moodydan
I love the punk rock.
I'm working on a G-7700 for a friend; in transit, it was dropped, kicked, smashed, who knows? The result was the F-3058 circuit board for the left channel was shattered. When he plugged it in to see if it worked upon receiving it, transistors shorted all along the left channel.
So, I got a new (old) F-3058 board (from a 6700), replaced the main outputs with pairs of NJW3281G/NJW1302G, and replaced all of the following in the power amp section: VR01, VR03, TR01, TR03, TR05, TR07, TR09, TR15, TR17, TR19, R03, R37, R53, R51, R57, R59, R65, R81, R85, R87.
My DC Bias and Offset have been set and both are staying set (not drifting).
I power up, get the relay click, and get great sound out of the right channel (which didn't have any damage). The left channel sounds good, but if I turn past the "10" mark on the volume dial (approx. 7 o'clock position), the receiver kicks into protection every time. If I disconnect the left speaker, this does not happen.
Some other measurements I've taken:
Voltages at both sides of
R601: 41.5v/23.99v
R604: 43.5v/23.99v
Votage across ZD601: 22.99v
I feel like I'm close, but I'm looking for a lead!
So, I got a new (old) F-3058 board (from a 6700), replaced the main outputs with pairs of NJW3281G/NJW1302G, and replaced all of the following in the power amp section: VR01, VR03, TR01, TR03, TR05, TR07, TR09, TR15, TR17, TR19, R03, R37, R53, R51, R57, R59, R65, R81, R85, R87.
My DC Bias and Offset have been set and both are staying set (not drifting).
I power up, get the relay click, and get great sound out of the right channel (which didn't have any damage). The left channel sounds good, but if I turn past the "10" mark on the volume dial (approx. 7 o'clock position), the receiver kicks into protection every time. If I disconnect the left speaker, this does not happen.
Some other measurements I've taken:
Voltages at both sides of
R601: 41.5v/23.99v
R604: 43.5v/23.99v
Votage across ZD601: 22.99v
I feel like I'm close, but I'm looking for a lead!
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