speaker overload at low volumn on rockola 460
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Remove the Speakers and see if it still overloads.
Relist: Answer came too late.respond
disconected speakers one at a time found left front not to be working.
i removed 1 lead to each speaker still overloads i noticed that after removing lower base speaker leads that only right upper treble speaker works but sounds very weak and tinny
Check the ohm rating of each speaker. If there where there suppose to be, the amp is most likely back in it. There's removable transistors in the amp that get weak and overload over time. There should be 2 per channel and are screwed into the heatsink on the amp. replace them all at once and that should fix your problem.
this is a rockola # XXXXX a amp is this a job a novice could do /? what is the heatsink? where could i purchase the transistors?
It's not very hard to do. Just has to be done correctly. You'll need the replacement Transistors and thermal compound to reapply to it. The transistor's have to go in the same way they came out since the two pins are different. I'll need to know the part numbers off the transistors. There should be 4 of them total and 2 per channel. Both Channels use the same 2 transistor types.
Left Channel: Sample1 and Sample 2.
Right Channel: Sample 1 and Sample 2.
The Transistors look like this:
Let me know the part numbers and I'll locate the cheap replacements for you.
I dont see anything inside the amp that resemblesthe picture that you sent all components inside and behind the boards appear to be soldered anyway we could discuss this on phone? dennis XXXXXXXXXX
We're not allowed to communicate outside of this Q&A Thread my friend.
Can you take a picture of the inside and upload it here? Sometimes those transistors are hidden by a sliding cover.
sorry dont have the ability to send picture inside the amp there is a lift off cover marked left channel right chanel behind that is the circuit boards which are clipped in over a piece of cardboard which covers numerous soldered components.
I'm trying to locate a picture of the internals of that amp, but not having much luck since very few of them survived the years. I've worked on 100's from that time frame and they all had those style transistors. I'll attempt to continue searching for a picture to better help you on this unless you have an Electronic Repair shop nearby that can point the Audio Output Transistors to you. It should take them all of a minute to do so. From there, you can give me there part numbers and I'll locate the replacements for you.
are you convinced its a transitor problem? why the one dead speaker?should both speaker leads be removed to test overload condition?
These systems use crossover's that make the standards of normal speaker wiring completely different than the norm. What was the ohm reading from each speaker? If one reads a near short than that can cause the overload to trip red. Let me know what each speakers ohm ratings are by using a multi-meter.
I HAVE A SPERRY MULTIMETER what setting what should it read? touch meter leads to speaker terminals or wire leads?
meter set at 200 readings both 12 inch; 5.8 left side 6 inch:16.1 right side 6 inch 10.1
200 OHM setting is ok. We have to test them out of circuit so remove one of the speaker wires on all speakers then test them. Otherwise, we'll be getting false readings from the crossover and amp circuits.
I did have 1 wire removed when tested
Ok, look on the back of each speaker. It will tell you what Ohm Rating they are. i.e. 6Ω, 12Ω, 16Ω, etc. What are they?41098.8619111921
no ohm rateing only part # XX inch are original manual says 8 ohm l.s. 6 inch original manual says 16 ohm r.s. 6 inch replacement differant part#
Ok, all of them are reading good except for the 10.1. Disconnect that one and see if it continues to overload.
still overloads with both leads off all speakers when all hooked up no sound out of left 6" and very little tinny sound out of right 6"
did you recieve my last reply?
Sorry for the delay. Yeah, the amp's needs work done on it. It's not the Speakers or Crossover's. If you can get me the numbers on the transistors, I can help you order them.
I will send pictures a.s.a.p. may be a couple days is that O.K.
Sounds great. You can send them to email@example.com and they will forward them to me. Let them know that it's for Carl L.
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Just sent the pics in an email to XXXXX@XXXXXX.XXX attn Carl L
Ok, I'll let you know when I receive them. Haven't gotten them as of yet.