HELP CABLE UNSOLDERED in Mesa boogie dual rectifier multiwat
- Thread starter byfer91
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There isn't a schematic available, so this is just guess work:
On the older 3 Channels, the ftsw and the fx loop were supplied 15 volts for switching. Your amp seems to be using 12 volts. Since your loop is series, the circuit is different from the old one. However, Mesa often uses jfets for switching. On the old schematic, two resistors, a diode, and the 15 v supply were used for a switch and to power the ftsw.
Your amp seems to use those resistors, diodes, and the jfet along with the relay for the loop and part of it runs to the rotary knob and DIN (probably as power). If something failed, it could be pulling power to ground and reducing the voltages. Since your ftsw doesn't work, the problem is very likely on that daughter board right around where the resistors are, or up/down the track from them.
The cathode of one of those diodes is going to point right to the pin of the DIN that needs power.
On the older 3 Channels, the ftsw and the fx loop were supplied 15 volts for switching. Your amp seems to be using 12 volts. Since your loop is series, the circuit is different from the old one. However, Mesa often uses jfets for switching. On the old schematic, two resistors, a diode, and the 15 v supply were used for a switch and to power the ftsw.
Your amp seems to use those resistors, diodes, and the jfet along with the relay for the loop and part of it runs to the rotary knob and DIN (probably as power). If something failed, it could be pulling power to ground and reducing the voltages. Since your ftsw doesn't work, the problem is very likely on that daughter board right around where the resistors are, or up/down the track from them.
The cathode of one of those diodes is going to point right to the pin of the DIN that needs power.
now remove the motherboard only one hand to get a better view of the circuit and see where they come 5v and could find a single component that converts 12v to 5v , is LM7805C volt regulator, tomorrow volvere to ride the circuit and check that It is working properly, if it does not work I'll make a replacement and he change .
http://www.ti.com/product/lm7805c
http://www.ti.com/product/lm7805c
I was actually coming to talk to you about that. The Road King schematic shows a regulator from 12 volts to 5 V. It also shows some of the updates to their concepts for switching. I know it won't translate directly to a Reborn, but some of the ideas will carry over. The two resistors and diodes in the pictures you showed are in a similar loop bypass circuit on the Road King, too (page 13).
On the Road King, the 5 V powers the LM3914 on pins 3 and 6 to switch channels with the ftsw. There is a small circuit that connects directly to the DIN from it (page 11).
On the Road King, the 5 V powers the LM3914 on pins 3 and 6 to switch channels with the ftsw. There is a small circuit that connects directly to the DIN from it (page 11).
, the problem finally is solved, thanks so much to all helps and comentsSimilar threads
