Thanks for tips so far

Yesterday i did measure some voltages from power supply (pcb03). While measuring microcomputer (pcb04) was disconnected. I made mistake by shorting 5v to ground (i think) and that blow fuse 1. So now i do not have 5v... I noticed that D28 was replaced with two other kind diodes in series. That might be ok, but i will change right diode in future. Also TR18 was changed to BD244C (original was BD534). The new transistor maybe ok, but should i change it by original type transistor? After i get 5v back i can continue measuring. Without 5v and microcomputer board attached 30v part of psu do not start and those voltages cannot be measured.

Tane

tane wrote:

Also TR18 was changed to BD244C (original was BD534). The new transistor maybe ok, but should i change it by original type transistor?

No, this BD244 can even stand a little higher voltage (100 instead of 60) but that is a level, that would never be reached. The diode should be a 5.6V Zener-diode. If there are two in series, the voltages have to be added. But it is not rally needed for a proper function. It is a over-voltage-protection to blow the fuse, when the voltage exceeds that level.

Chris

Hi

Today I got new fuse (F1) and BM has now 5v again. I noticed that 30V circuit does not start. Unit is still showing "COdE", i think that RL1 is off in this state.

Also noticed that 50/60hz signal is not visible after TR19 (red). It can be seen from resistor R114 (yellow). If i understand correctly this hz signal is used By RAM for timer. Should that signal be possible to measure after TR19?

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Tane

Hi,

yes, the relays are not powered, when they switch on (active in stand-by)! That is annoying me too.

You are right, the 50 Hz should be measured. If there is no high level, the transistor is possibly short. Try with a ohmmeter to ground. When you desolder the transistor or only the collector, the 5V should be there (at the joint). It's coming from pcb4 via a pull-up resistor. (Diagram D, connection C42). If so, change the transistor.

Chris

Thank you!!

The „Radio“-thing was my Solution!!