General Forum

Re: Problems with Beomaster8000 - low output, and goes into clipping immediately

BillinMichigan — Mon, 05 Jan 2009 20:51:53 GMT

Thanks for everyone's reply. I don't feel anywhere near as alone in this as I once did. That in and of itself is helpful.

I had taken it to an authorized B&O servicecenter (in Detroit) and they quoted $300 to fix it. I got cold feet and thought I'd take a shot at it. When nothing jumped out at me (no obvious faults - such as the ones you mentioned), I stopped pretty much right there. I have an EET degree from Michigan Technological University so I have some idea on what I'm doing but that was 18yrs ago and my soldering skills leave something to be desired at this point. I think I need a new iron and solder too. Anyway, I recently bought a sig gen now all I need is an o-scope. I was looking at handheld verisons for about $150-250. Do you think this will be good enough?

The unit is in an unknown state right now. I'll have to get it out and dust it off (literally) and get back with you. What did you mean when you stated "service mode". I assume you mean with it apart yet connected to operate. If you wouldn't mind, I'd like to call when I get to that point - if you'd be OK with this call my cell phone at 517-414-2475. Thanks again for the assist and the pep talk.

Bill.

Re: Problems with Beomaster8000 - low output, and goes into clipping immediately

Friedmett — Thu, 01 Jan 2009 19:03:09 GMT

Yeah very nice to see it in one place.

My white edition 6000 system and rosewood 8000 system are placed in the same room but one in each end.

The 6000 consist of BG6006, BC6000 and BM6000 on original white SC60 stand with the 2 pairs of white Beovox S80.2 and S120 in front. Not ideal speaker placement but it works great.

The 8000 consist of BG8002, BC9000 and BM8000. BM and BG are placed on a white Atycca II stand while the BC and CDX are placed other wise like the computer case or on my DAT player in the window. 1 pair of Beovox M150 completes that system

In the middle I have my Beovision LX5500 with electric floorstand and a VX7000 2 way model.

That's the main stuff anyway. I got extra B&O too mostly comming from getting the 8000 system together or the time before.

To topic I would say that you should get hold of Dillen here. He is the guy that got my Beomaster 8000 back together. It was blowing fuses and full of loose connections. It's always worth fixing it and you came to the right place.

Re: Problems with Beomaster8000 - low output, and goes into clipping immediately

j0hnbarker — Thu, 01 Jan 2009 14:44:31 GMT

Nice photo Geoff!

I have everything shown in my collection, with the exception of the Beocenter. I have a BM 8000 in my living room with a Beogram 4002, Beogram CDX, and Beovox Pentas. In one of my spare rooms upstairs I have a full Beosystem 6000 (BM 6000, BG 8002, BC8004 and MC120.2s) plus a Beogram CDX2, and in the main bedroom a full Beosystem 5000 with some CX50s and a Cona. I have never had them all together though in the same room at once like you have - that must be a pretty big display unit you have there :)

Re: Problems with Beomaster8000 - low output, and goes into clipping immediately

geearr — Wed, 31 Dec 2008 22:42:55 GMT

Hi Bill

It sounds as if you have a lot of work ahead if you are going to fix both the BM8000 and 6000. They are fairly complex units but I have also been able to take non working units and get them functioning brilliantly once again so it can be done. I have recently finished my BM8000 and it now takes centre stage in my collection. See photo taken last week.

For such a complex topic, your questions are a bit vague but I can try and help as follows:

Do you need a scope and signal generator? The answer is sometimes and depends on what is wrong. In many cases, you can get away without but you must have access to a fairly good multimeter. I have access to both the scope and the sig gen and for me, they have been worth their weight in gold.

With regard to what fails, Craig has already mentioned that a capacitor replacement is probably inevitable but again, it has its limits. I have just replaced about 60 in the 8000 and the improvement has not really been noticeable. However, that doesn’t mean to say that the electronics aren’t performing better and they probably are. Thereafter, the problems can be related to faulty trimpots and even burnt out resistors and transistors.

In order to get everything functioning properly once again, you will probably have to dismantle and reassembly the unit several times. If you are comfortable with all of that and you have good soldering skills then you might have some fun with this project. As I mentioned, I dismantled mine almost completely, and I have many photos, notes and assembly points that might help you. Even the removal of the layers of dust and muck can go a long way towards getting it to function again. I gave mine a thorough clean and even spray painted some of the more rusty and grotty looking items. I think my unit was taken apart and reassembled about four times and in the end you do become very quick and proficient.

Before you start dismantling, you will need to understand the present condition of the unit. I am not sure in what condition your unit is, and presumably it is fully assembled and ready for startup. If it is, I would first disconnect the speakers and everything from the socket panel before powering up and then switch in using Tape 1. Listen for the two relay clicks and note the volume setting that is indicated on the panel. If it comes in high, quickly turn the volume down to zero and see if the unit does or doesn’t trip. Which lights are on and does the clipping indication still show if the volume setting is low? If the unit is able to power up without tripping, leave it for a while and sniff around for burning smells and hot spots. If anything is getting too hot, switch off immediately. This would be a good starting points and the next step would be to repeat the same operation while the box is open and everything is in service mode.

That is all that I can suggest at the moment. If you can clarify what happens under these conditions, it would be a great help and then you would be in a better position to sort out the real problems that you are dealing with.

Regards

Geoff

Re: Problems with Beomaster8000 - low output, and goes into clipping immediately

Craig — Wed, 31 Dec 2008 07:56:50 GMT

Probably needs the Caps replacing. One of our members Martin (Dillen) should do a full cap kit.

Craig

Problems with Beomaster8000 - low output, and goes into clipping immediately

BillinMichigan — Tue, 30 Dec 2008 22:40:34 GMT

Hi,

I have had this unit for several years and it actually has been apart in my basement for the past two. Questions: do I have to have an oscilloscope/signal generator to fix this? Does anyone have any advice on what typically fails, how this amp functions, what to look for, what to avoid, what specifically not to do, etc. Any help would be great and hopefully energizes me to get it fixed and enjoy it. I also bought a Beomaster6000 at about the same time with a similiar problem. Thanks. Bill.