Uh OH. FREE STUFF.

R

remingtonbo2001

New member
Alright folks. I got a deal. I have a Tech 21 Double Drive, OR a 59/Custom Hybrid. Your choice, it's FREE for anyone who can resolve this unfortunate issue. I recently got a Vox Cambridge, great amp, did the 56 mod. Thanks again Chris, good business. Well, somehow, I accidently broke a pin off the chip when resecuring the optocoupler. Alright no biggie. I purchased another and installed to the exact instructions. Low and behold, I turn the amp on and something starts to smell. I turn it off. The Power transistor was incredibly hot. I tried again. Same deal. Third time, nothing came on, not even the LED. I mean, you can hear it click on and off, ect, even the first couple of times, but not this time. So I redid the wiring, double checked everything. Turned it on, nothing, but a smell. I went through 3 different chips. With each one the same deal. When I touched the large blue capacitor next to the power transistor, I recieved a small shock. The I touched the 56 chip, again small shock. So, it seems obvious power is running through. The slow blow fuse looks alright. The only thing that looks burnt is Z04, which is a rectifier/diode. It was that way before. I change out the optocoupler again. Still no prevail. All the joints look good. So, what's up. Is it the blue capacitor next the power transistor? The electylic capacitor connected to the 56 Chip? I'm serious about this deal. I will pay for SHIPPING. I can't get it into a tech for a month, so I figured if I put enough motivated minds behind this, I could do it myself, with the obvious assistance of someone who knows what the hell their doing. You can post here or send me an PM. Thanks to all in advanced.

Bo
 
Re: Uh OH. FREE STUFF.

remingtonbo2001 said:
Alright folks. I got a deal. I have a Tech 21 Double Drive, OR a 59/Custom Hybrid. Your choice, it's FREE for anyone who can resolve this unfortunate issue. I recently got a Vox Cambridge, great amp, did the 56 mod. Thanks again Chris, good business. Well, somehow, I accidently broke a pin off the chip when resecuring the optocoupler. Alright no biggie. I purchased another and installed to the exact instructions. Low and behold, I turn the amp on and something starts to smell. I turn it off. The Power transistor was incredibly hot. I tried again. Same deal. Third time, nothing came on, not even the LED. I mean, you can hear it click on and off, ect, even the first couple of times, but not this time. So I redid the wiring, double checked everything. Turned it on, nothing, but a smell. I went through 3 different chips. With each one the same deal. When I touched the large blue capacitor next to the power transistor, I recieved a small shock. The I touched the 56 chip, again small shock. So, it seems obvious power is running through. The slow blow fuse looks alright. The only thing that looks burnt is Z04, which is a rectifier/diode. It was that way before. I change out the optocoupler again. Still no prevail. All the joints look good. So, what's up. Is it the blue capacitor next the power transistor? The electylic capacitor connected to the 56 Chip? I'm serious about this deal. I will pay for SHIPPING. I can't get it into a tech for a month, so I figured if I put enough motivated minds behind this, I could do it myself, with the obvious assistance of someone who knows what the hell their doing. You can post here or send me an PM. Thanks to all in advanced.

Bo
Click to expand...
I'm guessing when you damaged the chip, the next component in the power signal was damaged due to excessive voltage/current. Check the next component that gets voltage from the chip (the next component in line). I bet that's the problem.
 
Re: Uh OH. FREE STUFF.

Do you mean the electryic capacitor. It is connected to 2 leads going to the circuit board/chip? Or something else. I didn't have the amp on when I broke the pin of the original chip. I didn't turn it on till the new one was installed. That's why I'm muffed. I think I might try that though. Thanks.
 
Re: Uh OH. FREE STUFF.

remingtonbo2001 said:
I think we have a winner folks :laugh2: You nailed it. Haha. How much were you willing to bet? Just curious.
Click to expand...
a broken single coil pickup.
 
Re: Uh OH. FREE STUFF.

I would start by replacing any parts that resemble charcoal . . . even if they looked like that before. ;)

Artie
 
Re: Uh OH. FREE STUFF.

I just bought a DC voltage meter, resistance, capacitance, ect. Hopefully this will help. My speculation is that it is the large blue capacitor next to the power transistor, or as HD might has suggested, the electrylic capacitor next to the semiconductor chip. I keep getting shocked by the Blue Capacitor, so I think that may be it. Then again, my clothes are still kinda static-y. Mucho gracias for all the help.
 
Re: Uh OH. FREE STUFF.

Did you install the chip the correct way round? In my experience of electronics, it's usually the last thing you did.
 
Re: Uh OH. FREE STUFF.

Be wary of the electrolytic capacitor, if things are fitted incorrectly it could go bang.
 
Re: Uh OH. FREE STUFF.

stevie_bees said:
Did you install the chip the correct way round? In my experience of electronics, it's usually the last thing you did.
Click to expand...

What do you mean? It would only go one way right? You have to screw it to the heat sink. The little plastic coating is between it and the heat sink. It has some paste around it. I just don't know. Uhhhhh.....If the LED light went out, would this cause it from working? It's not clicking on. But, none of the lights are working, ie...channel 1/channel 2. So I would figure the problem to be at the beginning of the power source. Right? Wrong? Nothing looks burnt. That diode I was previously talking about, well it was a black stripe around it. Nothing is burnt out. When I tried turning it on again, it started smoking at the later part of the chain, around the tube. But I put a 50v Electrylic Cap instead of 100va. That might be the problem. I wish I could take it in, but it's just too long of a wait. Well, I have 10 days to figure out how to do this. Thank you everyone. If your suggestion works, I'll keep my end of the bargin.
Later.

Bo
 
Re: Uh OH. FREE STUFF.

The caps can explode like an M-80. Just gotta be careful. They also hold a charge and can kill you LONG after you've unplugged the amp.
 
Re: Uh OH. FREE STUFF.

There's usually a tag or mark on the chip, and some sort of mark on the board to ensure the right legs go in the right place.
 
You must log in or register to reply here.

Similar threads

idsnowdog
I built this
Replies
13
Views
161
playas
playas
Rich_S
Pickups for FREE Telecaster
Replies
19
Views
176
Rich_S
Rich_S
ErikH
NAD - Boss Nextone Stage
Replies
16
Views
763
Mincer
Mincer
8
JCM600...what I think
Replies
8
Views
215
Securb
Securb
contiContiCONTI
NGD: PRS Silver Sky SE - Mixed Feelings
2
Replies
37
Views
384
Rex_Rocker
Rex_Rocker
Back
Top