Crossover help?
Hi to all I'm hoping someone might be able to help.
I've tried to upgrade components within my crossover and now have no HF signal.
The tweeter checks out.
I've searched for bad joints , shorts etc but can find nothing obvious.
Today I've pulled the upgraded components from the Hf circuit but still have nothing.
Using a continuity test its all good up to the main cap and after back to the terminal.
I do get a bleep from both terminals so assume thats the parallel resistor.
I'm at a loss as to why its gone completely dead.
Anyone got ideas how to check the network front to back with only a basic multimeter?
Thanks in advance if someone has some ideas
Regards Ian
This is example of why one should take photos, more photos and more photos of any equipment one working on. You cannot have too many pictures. If OP took photos prior and wired up exactly the same, only fried components could account for failure. Hand drawn schematic good back up. Also, get value of components in photos if possible.
When I did my last crossover mods, I took tons of photos, got stuck in middle of mods, luckily found the single photo that was at proper angle to see hidden wire. |
Hi and thank you for the replies. The speakers are PMC FB1 they are well known for being overly bright. Its been my intention to follow the + upgrade for years but had never found the crossover changes until recently. . I got hold of the layout with values and found a photo of the upgraded network. The only changes are replace the 3.0 cap with 3.3 and add a 56ohm resistor. I decided to change the ageing cap on the LF and resistors as a what the heck while I'm in there. I removed the network, removed HF resistor, positioned the new, removed cap, positioned new, same for LF positioned 56ohm flipped it over and soldered everything in. clipped tails and reinstalled network, no HF. Removed network desoldered 1 end of 56ohm, checked no change. Checked tweeter operation, working. Removed network checked for shorts, poor joints and poked around with continuity tester, nothing obvious. Removed HF parts refitted originals checked, no change. Since then I've been poking around trying to find anything amiss. I've posted some pics on my system
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I don't see your system. Look at this thread,https://forum.audiogon.com/discussions/tweeter-blown-or-crossover-how-to-check |
I searched and saw picture of upgrade, you have circuit board, per grannyring likely damaged pad or trace. Solder pads easily damaged in removal of original components, need proper desoldering equipment, don't force anything. Believe me I know from experience.
Above if you're 100% sure drivers working. |
I used a sucker and wick, the tracks are pretty robust. I get a a bleep up to and away from the cap, can't test the cap but neither new or old refitted made any difference. I'll play around again tomorrow see if I can find a break. Really struggling with this one. Any idea what reading I should get from the coil? Its showing 0.9 .71mm |
