Technics RS 9900 Tape Deck right channel not working.

[Hansman]

Hello, i got a Technics RS 9900 Tape Transport with Reproduce Amplifier.

My Problem is, in Playback only the left channel is working.

I looked at the voltages of all the Transistors in the PB Head input region..

L-Channel:
TR201 C=12,91 B=13,25 E=15,5
TR203 C=9,79 B=13,28 E=13,78
TR205 C=0,0 B=9,81 E=10,44
TR207 C=0,0 B=0,737 E=0,0

R-Channel:
TR202 C=4,4 B=0,0 E=4,38
TR204 C=5,0 B=4,35 E=5,0
TR206 C=0,0 B=4,99 E=5,64
TR208 C=0,0 B=0,742 E=0,0





Maybe someone can help me with this.
Thanks

 

[swechsler]

Did you confirm you have a signal coming off the head? How about through the interconnect cable?

Start with the simple stuff first. This is a pretty rare deck and it's unlikely that someone here will have troubleshooting experience with it.

 

[Hansman]

Yes, i connected the PB Head R to the L Input, and it worked.
The PB Head is working fine.

 

[elnaldo]

Can you post a link to the schematic?

It looks like tr 202 and 204 are shorted from B to E. The other channel has a different voltage at B and E. And the bad channel is not receiving the proper supply voltage. It could be the short dropping the PS voltage, or a short already blew a resistor or other part, interrupting the PS voltage. But the Emitters are receiving just 5 V when the good channel gets 15, 14 and 10V

But we need a schematic to confirm what's happening and what to check.

 

[Hansman]

Today I fixed the issue, i had a shorted Tantalum Capacitor C204.
I changed the part, now everything works fine.

Thanks for your help!