| Author | Message | ||
| tdukes
Intermediate Member Username: tdukes Post Number: 149 Registered: 4-2008 |
This morning I was getting a loud hum from the neck pickup of my '77 Series I guitar with the 5 pin cable and no sound at all with a regular 1/4" jack. (I had previously wired the 1/4" jack for mono and used it successfully) The bridge pickup seems to be working fine. I used the guitar this weekend with no issues. What should be my first step in resolving this? Todd. | ||
| lbpesq
Senior Member Username: lbpesq Post Number: 4072 Registered: 7-2004 |
Todd: You might want to unplug the pickups inside the electronics cavity and swap them. Then see if the problem switches to the bridge pickup or stays with the neck pickup. If it stays with the neck, then the problem is with the pickup, if it moves to the bridge, then the problem is somewhere down the line in the circuit. Bill, tgo | ||
| tdukes
Intermediate Member Username: tdukes Post Number: 150 Registered: 4-2008 |
Thanks Bill. I'll try that. Todd. | ||
| tdukes
Intermediate Member Username: tdukes Post Number: 151 Registered: 4-2008 |
I took the back panel off. There are three coaxial cables marked red, blue, and black. I swapped the red and blue and replaced the panel. The hum still occurs when the selector is in the neck position. I infer this means the problem is not with the pickup itself. Todd. | ||
| lmiwa
Advanced Member Username: lmiwa Post Number: 253 Registered: 2-2008 |
I would look at the points where the neck pickup lead connects to the circuit board. Can you post a closeup of the circuit boards? Someone may be able to spot something or mark places to check. | ||
| davehouck
Moderator Username: davehouck Post Number: 8689 Registered: 5-2002 |
Todd; when you say that you had previously wired the 1/4" jack, are you saying that you yourself did the work? If this part of the circuit has been modified by someone other than Alembic, I would be inclined to check the modification; perhaps a bad solder joint, or a short between the lead for the neck side and the ground where they attach to the quarter inch jack. Also, if done by someone other than Alembic, were the recommended resisters used, and do the resisters look good? | ||
| tdukes
Intermediate Member Username: tdukes Post Number: 154 Registered: 4-2008 |
I did the work myself. There is a picture in this thread. When I say there is hum on the neck pickup, that is all there is, hum. No signal. The bright switch, volumn, and filter change the character of the hum (60 Hz maybe), but no (or very little, inaudible) signal from the strings. Todd. | ||
| davehouck
Moderator Username: davehouck Post Number: 8690 Registered: 5-2002 |
Oh yes, I remember that thread now! Did you move the resister leads away from the shielding and back plate? Another quick check; is the pickup selector switch loose? Could it have moved and have developed a grounding problem with the shielding? | ||
| tdukes
Intermediate Member Username: tdukes Post Number: 155 Registered: 4-2008 |
I did now (before I posted my last message). It did not help. The pickup selector seems very secure. I do not believe it has moved. Todd. | ||
| tdukes
Intermediate Member Username: tdukes Post Number: 156 Registered: 4-2008 |
I have talked with Tony at Alembic. I am removing the PF-6 card and sending it to them for testing. Thanks for all the help. Todd. | ||
| tdukes
Intermediate Member Username: tdukes Post Number: 157 Registered: 4-2008 |
I found an old thread where Mica said a PF-6 card was $350. Does anyone think that is not a good amount to insure one for when shipping it back? Thanks, Todd. | ||
| davehouck
Moderator Username: davehouck Post Number: 8691 Registered: 5-2002 |
Let us know how it turns out. I can't recall how much shipping companies charge for that amount of insurance, but I'm thinking the charge for $350 can't be too much, and it's certainly a good idea. I have no idea what the current cost of a PF-6 would be. | ||
| mica
Moderator Username: mica Post Number: 6371 Registered: 6-2000 |
Darn, Todd. The card tests out OK. Maybe you can email a few clear photos of the output jack wiring, and the electronics cavity in general. | ||
| tdukes
Intermediate Member Username: tdukes Post Number: 158 Registered: 4-2008 |
I feared as much. I have taken some pictures of the electronics, trying to show the connections. I took pictures of the control knob as well, but they were all too fuzzy to be of any use. Let me know if they would help. The connections there looked good to me. If there are points I can check with a multimeter, I have one. Let me know if you need additional pictures. Thanks, Todd.           | ||
| mica
Moderator Username: mica Post Number: 6374 Registered: 6-2000 |
Thanks for posting these pics. My dad is going to take a look over them tonight. I'll let you know if he's got any theories after that. | ||
| mica
Moderator Username: mica Post Number: 6375 Registered: 6-2000 |
So there's nothing obvious, but my dad went ahead and replaced the FET on the bass pickup channel on the preamp card since it's a possible cause of the problem if it's intermittent it oculd test fine here and work fine for you until it doesn't. We'll send the card back to you today and you can tell me the results once you reinstall. | ||
| tdukes
Intermediate Member Username: tdukes Post Number: 159 Registered: 4-2008 |
Thanks Mica! I'll let you know when I get the card and reinstall it. Todd. | ||
| terryc
Senior Member Username: terryc Post Number: 1051 Registered: 11-2004 |
Would Mr Sony repair your dvd/camera/tv etc. Having the BOSS repair your gear is priceless! | ||
| toma_hawk01
Junior Username: toma_hawk01 Post Number: 50 Registered: 9-2009 |
This is why I love this organization in more ways than one. | ||
| tdukes
Intermediate Member Username: tdukes Post Number: 161 Registered: 4-2008 |
Mica, your dad has great insight!! I received the card today in the mail. The neck pickup appears to be working for me. At first I was horrified by the amount of distortion, but realized that the gain had been turned all the way up on the PF-6 card. This sounds great on my Fender Twin Reverb, but not so good on my practice amp. I guess it just doesn't have enough headroom. After adjusting the knob down about halfway it sounds great through both the practice amp and the Twin Reverb. Man, this is a great guitar. Thanks again Mica, and tell your dad thanks as well. Also thanks again to Sam for selling this guitar to me (I hope you are not too sad) Man, this is a great guitar. Todd. | ||
| tdukes
Intermediate Member Username: tdukes Post Number: 162 Registered: 4-2008 |
I had just about had my wife talked into the electronics upgrade and a refinish if I were to have had to send the guitar there to be fixed. Todd. | ||
| davehouck
Moderator Username: davehouck Post Number: 8734 Registered: 5-2002 |
Congrats Todd!!! |
