Why? It seemed like a good idea at the time and I was desperate to get the thing fixed. I couldn't find these in production anymore and I was in a big hurry so I substituted Q7 for KSC1845FTA Appears to be normal now after the most recent damage.Īs listed in the schematic, Q7 is listed as 2SC2235 and Q8 as 2SA965. Q10 - Has continuity across all pins, same as before.Ĭ3 - Had a slightly puffy top so I replaced it. It was the same color-code as R15 on the working HF board which read 8200ohm. That didn't match up with the original on the board. R15 - Listed in the schematic as 6200ohm. R17 - It was visibly burnt last time, but not as badly as this time. Since I can't add anymore, here's a link to everything I've tested on the board now, in schematic form: I can add more later, but I'm limited to six attachments. I'm only mostly embarrassed to show this.Īttached are some pictures of other places around the boards. I see no visible damage and everything seems to test as expected. Now that I'm not all stressed out about time, I realize I may have gotten something mixed up.Īs it stands now, one of the HF boards seems to be fine. I see now the Low Frequency board is on a different base, which I mistook the other HF board for. They're basically identical only they had different transistors. It wasn't until earlier when I started revisiting this that I realized there are actually *two* high frequency amplifier boards, with only one represented in the schematic. It's been very useful and from everything I've checked so far, has been accurate.
That site has full schematics for the entire speaker system. In my haste, I chose something I thought would be "close enough" and probably chose waaaaay incorrectly.įor reference for anyone willing to give this a go: Part of the big problem with my original repair was that I couldn't find exact matches for replacement parts for two of the transistors. I'd like to now sit down and take the time to attempt a proper repair. With the wedding being 2 days away at that point, I stuffed it to the side and went about finding a different set of speakers. I quickly killed the power to it but clearly some serious damage had been done. I heard a "things aren't going to work out for you" electrical buzz from the board for a few seconds before a loud pop and bad-news smoke started to rise. I left the speakers and sub unplugged from the board and plugged it in. I was trying to get the speakers working for my upcoming wedding (sound system for a small venue on the cheeeeap) so I quickly bought new parts based on a schematic I found online and popped them in.
Further poking around with a DMM found most of the transistors on the board had continuity across pins and a cap had a slightly puffy top. I popped open the subwoofer and poked around until I found a toasted resistor on the High-Frequency amplifier board. I swapped the speakers around and got the same thing, ruling out a speaker issue.
No sound on the left channel, and very weak/distorted sound in the right channel. Moved them back to my computer a few days later and found really weird sound coming from them. Used them for the sound system at a gathering (mostly people hooking their phones up to play music from them) and everything was fine. Hello everyone! I've browsed around a bit looking for some help on repairing some speakers that have gone kaput and this place looked really helpful! I've tried to repair this on my own almost a year back but was in a rush and found myself out of my depth in short order.