diagnose this one...

gigamesh · 30th August 2007

This power amp is not working. It's from Ibanez "soundwave 65" bass combo amp. It's a nice little amp but was only $80 so I'm really trying to avoid paying someone to fix it. Here is what happened:

Turned it on, power light came on, plugged in guitar...no sound at all. No smell or smoke, just silence. When I opened it up I noticed the fuses were blown. Here is where it gets a little fuzzy: The circuit board denotes that the fuses should be F3 and F4 at 250V. The fuses that were in it are BOTH F4 (could this have possibly played a roll in the problem?). I bought 2 F4 fuses @ 125V to replace it (I was informed that all I need is 125V since I'm only connecting to American wall outlets). SO: based on the pictures and that information, does anyone have ANY idea why it's still not working? Thanks!

amishsixstringe · 30th August 2007

Did the new fuses you installed blow? Something most likely caused them to in the first place. Power supply caps/diodes or a short somewhere would be a likely cause for them to blow. If they did not blow, but it is still not working, you probably fried something before the fuses blew the first time, therefore there is no current even running through the new fuses you have installed. Do you have access to a DVOM? If not, it might not really be worth fussing with too much.

Neil

gigamesh · 30th August 2007

Yes, they did blow! I just took another look. So what could that mean?

dementedchord · 30th August 2007

well you've obviously been beating on it... look at the heat scaring near the outputs... i would think about desoldering them and see if it powers up then... after that look to the power supply...diode stack/filtercaps/regulators... in that order...

gigamesh · 31st August 2007

You mean near the heat sink? I think that might just be bad amp design, because no matter how loud you run this thing, it's always extreeemely hot. Anyway I just noticed the circuitboard has F2 and F3 listed, and I had F4s installed...could that have contributed to them blowing right away again?

30th August 2007	#1
gigamesh Gear interested Joined: Mar 2007 Location: Minneapolis Posts: 23 Thread Starter	diagnose this one... This power amp is not working. It's from Ibanez "soundwave 65" bass combo amp. It's a nice little amp but was only $80 so I'm really trying to avoid paying someone to fix it. Here is what happened: Turned it on, power light came on, plugged in guitar...no sound at all. No smell or smoke, just silence. When I opened it up I noticed the fuses were blown. Here is where it gets a little fuzzy: The circuit board denotes that the fuses should be F3 and F4 at 250V. The fuses that were in it are BOTH F4 (could this have possibly played a roll in the problem?). I bought 2 F4 fuses @ 125V to replace it (I was informed that all I need is 125V since I'm only connecting to American wall outlets). SO: based on the pictures and that information, does anyone have ANY idea why it's still not working? Thanks!

30th August 2007	#2
amishsixstringe Lives for gear Joined: Mar 2007 Location: Athens, Ohio Posts: 1,267	Did the new fuses you installed blow? Something most likely caused them to in the first place. Power supply caps/diodes or a short somewhere would be a likely cause for them to blow. If they did not blow, but it is still not working, you probably fried something before the fuses blew the first time, therefore there is no current even running through the new fuses you have installed. Do you have access to a DVOM? If not, it might not really be worth fussing with too much. Neil __________________ My Recording Studio Build Thread: http://www.gearslutz.com/board/photo...hens-ohio.html Photobucket Page with TONS more studio photos: http://s152.photobucket.com/albums/s...ding%20Studio/ www.myspace.com/amishelectricchair www.gcrecords.com

30th August 2007	#4
dementedchord Lives for gear Joined: Apr 2006 Posts: 885	well you've obviously been beating on it... look at the heat scaring near the outputs... i would think about desoldering them and see if it powers up then... after that look to the power supply...diode stack/filtercaps/regulators... in that order... __________________ this is dyslexic of borg... your ass will be laminated...

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31st August 2007	#5
gigamesh Gear interested Joined: Mar 2007 Location: Minneapolis Posts: 23 Thread Starter	You mean near the heat sink? I think that might just be bad amp design, because no matter how loud you run this thing, it's always extreeemely hot. Anyway I just noticed the circuitboard has F2 and F3 listed, and I had F4s installed...could that have contributed to them blowing right away again?