Hello all
I have just started playing again after almost 20 years of not touching any of my guitars. I've been playing mainly my Eko acoustic but today decided to try my Fender Jag-Stang through my old, but virtually unused Park Marshall G10R amp, which I'm unable to get to work. When I plug the amp in to the mains power socket the red power light comes on but there's no feedback noise or any noise whatsoever, even with the volume turned to maximum. Likewise when I connect it by jack cable to my guitar. I have checked the open back of the amp and both the red and white cables are plugged in to their respective sockets correctly and there's no visible signs of wiring damage. In fact, the amp looks brand new.
Any ideas about this?
Many thanks
Comments
If so there's a good chance it's a corroded switch contact in the headphone jack, which disconnects the speaker. It will need cleaning or probably at worst re-tensioning.
If not, it's either the speaker or the power IC most likely.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
It may be the power as I'm not sure I'm using the original/correct mains power lead, though the red LED power light is on.
Thanks again
The problem is that no sound at all is coming out, which leaves the speaker, the power IC ('chip' - it's a single one in these amps) or the connection between them, which is in the headphone jack. It is *just* possible that the problem is earlier in the signal chain, but if so I would expect faint hiss to be audible from the speaker.
The reason I think it's most likely to be the headphone jack is that the amp hasn't been used for a long time, and sometimes a spot of corrosion will form in it and do exactly what you've found. Re-tensioning it just means bending the springy bit (technical term ) of the headphone jack slightly so it makes a better contact, but you need to be careful not to make it worse, it's quite easy to if you're not familiar with doing it. Often cleaning it - sometimes even just putting the headphone plug in and taking it out, if it disturbs the corroded spot - can be enough.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
The correct reading won't be zero ohms, it will be either about 3 ohms (4-ohm speaker) or about 6 ohms (8-ohm speaker). A reading of zero means the speaker is shorted - rare, but not unknown.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein