Hello.
Integrated amplifier TECHNICS SU 8080.
No sound.
R329 blown.
After replacing...blown.
Need help.
Regards.
SM
TECHNICS SU-8080 SERVICE MANUAL Pdf Download | ManualsLib
Integrated amplifier TECHNICS SU 8080.
No sound.
R329 blown.
After replacing...blown.
Need help.
Regards.
SM
TECHNICS SU-8080 SERVICE MANUAL Pdf Download | ManualsLib
TR307 & TR308 are ok(desoldered and tested with tester) .
I noticed that the R343 also turned black.
I noticed that the R343 also turned black.
TR315 dead? It is a TR of a complementary pair of output of a channel, so you must consider that - probably - the protection has failed against some short circuit in the output terminals.
Check from back to front all the transistors and associated resistors, replace everything, put a lamp in series and from there it begins to check voltages.
The 2SA798 input differential pair was a very problematic double transistor and many faults can also be caused by the bursts it caused at the output. Unfortunately there is no test for them and no replacements are available, I hope I am not the culprit. But leave it for last, if the amplifier works well and then pops at times, you will have to build a differential pair with two common TRs.
Ok,thank you.
I was command 2 pairs of MJ21193 and MJ21194.
Left channel 2 power transistors are ok,but I want replaced all 4.
All rest transistors and resistors are OK.
I was command 2 pairs of MJ21193 and MJ21194.
Left channel 2 power transistors are ok,but I want replaced all 4.
All rest transistors and resistors are OK.
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If you plan to change all the output TRs, first try to make the faulty channel work well, (you will have to adjust quiescent current - bias -) and if everything goes well, then you can change the output TRs of the channel that works well. (you will have to adjust bias there too), it is almost impossible for the new TR to give the same IC (collector current) as the old ones .......
In service manual its 15mV.
Its for original transistors Toshiba .
If for MJ21193/94 it's the same IC?
Its for original transistors Toshiba .
If for MJ21193/94 it's the same IC?
Hello.
I replaced all parts.
Amplifier works fine.
Left channel IC 15mV.
Right channel IC 9mV max
I can't make 15mV.....
I replaced all parts.
Amplifier works fine.
Left channel IC 15mV.
Right channel IC 9mV max
I can't make 15mV.....
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What is the channel in which you cannot regulate the bias correctly? The one that did not work or the one that was operational?
If it is the faulty one, you should not have replaced the output TR of the channel that was operational, -as I already mentioned-, but you can still use it as a reference if the rail voltages are OK, to compare voltages and locate the component that still follows defective.
Depending on the circuit, you must have 0.4 Volts at the base of TR 311 and TR 312.
Control the components before the tuning preset.
If it is the faulty one, you should not have replaced the output TR of the channel that was operational, -as I already mentioned-, but you can still use it as a reference if the rail voltages are OK, to compare voltages and locate the component that still follows defective.
Depending on the circuit, you must have 0.4 Volts at the base of TR 311 and TR 312.
Control the components before the tuning preset.
I replaced 4 power transistors for symmetry of 2 Channels.
And now I can't adjust bias for right channel.
I turn potentiometer for bias for right channel (repaired),but no 15mV only 9mV max.
Left channel is ok,15.2 mV.
Amplifier works fine,no distortion,the level of 2 Channels is the same.
What components response for bias for right channel?
Thanks
And now I can't adjust bias for right channel.
I turn potentiometer for bias for right channel (repaired),but no 15mV only 9mV max.
Left channel is ok,15.2 mV.
Amplifier works fine,no distortion,the level of 2 Channels is the same.
What components response for bias for right channel?
Thanks
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All those associated with the driver - TR 312 -, perhaps the TW302 thermistor is faulty.
I see that you have specific instructions for essential controls in case of repairs on page 20, follow that to the letter. My English is very bad and I can't copy and paste the translator, sorry.
But surely English-speaking experts here will answer you.
I see that you have specific instructions for essential controls in case of repairs on page 20, follow that to the letter. My English is very bad and I can't copy and paste the translator, sorry.
But surely English-speaking experts here will answer you.