[mexking]

Thank you Martin, will do

Its 5-6 years ago that I used my oscilloscope and I didn’t use it that much so I will have to get into learning again, not a problem but will take a little time

Found my old thread here

• This reply was modified 5 months, 1 week ago by mexking.

[mexking]

That didnt work, cleaned all properly and colocated the transistors again with new insulators and Thermal Paste in the left channel, and have the same failure. I have never had the same failure right and left, so I am a little lost where to start looking but as I never give up I will start checking from the preamps and onward

[mexking]

Getting ready to clean, doing one channel to see difference, the thermal grease feel soft and not dry to the touch. I didnt find the thermal grease that Martin recommend but had to buy the one for CPUs that he doesnt like. Just to test and then change it later when I find the right one, if this is the failure

[mexking]

Thank you Martin

I never thought of that, have been wondering the whole day, same failure left and right and no failures in the power feeds. Ordered new paste and will check on Monday. If this is the failure I may have other units with failures coming

[mexking]

Thank you Guy

I just checked US bay yesterday and there are a couple sold as spares that will probably be the solution, wrote Martin waiting for answer, he has a lot in his dungeon

Søren

[mexking]

Today slower than ever

[mexking]

Went in to check the power supplies, but before that I checked the idle current one more time, I connect my DMM and turn on, the idle current starts at 40 mV and increase to 150-160 within some 20 seconds right and left. I disconnected the power supply to the output amps P11 and P12 and started checking all the supplies 15,24 and 35 VDC all spot on give or take 0.1 VDC, but the USTB 35 VDC shows 38.5 VDC right and left channel. I did a big job restoring this unit some 10-12 years ago, had it working for a couple of years without problems, and as the search function in archived forums does not work I dont find my old thread about it. I am a bit lost here, will have to think about what to do.

[mexking]

Hola Eddie

This is going to take some time, I haven’t touched a B&O or an instrument for some 5 year

Good to see you

Søren

[mexking]

Hi Jacques good to see you again, a few of us still there

I will have to pack out my oscilloscope and get working again, but the BM 4400 is not the easiest to work on.

What I dont understand is why the overload circuit doesnt cut in

Søren

[mexking]

Search on the old forums worked like a charm

[mexking]

When going to Workbench forum in 2007-2012 archived no problems, when going to workbench 2012-2022 archived I get 404 failure

[mexking]

Here a pic from a 1900 with bad electrolytic caps, Get a set from Beoparts caps and lamps and you are good to go.

[mexking]

Went to my profile, could edit but not change avatar (Administrator only)

[mexking]

Going from here to Home getting the 404 error

[mexking]

the message with pic took some 4-5 min before it came up and now its there

[mexking]

Tested message with pic (300 Kb) shows up blank

[mexking]

Logging in I get the message Username or password incorrect shortly and then I get logged in anyway, testing pic, get back to the workbench

[mexking]

Mr. 10% took a couple of days lets see if it will work, cant log in but can post an answer

[mexking]

Check that the TA is not moving laterally at set down and lift of, I had that on one of my decks, dont remember which one.

[mexking]

 

Keep it original, you can get your cartridge repaired here https://www.tonabnehmerservice.de/ I have gotten repaired various SP and MMC s there, good service and quality work

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