Hi everyone,
I'm new to this forum and I'm not an engineer. I do know some basics and repaired guitars and amps, but this one amp is a pain....
Here's the story. Two fuses blew up everytime you switched it on. I replaced 4 Resistors of 33Ω (R428 t/m R431 on the ME_IV_E_1_cir.PDF), they were totally burned out. Now the fuses stay OK, but there is terrible hum. If I take out R429, the hum is gone and there is sound, but very little and very sharp, not the way this amp should sound at all.
The hum really sounds like there is direct current or broken ground somewhere. Now by checking the amp I found a loose cable as well, black (should be some kind of ground right with that color...) and this is connected to the 80160 board on the same schematic, I figured out that should be number three going to the left Connector C pin 7, but the weird thing is this is not the ground but the signal wire. I tried both btw and none of them take the hum away, not making any difference, but I want to know where to hook up this cable. the ones connected are two times yellow and two times red, leaving this black cable as the fifth.
Can anyone make sense out of this and point me in the correct direction please?
Very much appriciated.
With kind regards,
CornElvis
I'm new to this forum and I'm not an engineer. I do know some basics and repaired guitars and amps, but this one amp is a pain....
Here's the story. Two fuses blew up everytime you switched it on. I replaced 4 Resistors of 33Ω (R428 t/m R431 on the ME_IV_E_1_cir.PDF), they were totally burned out. Now the fuses stay OK, but there is terrible hum. If I take out R429, the hum is gone and there is sound, but very little and very sharp, not the way this amp should sound at all.
The hum really sounds like there is direct current or broken ground somewhere. Now by checking the amp I found a loose cable as well, black (should be some kind of ground right with that color...) and this is connected to the 80160 board on the same schematic, I figured out that should be number three going to the left Connector C pin 7, but the weird thing is this is not the ground but the signal wire. I tried both btw and none of them take the hum away, not making any difference, but I want to know where to hook up this cable. the ones connected are two times yellow and two times red, leaving this black cable as the fifth.
Can anyone make sense out of this and point me in the correct direction please?
Very much appriciated.
With kind regards,
CornElvis
Attachments
-
124.3 KB Views: 113
-
119.2 KB Views: 104