Went I flipped the amp I cut the wrong one. should I cut the 3.9? I will have to get a replacement fot the one I cut by mistake.
Cut the 3.9.
These outputs are in parallel groups so you will have to replace them in groups. Right now we're simply trying to see how much damage there is.
These outputs are in parallel groups so you will have to replace them in groups. Right now we're simply trying to see how much damage there is.
Desolder the two remaining 20 something gate legs and measure them out of the board. Do they read low?
So I cut the 2 20.** and not I have:
8.00M
8.02M
8.02M
42.3(gate disconnected)
36.6(gate disconnected)
cut
other side
7.06M
7.07M
cut
cut
7.07M
7.07M
8.00M
8.02M
8.02M
42.3(gate disconnected)
36.6(gate disconnected)
cut
other side
7.06M
7.07M
cut
cut
7.07M
7.07M
So i powered up the amp and went to touch the speaker to it and I saw smoke coming from on side and turned it off. I couldn't see where it was coming from. It was coming from the area of the transistors I think.
When I turn it on to test now its draining the power supply down to 8.23vdc again. Maybe the other transistors are shorted now?
Ok so now I have:
9.68M
9.66M
9.63M
gate disconnected
gate disconnected
cut
Other side
20.4
0.5
cut
cut
41.4
21.5
So are all the 2nd side ones bad?
9.68M
9.66M
9.63M
gate disconnected
gate disconnected
cut
Other side
20.4
0.5
cut
cut
41.4
21.5
So are all the 2nd side ones bad?
Probably. It's possible that the drive circuit was damaged.
In this amp and similar amps, expect the replace the gate resistors, the 20 ohm driver resistors and the MMBTA06 and MMBTA56 driver transistors.
If the 0.1 ohm source resistors are out of tolerance, you may have protection circuit damage.
In this amp and similar amps, expect the replace the gate resistors, the 20 ohm driver resistors and the MMBTA06 and MMBTA56 driver transistors.
If the 0.1 ohm source resistors are out of tolerance, you may have protection circuit damage.
Ok so the gate resistors are the 0,1ohm resistors? Are they 1 watt? are the 20ohm resistors 1/4 watt? are where are the mmbta06 and mmbta56 located?
The 0.1 ohm source resistors are the large 2w resistors.
Order the SMD resistors by size (likely all 0805).
What's the PC# on this board?
Order the SMD resistors by size (likely all 0805).
What's the PC# on this board?
Ok what SMD resistors are the ones needing to change also should I be worried about something missing in D3(I uploaded a pic before).
PC-2037-D
PC-2037-D
Q120, 121 and those in similar locations in the circuit commonly fail.
R165, 166 and similar commonly fail.
All gate resistors commonly fail when the output transistors they drive fail.
D3 is likely a 33v zener in a sot-23 package.
See attached.
R165, 166 and similar commonly fail.
All gate resistors commonly fail when the output transistors they drive fail.
D3 is likely a 33v zener in a sot-23 package.
See attached.
Should I just replace the commonly fail items or should I just replace them to be on the safer side?
Are the big 2w gate resistors metal oxide?
Would this be a good replacement?
http://www.mouser.com/ProductDetail...=sGAEpiMZZMtlubZbdhIBIKyczXpI2OGsIpXVfvrxYME=
Would this be a good replacement?
http://www.mouser.com/ProductDetail...=sGAEpiMZZMtlubZbdhIBIKyczXpI2OGsIpXVfvrxYME=