitar cable for both.OFTEN a TRS cable will NOT turn on the electronics when plugged into a guitar. Use an unbalanced instrument cable unless you have the XLR type output. Use of an adapter from the XLR type cable into the Boss will usually not work.

i dont' see where this model has active pickups (guessing this is what you mean by pre-ampped).
The issue can be in a few places.

1) the strings could be too far from the pickups and the instrument needs to be tuned.
2) the pickups are bad
3) your jack is bad
4) the cable is bad
5) your equilizers are not corrected
6) your volume control is turned down or damaged
7) your amp is damaged

this is a small list of the basic possibilities.

Fender Amplifiers are notorious for their reliability issues.However, I'm sure that amp will sound sweet once you get everything working again!

The problem is likely your "tank". The tank contains the springs which create reverb as the guitar's signal is sent through them. A broken spring could be causing your problem.

Luckily, any of the larger music stores should have them avalible.

Good Luck!

-Sheeves

The fact that signal fades is indicative of something with a time delay. The question is where the delay is. If your guitar has a preamp and this device due to wear or contamination on the plug breaks the battery connection within the guitar, the problem could be a worn jack in the guitar that MAY work with your normal cable but not this Amplug due to slight size differences. Other problems could be corrosion on the battery connections in the Amplug. Sometimes headphone cables go bad so try those in another audio source and make sure they are solid. Sometimes these thing have real weak switches and the intial actio of turning it on momentarily connects the batterry, charging the internal filter capacitors which then bleed off... so try working the switch and see if it pops back on..

You gonna need soldering tools. The solder joint is probably bad. I dont think it is the jac that is bad.