6505+ 8 pin ribbon cable help!!

J

jkkkjkhk

New member
Ok I'll try to keep this short. My amp shorted out or something the other day. I opened it up and all the tubes and fuses were fine but I noticed a small burn on a ribbon cable running from the main board to the power tube board. A little research and it seems the middle 2 prongs are what runs the heaters which would make sense why my amp turns on but power tubes won't light up. The board itself is fine but I'm now looking to get a new cable to see if that's the only problem. I have no idea what type of connectors these are or where to find them, all I know is it's a 8 pin ribbon cable.

Any help is greatly appreciated.
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my 6505+ had sooo many problems. sounded great, but the build was crap. the thing blew more tubes than a prostitute. never figured out what was wrong with it, and once i got my engl, i never really cared to. sold it on craigslist for $800 cash lol

while i never personally encountered your particular problem, i have heard of its prevalence among 6505+ users. it'd probably be best to take it to a pro to diagnose as the problem may not necessarily be (just) the ribbon cable itself, but the regulation of power that flows through it.
 
take that with a grain of salt ,probably a easy fix those ribbon cables are not the best thing...mabye just need new, lots of 5150 experts around here so somebody probably seen that...
 
Thanks, I'm going to try and get the cable and if it works then cool, if not then it was only a few bucks. I talked to a tech and he said he can guarantee he'll know the problem within a few hours, but those few hours cost me $70. If a new cable doesn't work then I'll do that. I don't want to drop a lot of money cause I'm wanting to sell it. But gotta do what ya gotta do.
 
JimmyDoomsday":3ce9yk1p said:
my 6505+ had sooo many problems. sounded great, but the build was crap. the thing blew more tubes than a prostitute. never figured out what was wrong with it, and once i got my engl, i never really cared to. sold it on craigslist for $800 cash lol

while i never personally encountered your particular problem, i have heard of its prevalence among 6505+ users. it'd probably be best to take it to a pro to diagnose as the problem may not necessarily be (just) the ribbon cable itself, but the regulation of power that flows through it.
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Oh and after talking to the tech he said it was most likely bad wiring in my apartment that did it. It worked fine one night, the next morning it wouldn't turn on. He said the bad wiring probably caused a short and made that small burn. Since the tubes and fuses aren't bad he said the transformers should be fine.
 
I've had a ribbon cable burn in a 5150 a couple years back. Contact Peavey Parts Dept. to get another one or do what I did and have your tech hardwire the connections!
 
You need to check the capacitors that control the heaters for your tubes. One of them might be bad and is allowing DC current through. Seems to be a recently common thing. I SERIOUSLY doubt that the wiring in your apartment had anything to do with it. Also you need to replace your tubes after something like that. Could be a bad tube that shot some electricity back down the wire. If it did that it might have hit the caps too. Check them out for sure and get some new tubes and ribbon cable.

-Alex
 
that's a hi- resistance connection. it can happen. The connection, either the male-female or ribbon-header, causes a hi-resistance point and heats up.

contact Peavey and ask for a replacement. I've fixed this issue on $3K+ amps. Also, check the PCB post for possible pitting.
 
Any idea how much this cable goes for? I called and guess it was past closing time so I'll call tomorrow. I took the connector off and the board is clean so hopefully it's fine. The prong is a tiny corroded but not black or anything, just very slight. Don't know if light sandpaper or anything is safe to clean it up.
 
Call Peavey for a new cable. You'll want to touch up the solder joints on both circuit boards as they usually are affected when this happens. If the pins that the cables connect to are burned they should be replaced too or it will happen again to the new cable. It doesn't look like it got that bad to affect the pins from the pics.
Jerry
 
Take the caps out and put them in a capacitor tester. You can also take them out and use ur multimeter in the ohm testing range and connect the positive and negative leads to the positive and negative on the cap and see if it charges. if it immediately maxes or doesn't charge it's bad. But thats a really shitty way to test and will only show if the cap is completely shot. Be sure to discharge the cap before you do it as well. and be safe. there can be alot of juice in those bad boys and can do some pretty serious damage to your hand and possibly kill you.

Most of the time you can tell the cap is bad by just looking at it. If it's swollen or leaking.

Could very well be a corrosion problem too. Seems to happen with ribbon cables alot. Be sure to clean the area well. Carbon is conductive. Idk how proper it is but i use rubbing alcohol and a q-tip to clean stuff like that.


-Alex
 
Thanks again guys.

Jerry, I emailed you a few days ago going much deeper into this whenever you get a chance to read it. Depending on how much damage there is I may just send it to you and get it modded at the same time and keep it. If it's something small like just the cable or something then I'll probably just fix it and sell it.
 
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