newbie needs help with 9090db

audihaun

New Member
i'm new here, my Name is thomas, living in Germany. I've got a 9090db which didn't go out of protection mode (red light blinking). With the help of Infos from this site i already changed 2 resistors on the Driver board - green light now and the relay is klicking ! :banana: So far so good. But no Sound at all.
Turning all knobs don't produce even any crackles , just dead :tears: .
I connected another sansui pre-amp to main in and it's working, but a few crackles are audible in low passages. What next ?

i own some other sansui devices in fine condition:
QRX-3500
B-2101 and C-2101
SE-8
combined with Revox Symbol B MK1 or Revox Emporium Speakers :music:

thanx for any help
 
Do you have the schematic? Do you have a digital voltmeter, and know how to use it ?
Any " history " about the amp?

Welcome Thomas~

Mike
 
i have a schematic and a Voltmeter yes (analog not digital).
I can use it if somebody rells me how to :yes:

there is not much (known) history. A friend of mine bought it many years ago and stored it. He doesn't even remember exactly what was wrong then.
I got the device, cleaned evrything as good as possible, did a first try with Deoxit on most Switches etc.. then started to get it out of protection mode, with which i succeeded :thmbsp:
wooden case and front are in excellent conditions, all knobs and Odds are there they should be and i would really like to get it back to working condition.
 
Hi Audihaun, welcome to AudioKarma. You have joined a very long list of AK members that were drawn here by a protection light on a 9090DB. Before getting into testing check to see if the switches are set properly. Be sure the knobs are installed correctly so the pointers are pointing to the correct function. In particular check the speaker selector. If only one set of speakers are connected you will not get sound output if the speaker selector is in the A+B or any other combination of two speaker sets.

Also check to see if the jumpers on the back panel are correctly installed between the pre-out and main in terminals. Also be sure your speaker wires are connected correctly.

- Pete
 
Hi,
would be helpful if someone gives me a hint how to test the Signal on Grey/blue cables with a Volt/Amperemeter. I think i have to connect to +/- of a channel but how to select the meter ? DC Volt, AC Volt, Ampere ?
 
It's not your problem but if you want to measure it, set the meter to DC voltage and measure between each of those wires and the metal chassis. When you do this, you are measuring DC offset. It should be below about 10mv.

Check the things I mentioned in post #5 first.

- Pete
 
Hooray

:banana::banana::banana::banana: I cleaned all Switches, replaced the preout/mainin-bridge with a chinch cable, set all controls as they should be set and what ? :music:

as far as my humble ears can say, the 9090DB is working fine ! :thmbsp:

I'll enjoy some reward,now :smoke:

thank you for your reponses
 
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