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Genz Benz Streamliner 900... blue interior light out....

#84
I just replaced the LED's and cleaned the potentiometers in my Streamliner 900 and made an illustrated guide on how I did it. I'm not a pro, but it works flawlessly. It's on this site:

Link Removed
 
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#86
I'm cross-posting this from the other thread... to reinforce why I recommend a qualified, experienced tech to do the repair. There is no reason whatsoever to disassemble the amp at all (other than remove the tubes). There's the correct way to do the repair and there's the hard way to do the repair, an experienced tech will do it the easy way and charge accordingly (hopefully). It's not really a DIY type repair, but it can be done. You can also turn a perfectly good amplifier into a mess...

Ugh... nice attempt and a really nice presentation but a couple of really serious and potentially catastrophic errors here.

1. NEVER test an LED directly across a 9V battery, it's likely to damage the die. The current must be limited to less than 20mA to prevent damage, which might not show up for a while. If you look closely, you will see that the package has a flat side which aligns with the flat side of the silk screen.

2. Do not use solder braid on double sided boards with plated through holes. If you have a really light touch it might be ok, but the approved method is to remove the LEDs and clear the holes with a mechanical/vacuum solder sucker. Even though these are really rugged PCBs, it's easy to damage the pads and through hole plating with braid.

3. With the DeOxit, only a TINY TINY amount is necessary. More can lead to premature failure from washing lubricant to places it should not be, and attracting dirt down the road.

4. There is no reason whatsoever to remove the PCB from the chassis. The entire operation can be performed from the top in about 3 minutes from start to finish without any risk of damaging anything else.

5. There is ~350 volts present all over the inside of the chassis, be absolutely sure the HV (high voltage) bus is discharged... removing wiring/connectors can remove safety bleeders. Always measure before sticking your hands anywhere inside an amp like this.
 
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#87
agedhorse said:
I'm cross-posting this from the other thread... to reinforce why I recommend a qualified, experienced tech to do the repair. There is no reason whatsoever to disassemble the amp at all (other than remove the tubes). There's the correct way to do the repair and there's the hard way to do the repair, an experienced tech will do it the easy way and charge accordingly (hopefully). It's not really a DIY type repair, but it can be done. You can also turn a perfectly good amplifier into a mess...

Ugh... nice attempt and a really nice presentation but a couple of really serious and potentially catastrophic errors here.

1. NEVER test an LED directly across a 9V battery, it's likely to damage the die. The current must be limited to less than 20mA to prevent damage, which might not show up for a while. If you look closely, you will see that the package has a flat side which aligns with the flat side of the silk screen.

2. Do not use solder braid on double sided boards with plated through holes. If you have a really light touch it might be ok, but the approved method is to remove the LEDs and clear the holes with a mechanical/vacuum solder sucker. Even though these are really rugged PCBs, it's easy to damage the pads and through hole plating with braid.

3. With the DeOxit, only a TINY TINY amount is necessary. More can lead to premature failure from washing lubricant to places it should not be, and attracting dirt down the road.

4. There is no reason whatsoever to remove the PCB from the chassis. The entire operation can be performed from the top in about 3 minutes from start to finish without any risk of damaging anything else.

5. There is ~350 volts present all over the inside of the chassis, be absolutely sure the HV (high voltage) bus is discharged... removing wiring/connectors can remove safety bleeders. Always measure before sticking your hands anywhere inside an amp like this.
Click to expand...
And so... my love for this amp and it's people has grown even more! :)
 
#89
agedhorse said:
I'm cross-posting this from the other thread... to reinforce why I recommend a qualified, experienced tech to do the repair. There is no reason whatsoever to disassemble the amp at all (other than remove the tubes). There's the correct way to do the repair and there's the hard way to do the repair, an experienced tech will do it the easy way and charge accordingly (hopefully). It's not really a DIY type repair, but it can be done. You can also turn a perfectly good amplifier into a mess...

Ugh... nice attempt and a really nice presentation but a couple of really serious and potentially catastrophic errors here.

1. NEVER test an LED directly across a 9V battery, it's likely to damage the die. The current must be limited to less than 20mA to prevent damage, which might not show up for a while. If you look closely, you will see that the package has a flat side which aligns with the flat side of the silk screen.

2. Do not use solder braid on double sided boards with plated through holes. If you have a really light touch it might be ok, but the approved method is to remove the LEDs and clear the holes with a mechanical/vacuum solder sucker. Even though these are really rugged PCBs, it's easy to damage the pads and through hole plating with braid.

3. With the DeOxit, only a TINY TINY amount is necessary. More can lead to premature failure from washing lubricant to places it should not be, and attracting dirt down the road.

4. There is no reason whatsoever to remove the PCB from the chassis. The entire operation can be performed from the top in about 3 minutes from start to finish without any risk of damaging anything else.

5. There is ~350 volts present all over the inside of the chassis, be absolutely sure the HV (high voltage) bus is discharged... removing wiring/connectors can remove safety bleeders. Always measure before sticking your hands anywhere inside an amp like this.
Click to expand...

Thanks, but..."attempt"? I'm pretty sure that word is used to describe a failed job, so I'll just assume you chose the wrong words there. I've played 2 shows and had 2 rehearsals since then without so much as a minor a minor glitch. It was done at a cost of pennies (a few inches of braid, a few squirts of DeoxIT, and some electricity for the iron). No mess...so far. I already calculated the risk. It's out of warranty, so in the worse case scenario, I learn something and have to pay to have someone to repair it as I would have to anyway, but that didn't happen. It took me a little over an hour while taking pictures, unless you want to consider the 3 days it sat unpluged. After working on numerous smartphones, laptops, tablets, PC's, amps, appliances, automobiles, cannons (the ones that go boom), plumbing, electrical, etc in my time, the "hard way" of removing the board was not rocket science for me and an absolute necessity with the tools I had on hand. I'm not insinuating that it's something everyone will want to do themselves, but, as you know, people will, and if no one is going to offer a method for them, then I figured I would start one.

Regarding the list of "potentially catastrophic errors here." I don't mean to be defensive, but I think I need to respond, based on the fact that I have addressed some of the items as per your criticisms (always welcome) and it seems you are making insinuations that are inaccurate of my approach regarding the cleaning of pots, that I wouldn't want people to assume of my method should they read your remarks...

1.) Duly noted. I got lucky...so far (too many times over the years to learn that lesson I guess). LED base shape and silkscreen notes have been added to establish proper polarity.
2.) "Do not use (de-)solder braid on double sided boards"....unless all you have is braid, time, and are experienced with it. Someday I'll get a vac desolder station within my budget, but I do this work so few and far between that at this time, I can't justify the expense of a new one.
3.) True...but I never insinuated that you spray it down like it's on fire.
4.) There is a reason....personal preference given the tools at hand. Braid won't pull the solder through the board from one side effectively. I also get to see the build. I'd never argue that a de-soldering vac/sucker isn't the absolute best way to go, it's just not the only way if you have experience. For those that would try this...the braid works great if you fray the end and poke it into the plated through hole. It will wick it right up, but when it stops, remove the heat and braid and cut a fresh end of braid and repeat until the hole opens up enough to get the new LED lead through. You could probably use the existing solder in the joint, but I am weary of this since re-use of solder has lead to cold-solder joints in my experience and I like to use fresh solder as much as possible.
4.5) "The entire operation can be performed from the top in about 3 minutes from start to finish without any risk of damaging anything else." ...so, while you want a $75.00 flat rate plus shipping both ways outside of my state with a turn around time far greater than doing it myself, I have a cost of practically nothing and can get it done pretty quickly. Others may come to the same conclusion I did and decide to wait till they have a real problem or create one by accident to justify the expense.
5) So true...I thought mentioning that it has been unplugged and the power rocker switch on for several days (capacitors drain much more quickly than this) was enough to eliminate that as a concern, but that's too assumptive on my part, so I added notes on that for potential skimmers. I agree that it is a responsibility to elaborate on the danger and importance of testing rather than assume it is known. I would say this should be the first thing to consider as a concern and I may add a special disclaimer section ahead of the steps when I have more time.

So yup...this job is best done by a professional with the right tools, experience and know-how, no doubt, but it can be done otherwise if you have a few tools, some experience, take caution, pay attention, and aren't afraid.
 
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#90
Another cross-post:

@odic, I was not insinuating anything. When you prepare a "repair guide" (your words in the title of this thread not mine), IMO you have the obligation to present accurate information including safety information since there will undoubtedly be folks who will try it on their own. You can not assume that folks attempting this understand that there is >350 volts present throughout the amp (in some areas 450 volts) and that it does present a danger to somebody who is unaware of such dangers.

Solder braid is not a good choice for working on double sided PCBs with plated holed. It's quite possible to damage the PCB pads unless you are experienced with these techniques (takes more time than watching a video) which are not easily repairable... or repairable at all in any kind of reliable workmanship like manner. To suggest that folks try this is IMO a poor idea, and for those trying this on your own I will not be able to repair such damage. There are also no replacement preamp PCBs available as these parts are to be repaired by competent techs. To date, there have not been any repairable amps that have come through my shop (over a period of say 4 years). The proper tool is a solder sucker. Paliden makes a very nice extruded aluminum one for under $25, so cost is not at all a factor.

My offer to repair any Streamliner for $75 flat (not including power amp module or HVPSU module) plus return shipping includes everything that needs attention, I don't just replace LEDs without going through everything else and doing a full factory diagnostics/burn-in because in the event there are other issues how do you think a customer would feel getting a half-ass incompletely repaired amp returned to them? By doing a complete and thorough job, the complete repair is covered by warranty, and I know that I have done everything necessary to be sure the customer is getting an amp where everything works properly. Perhaps you misunderstood how this works?

I did like your presentation and photos very much though, I just cringe at the thought of getting PM's from folks who attempted the repair and damaged the PCB...

The proper repair method is:

-Remove from power source and let sit for a minimum of 5 minutes

-Remove top

-Meter HV bus to be sure DC voltage is less than 5 volts

-Remove tubes

-Remove LEDs

-Add drop of liquid flux and solder suck each of the 6 LED holes

-Trim new LEDs to length

-Note polarity via the flats on the package and the flats on the silk screen parts outline on pcb

-Install first LED with leads sticking 3mm into PCB and solder one lead, then the other (from the top)

-Install LED #2 and #3 is exactly the same way

-Clean top of PCB around LEDs with flux cleaner and Q-tip. Do not "wash PCB"

-Bend LED leads as needed to shine on tubes (remember how the old LEDs were positioned?)

-Reinstall tubes

-Reinstall top

-Test (if the LEDs don't work, it's almost certain that you screwed up one of the LED's direction)
 
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#91
Similar problem.

Lights work after amp has been on for an hour or so. I can then turn it off and they function normally until it cools, less than 20 minutes. Never gets more than warm to the touch (fan running).
 
#92
Dadagoboi said:
Similar problem.

Lights work after amp has been on for an hour or so. I can then turn it off and they function normally until it cools, less than 20 minutes. Never gets more than warm to the touch (fan running).
Click to expand...


The lights are cosmetic and this was a common problem. I believe they got a faulty batch of the LEDs, so it's not a problem with the design.

It's up to you to decide if you want them replaced. It's an easy job for a qualified tech.
 
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