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matsj
12-30-2007, 11:59 AM
I bought a 6230 amp and i just have a question about it: After i push the on button it takes 3 minutes for the amp to start to play. The standby lamp works and is on for 3 min and then the amp clicks and standby is off and the amp plays. Is this normal for it to take 3 min or ?

I think the amp is 17 years old and i opened it for a look and there is NO dust inside it, perfectly clean. It has been installed so there are no scratches on the front and it looks like new.

Happy new year, mats

johnaec
12-30-2007, 01:33 PM
'Doesn't sound normal to me. I've got a both 6260 and 6215 here, (same series), and both are almost instantly on - I hear the relay click within about 3 seconds.

John

SMKSoundPro
12-30-2007, 03:16 PM
I have a UREI 6230 that exhibited the same problem.

There is a capacitor that sits in very close proximity to the very warm voltage regulator devices. Most of these amps come from fixed install and have spent many hours on. That heat builds and shortens the life of these two caps, preventing the amp from energizing the relay.

I wrote to Zilch, and he explained exactly what caps they were and to simply change them. I further upon his advice, mounted the two new electrolytic caps to the trace side of the printed circuit board to keep the problem from re-occurring.

Once I did this very simple repair, the amp turns on within a couple of seconds and sings and swings like a crooner!:applaud:

I will see if I can find the schematic or email from Mr. Zilch to help you reference the cap number.

Scott.

SMKSoundPro
12-30-2007, 03:21 PM
Dear matsj,

Here is the copy of the email with the pertainent info. It is a really simple fix!!!


Scott.



Re: UREI 6230
Manual w/schematic is here:

http://www.jblproservice.com/pdf/Vin...6260manual.pdf (http://www.jblproservice.com/pdf/Vintage%20JBL-UREI%20Electronics/JBL-6230_%206260manual.pdf)

Same symptom. Look at the +/- 15V supplies on an oscilloscope. If there's much ripple, replace C28 and C30. I just bought them at Radio Shack.

I don't remember any resistor thing right now....

Zilch

Quote:
Originally Posted by SMKSoundPro
Dear Mr. Z,

I just received a UREI 6230 that is experiencing some odd behavior.

I replaced the on-off switch because the neon lamp was out. Everything fine.

I have it hokked up out in the main room with the L200b's. When I power it up, it stays in standby mode.

All wiring in and out of the amp is appropriate. I make sure that no signal is being sent to the amp, in other words all pots from the preamp are turned down.

This amp was a gift from a JBL friend that had taken it out of the Valdez Civic center for servicing.

I dont have a scheme, just my own experience with pro amps to go by. I searched the forum and found that you use a 6230 & 6260, and that you changed the caps on the regulator circuit, and something else about 1 watt to 5 watt resistors somewhere.

Can you help?

Thank you in advance!

Scott M. Koeller

matsj
12-30-2007, 11:53 PM
Thanks for the answers. Iīll check these caps.

mats

matsj
12-31-2007, 02:01 PM
Is there a simple upgrade that i can do to make it better ? Subwoof any thoughts ?

mats

JBL Dog
01-03-2008, 11:52 AM
I bought a 6230 amp and i just have a question about it: After i push the on button it takes 3 minutes for the amp to start to play. The standby lamp works and is on for 3 min and then the amp clicks and standby is off and the amp plays. Is this normal for it to take 3 min or ?

I think the amp is 17 years old and i opened it for a look and there is NO dust inside it, perfectly clean. It has been installed so there are no scratches on the front and it looks like new.

Happy new year, mats

mats:

I use a 6230 and a 6290 to bi-amp 4343's. The 6230 is up and running about 2 seconds before the 6290.

Roverbo
02-16-2014, 12:21 PM
I bought a 6230 amp and i just have a question about it: After i push the on button it takes 3 minutes for the amp to start to play. The standby lamp works and is on for 3 min and then the amp clicks and standby is off and the amp plays. Is this normal for it to take 3 min or ?

I think the amp is 17 years old and i opened it for a look and there is NO dust inside it, perfectly clean. It has been installed so there are no scratches on the front and it looks like new.

Happy new year, mats

Hi Mats, a kind of a "late answer" for sure, but i had the same problem with my 6260, searched the net, and found this forum. So much interesting stuff in here...
You havenīt mentioned if your problem was solved, so... back to the topic: I soldered the mentioned caps out, new caps in; no changeat all!
Next step was to put a scope to the base of Q23 (the relay driver). There was some flickering before the relay was drawn. Also signs of hf oscillation around 1 MHz. My guess was problems of leak current from the caps around the schmit-trigger IC2C, and unstability in the 7815/7915 regulators. So i changed C35 and C13 to new caps, and soldered 100 nF micas on the back side of the pcb on C28 and C30.
Problem solved. I canīt tell if leaking caps or the oscillation (or both) was the cause.
Regards, Bo.

rlsound
01-31-2015, 10:19 PM
What would be the cause of a loud thump on power down?

We had an amp that went out during a show, got it repaired, and now makes a loud thump on the disconnection of AC at the end of the night. This amp did not thump on shut down before the service.


Is this the workings of K1??

Edit: It's an Urei 6230

NVGrampy
09-21-2018, 01:39 PM
I paid an "Authorized JBL Pro Repair Center" to "fix" the same problem in one of my 6260s. They recapped the low voltage supply. The amp ran "back to normal" through the warranty period. Then, it developed an un-listenable hum problem when connected to any signal source. It does not hum with nothing connected to the inputs. I would appreciate any thoughts or shared experiences.

grey
09-22-2018, 03:33 PM
I paid an "Authorized JBL Pro Repair Center" to "fix" the same problem in one of my 6260s. They recapped the low voltage supply. The amp ran "back to normal" through the warranty period. Then, it developed an un-listenable hum problem when connected to any signal source. It does not hum with nothing connected to the inputs. I would appreciate any thoughts or shared experiences.

Try some deoxit. I use a soaked pipe cleaner on the XLR inputs and a swab on the TRS inputs. Deoxit the cable contacts as well and/or try known good cables. If you have a metal rack, remove it while you're troubleshooting.