Akai gx 630 defekt

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Antonello4923
Schaut ab und zu mal vorbei

#1 erstellt: 21. Okt 2021, 09:46

Hi friends I remind you again to help
I have an akai gx 630 which was given to me by a gentleman
but said he lit it and made white smoke
I tried it and it came out the white smoke was a 2sc945 transistor in the command board forward back play rec
I replaced the component and before turning on I gave a general check and I found the cause of the fault I think a capacitor with the polarity reversed on the relay board
I put the condenser back in the right position I turn on and nothing smokes anymore
so i thought now everything is fine
but is not so
I have two problems if I press forward play stop the functions are ok but if I press rewind it always starts forward practically does not rewind the reel
2 problem does not record the signal enters but does not record
so i should solve the rewind problem first
I checked all components on the relay board and they are still intact on the command board except for those small vertical resistors and impossible to check them one by one
the scheme is there but I don't understand much as being self-taught I don't have a great technical background

Ingor
Inventar

#2 erstellt: 23. Okt 2021, 11:14

The rewind button should do two things:
Fast forward relay is engaged
and rewind relay is enganged
If only the fast forward relay pulls on without the rewind relay the spindle spins always forward.
I marked the important circuits. You have to look there.
- Check the relay Does it pulled on?
- When it does, check the contacts an cabling.
- When it doesn`t check the circuit between the red marks.

The second problem is a totaly other thing.

When you record, does it erease the old recording on the tape?
When you push the source monitor switch to "source" is the input signal at the output?
Do the level meter swing?

Antonello4923
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#3 erstellt: 28. Okt 2021, 10:32

I answer on the second problem
the input signal feels good and the vu meters oscillate
... but I want to be able to fix the tape rewind and feed problem first
this morning turned it on and no longer even in advance
while it is in play if I press forward or rewind it goes to stop

Antonello4923
Schaut ab und zu mal vorbei

#4 erstellt: 28. Okt 2021, 16:15

update i replaced tr9 (2sc945) and now it works fast forward
I have yet to figure out what blocks the rewind
(tr9 was short)