Trace the +18V from where it leaves the regulator board, and start disconnecting stuff until you find where that 123mA is going (0,5W @33 ohms = 4,06V / 123mA).
Do I understand correctly that the Volume motor drive still works EVEN WITH R245 open?
So some of those 8 traces that go off the page, bottom of page 6, only two of which have a signal name, are going to need sorting! 😉
Sorry, this is going to have to do it for me tonight (02:33 in the morning locally). Will check back first thing tomorrow.
Cheers
Do I understand correctly that the Volume motor drive still works EVEN WITH R245 open?
So some of those 8 traces that go off the page, bottom of page 6, only two of which have a signal name, are going to need sorting! 😉
Sorry, this is going to have to do it for me tonight (02:33 in the morning locally). Will check back first thing tomorrow.
Cheers
Any news yet on the destinations of those 8 traces that go off page 6 to the right?
A couple are labeled -- Trig and I/V -- but not sufficiently that I can sort it.😱
Regards
A couple are labeled -- Trig and I/V -- but not sufficiently that I can sort it.😱
Regards
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What is the hstory of c352? like, 2nd hand, droped, gived wrong voltage (220v or 110v). can you post a picture?
Did you solved +-50v supply voltage difference?
R245 in manuel 1/2 watt. Use 1watt? But, voltage over d119 must be near 18volt. Is it? If not you can control transistors there. Here +-18 volt supply for preamplificator. Preamplificator may be fault.
Did you solved +-50v supply voltage difference?
R245 in manuel 1/2 watt. Use 1watt? But, voltage over d119 must be near 18volt. Is it? If not you can control transistors there. Here +-18 volt supply for preamplificator. Preamplificator may be fault.
OK, if you aren't willing or able to trace the +18V power leaving the ±18V regulator section (as described in post 61 IIRC), let's start by unplugging the preamps. On the board with all the relays and input RCA's, locate M301 and M302 and unplug them. This will eliminate the preamps from drawing current. Then replace R245, again, and see if the regulators function.
Cheers
Cheers
How did you disconnect M301&M302 ???? they are on the board, not a port?
Do you sent a picture/photograph?
I have a de-solder pump, too, but it usually relaxes quietly in its holder if there's a connector to unplug. 😉
Are you saying there is no connector to un-mate?
Mine is from the early 1980's -- dunno if it's still available: Soldapullt (not a typo), Model DS 017. IIRC there's a newer model that has less kick-back.
Are you saying there is no connector to un-mate?
Mine is from the early 1980's -- dunno if it's still available: Soldapullt (not a typo), Model DS 017. IIRC there's a newer model that has less kick-back.
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I have a cheap China pump.
But it's working.
Pro'sKit SS-331H dispositif de dessoudage de ventouse a souder electrique pompe a dessouder a aspiration forte haute puissance antistatique pour la reparation de circuits imprimes Sale - Banggood Mobile
Pro'sKit SS-331 Desolder Station Review - YouTube
No connector, M301 M302 are soldered on main pcb
But it's working.
Pro'sKit SS-331H dispositif de dessoudage de ventouse a souder electrique pompe a dessouder a aspiration forte haute puissance antistatique pour la reparation de circuits imprimes Sale - Banggood Mobile
Pro'sKit SS-331 Desolder Station Review - YouTube
No connector, M301 M302 are soldered on main pcb
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PreamplificatorS disconnected. Ok? then,
Disconnect zener diot? replace R245. so?
If R245 burned. then disconnect Q156. replace R245. so?
If R245 burned then disconnect Q155.. So, what happened?
Disconnect zener diot? replace R245. so?
If R245 burned. then disconnect Q156. replace R245. so?
If R245 burned then disconnect Q155.. So, what happened?
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OK, now I see the 2nd picture bullitt mentioned. 😀
Sorry -- wouldn't have asked you to pull 'em if I'd known they were hard-wired modules.
So, now we're back to finding other stuff that's using that regulated +18V. Plug a 'mini-hook' into the ground socket of your DMM, hook it onto the Emitter of Q155 or Cathode of D119, and start working your way around the main board with the red probe, section by section, in search of things with less than 0,5 ohms or so continuity. That current in excess of ~123mA has to be going somewhere.
And don't put the preamp/lineamp modules back in yet ..
Cheers
edit: Or you could replace R245 with a higher value -- say 150 ohms -- and follow the low +18V around to see where it goes.
Sorry -- wouldn't have asked you to pull 'em if I'd known they were hard-wired modules.
So, now we're back to finding other stuff that's using that regulated +18V. Plug a 'mini-hook' into the ground socket of your DMM, hook it onto the Emitter of Q155 or Cathode of D119, and start working your way around the main board with the red probe, section by section, in search of things with less than 0,5 ohms or so continuity. That current in excess of ~123mA has to be going somewhere.
And don't put the preamp/lineamp modules back in yet ..
Cheers
edit: Or you could replace R245 with a higher value -- say 150 ohms -- and follow the low +18V around to see where it goes.
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