Beolab Penta restoration help

[MaddyMorphosis]

Hey beoworld,

I recently got a set of Beolab Penta’s 6601. After trying them out one of them gave an amber light and the other produced audio but got hot extremely quickly. I’ve mostly disassembled the amps and nothing appears broken. At this point I have some questions for this community before I can continue to repair them. Feel free to help out on any question. All help is appreciated!

1. For the amps I’m planning on getting the amplifier service kit from Beoparts-shop (now: Danish Sound Parts). https://www.dksoundparts.com/product/beolab-penta-amplifier-capacitor-and-service-kit/ Does it include new thermal paste or will I have to get my own? Any other advice for this kit?
2. I’m not sure if I should get replacement power supply capacitors. One of the amps has a very slight bulge on the capacitor, but that was the unit that was still working so I’m not sure if that’s necessary. https://www.beoparts-shop.com/product/beolab-penta-filter-capacitors-for-amplifier-power-supply/
3. When disassembling the speakers themselves I could not get one of the crossover boards out at all. Unlike the other ones this one is completely stuck. Any advice for getting it out? I don’t have to take them out if I’m not replacing parts on the boards but this set is from 1987 so I’m not sure if any of the capacitors are up to spec. Although It wasn’t used much and they all look fine visually. Will replacing caps on the crossover be noticeable at all in sound quality? Also, on Beoparts-shop, they have two different crossover kits for different models. But I can’t find a serial code anywhere. Anyone know where to find it?
4. The midranges have heavy foam rot so I’m going to get a kit to replace those with rubber. Any recommendations for what kit to get?
5. The bottom subwoofers on one of the speakers doesn’t move properly. It barely vibrates when making sound and when pushing it in I can feel resistance and a scraping. Anyone know what might be wrong here?
6. Every subwoofer appears to be leaking some kind of hardened resin like substance from the dust cap. No idea what it could be. Don’t worry about the dust caps being collapsed. According to other people here its only visual and I’m planning to use the covers for the speakers.
7. And last, The fabric covers have become brown-ish. The person that used to own these smoked inside. They also ripped slightly in the corners. Any options for replacing, or at least cleaning these?

Thanks in advance for any help

• This topic was modified 1 week, 2 days ago by Dillen.

[Dillen]

1,
The kit description does not mentioned thermal paste, so it is not included.
The thermal paste rarely needs attention in these models, but if you must replace it I suggest you
get some of the good old white stuff. The newer grey stuff dries out very fast and is useless.
This guy made a great video:
https://www.youtube.com/watch?v=psY_RV1NjHM

2,
A bulge points to internal overpressure. Replace them!

3,
Electrolytic capacitors from 1987 are no longer up to spec. That’s fairly safe to assume.
The boards can bind immensely. Pull and wiggle and it will come out.
Look at the back of the boards and compare the numbers there to those mentioned in the kits descriptions at Danish Sound Parts.
https://www.dksoundparts.com/product/crossover-capacitor-kit-beovox-beolab-penta-early-version/
https://www.dksoundparts.com/product/crossover-capacitor-kit-beovox-beolab-penta/

5,
A rubbing woofer must be replaced. Look at f.e. Ebay for a good original one.

6,
It’s glue. It holds the thin wires running from the flex wires to the voice coil.

Don’t get me wrong, but are you sure you have enough experience to do this?

Martin

• This reply was modified 1 week, 2 days ago by Dillen.

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