roland tr 606 not working with Power supply

[cutoffres]

Hi ! i think it's the good forum to ask this :

My TR606 has stoped to work when used with a non-original power supply , but my tr606 works good with battery .
I think the transistor B647 c do not work anymore .
My question is :
Will it work again with the original power supply , if i put a new B647 c transistor ? Or will have i to change other parts ?

Thanks

[schmidtc]

Why do you think it's that transistor? Did you check the voltages coming from the supply with nothing plugged in? If that's dead just get a new boss supply.

[magnus]

Are you sure it's not the power supply? Is it 9v dc negative centre with the right sized head?

[masyst]

I have the excact same problem with my Boss DR-110, but it won't work with a original power supply neither.
Could be because when I got it I tried to use it with a non-original adapter, and tried to use it with both plus in centre and minus in centre because it didn't stood anything on it on wich way it should have. So I may have destroyed it.
Work fine with battery.

Would love to hear if you get it to work, and what you have to do...

[LesDeuxLoveOrchestra]

does it light up, but just not run? mine did that when i had the reversed tip/sleeve config.

[cutoffres]

Hello . i ask again my question :

My TR606 has stoped to work when used with a non-original power supply . Now my tr606 works good with battery , but don't works with PSU
I was thinking that the transistor B647 c do not work anymore , but it seems to work (not sure).
Is there a man (or a woman) who can read shematics and would know wich parts could be responsible for that fault ?
Schema : http://machines.hyperreal.org/manufactu ... chem-6.gif
And : http://machines.hyperreal.org/manufactu ... chematics/

Thanks for the time you will take

[masyst]

Could it be the Resistor that are connected to transistor B647, that resistor described as fuse?

[Altitude]

2sb647 is the big green one IIRC. They dont make them anymore but they can be tracked down and I have read that there is a modern replacement that can be used also. This is a common problem when people use a poorly match external PSU for the 606 and 303 which ends up damaging the power circuitry. BEFORE you go replacing parts, find a proper PSU for it and test it. Either a regulated PSU or an unregulated one made for very low currents. The latter is VERY IMPORTANT. High current unregulated supplies will not produced the correct voltage when the current draw is very low (like in the 606), make sure you use one that is rated for 200 mA max or the proper Boss psu

[Steve Jones]

I would suspect a cracked solder joint on the power input, a power adaptor with a too large hole in the centre, or a faulty adaptor. looking at the schematic, the positive terminal of the battery follows exactly the same path as the positive sleeve input from the power adaptor, so R237 and Q41 must be OK. if there is a faulty transistor it would more likely be Q42.

[cutoffres]

Thanks to all of you for all your replies !
First i will get the proper boss PSU this week-end . And i will check the transistors ,if do not works with the proper PSU
I will let you know .
Thanks

[masyst]

I was on a synth-repair meeting this weekend and got help to my problem with the DR-110, and we found out that it was the transistor that was blown up when I used a non-original adaptor with it.
And I was told that this was a common problem when using non-original adaptors.
The transistor is there to change between batteries and adaptor when you plug the adaptor in.

[cutoffres]

masyst thank you for your answer .
according to you an Steve Jones my problem surely come From Q42 .

Q42 is a Power transistor B596 , could i replace it by a 2SC536 transistor ?
I should receive psu in the next days

Thank you

[masyst]

My power transistor (Q19) are called B647C.

But the basic if you can't find a transistor with the same name, try to find a transistor with almost the same specs as the one you already have.
More like the original, better it is...
But I think that the power transistor are not the most critical point to use a transistor with other specs.

Good luck!

[cutoffres]

Now it's OK ! The TR606 is working 100% with Power SUpply and with Battery .

Steve Jones was right , the faulty part was Q42 .

I hope it will help other members in the future .