That's great news Jan, well done. I get the feeling that this PSU is extremely fussy on actual devices used.
The bulbs question cropped up earlier although we never found out what they were (from memory).
http://www.diyaudio.com/forums/solid-state/181121-sony-ta-f6b-psu-repair-28.html#post3590492
Might be worth doing a bit of maths (you need the relay resistance and voltage) and drawing it all out putting the voltages in and then work out what "resistance" the bulbs have to be, and what resistance to generate the required relay voltage etc and take it from there.
The bulbs question cropped up earlier although we never found out what they were (from memory).
http://www.diyaudio.com/forums/solid-state/181121-sony-ta-f6b-psu-repair-28.html#post3590492
Might be worth doing a bit of maths (you need the relay resistance and voltage) and drawing it all out putting the voltages in and then work out what "resistance" the bulbs have to be, and what resistance to generate the required relay voltage etc and take it from there.
I came to the same conclusion, noone really know the specs on those bulbs and Sony keep it a big big secret in the manual.
Google is no friend on this subject, some sites say 250mA others 70mA, most agree on the 6.3V.
The relay is marked 24VDC.
The unoriginal bulbs draws about 200mA@6.3V but as they are unmarked I don't even know if 6.3V is right, but they do light up about the right amount@ 6.3V.
Mounted in the amp they barely glow, and R804 (150Ohm/7W) gets pretty hot.
When I take one bulb out, then the remaning one lights up, R804 still gets warm, but not nearly as much.
Anyway I'll measure the relay resistance and the voltage over the relay and bulb, maybe that will shine some light(!) over the bulbs
Maybe 6.3V/70mA isn't far off.
Google is no friend on this subject, some sites say 250mA others 70mA, most agree on the 6.3V.
The relay is marked 24VDC.
The unoriginal bulbs draws about 200mA@6.3V but as they are unmarked I don't even know if 6.3V is right, but they do light up about the right amount@ 6.3V.
Mounted in the amp they barely glow, and R804 (150Ohm/7W) gets pretty hot.
When I take one bulb out, then the remaning one lights up, R804 still gets warm, but not nearly as much.
Anyway I'll measure the relay resistance and the voltage over the relay and bulb, maybe that will shine some light(!) over the bulbs
Maybe 6.3V/70mA isn't far off.
Lets put some numbers in and say the relay is 600 ohm (wild guess). You have 50 volts across a chain of 150 + 82 + 100 ohm together with the 600 ohm across the 100 + 82. Which all simplifies to 150 ohm in series with 139 ohm. Shove 50 volts across that and you have 0.17 amps available if the bulbs were a short. Lets say each bulb was 6.3 volt at 70ma. That's a hot resistance of 90 ohms per bulb. Two in parallel, 45 ohms.
So if we stick those in the chain we get 150 + 139 + 45. Current available, 0.15 amps. Voltage across relay is 0.15 times 139 which is 21 volts. Sounds reasonable. Voltage across bulbs, 0.15 times 45 ohms which is 6.75 volts. Bit high but in the right ball park and the relay is an unknown. So 6.3 volts 70 ?ma could be about right
Measure the relay. Do you have a Sony part number for the bulbs ?
So if we stick those in the chain we get 150 + 139 + 45. Current available, 0.15 amps. Voltage across relay is 0.15 times 139 which is 21 volts. Sounds reasonable. Voltage across bulbs, 0.15 times 45 ohms which is 6.75 volts. Bit high but in the right ball park and the relay is an unknown. So 6.3 volts 70 ?ma could be about right
Measure the relay. Do you have a Sony part number for the bulbs ?
I have a similar problem I get 228V accross C809 is this enough?
The voltage across C809 equals your mains voltage. Netherlands ? 230vac.
The voltage across C809 equals your mains voltage. Netherlands ? 230vac.
Thanks for the reply, Netherlands has 220V so 228V is a bit high but should be no problem.
My amp worked but I got different en inconsistant volumes on both channels so
I replaced all the caps in the preamp and tone controlls. After that it worked perfectly!
This year I decided to change all caps on the main amp and when I was done and reconnected it to the main the relais would not click and I get a hight pitched beep....
In order to solve the problem I replaced the caps in de PSU but still no successs and I now have to find out what's causing the problem.
I read almost all of this discussion but since I'm not a technician like some guidelines where to start measuring en testing.
If your not familiar with these type of power supplies then I'm afraid its going to be an uphill struggle. I think we covered most things power supply related in the course of this thread. From what you say, it sounds like you replaced the caps on a working amp and after that the problem appeared... if so then you need to check all your work and the values of parts fitted etc.
Were the caps you fitted in the audio section or the power supply ? The high pitched noise could be the power supply working into a short circuit or trying to supply to much current.
Were the caps you fitted in the audio section or the power supply ? The high pitched noise could be the power supply working into a short circuit or trying to supply to much current.
If your not familiar with these type of power supplies then I'm afraid its going to be an uphill struggle. I think we covered most things power supply related in the course of this thread. From what you say, it sounds like you replaced the caps on a working amp and after that the problem appeared... if so then you need to check all your work and the values of parts fitted etc.
Were the caps you fitted in the audio section or the power supply ? The high pitched noise could be the power supply working into a short circuit or trying to supply to much current.
With time and effort I will succeed in repairing this amp (if nessessary I will put all the old parts back and take it one step at a time
The high pitched sound does not seem to come from the PSU. I disconnected the PSU output and the sound disappeared.
I will check all the replaced parts and read the remaining of this thread.
(I didn't replace the two 0.0015mF 400V caps in the PSU though)
Measure the relay. Do you have a Sony part number for the bulbs ?
Sorry for the late reply, life got in the way.
The relay measure 1622 Ohm (it's marked 24VDC).
The Sony part number for the bulbs is 1-518-273-00
Google isn't my friend, the few places who sell them, are out of stock.
It was a long while back.
Bulbs... its either a case of finding something similar to the originals... or modifying slightly the component values to make something close to the originals work... or even looking at fitting LED's as a possible mod although that always brings issues of getting constant and even illumination.
What about small panel bulbs for cars or bikes ?
Bulbs... its either a case of finding something similar to the originals... or modifying slightly the component values to make something close to the originals work... or even looking at fitting LED's as a possible mod although that always brings issues of getting constant and even illumination.
What about small panel bulbs for cars or bikes ?
Maybe those will fit Sony Lampen / lamps TA-2000 F ... CAS | eBay
But according to the TA-2000F manual they are rated at 8V/0.3A, so modifying the resistors will be needed.
But according to the TA-2000F manual they are rated at 8V/0.3A, so modifying the resistors will be needed.
Yes, I guess they wont work, unless I take the 8V somewhere else, but then I need to find 24V for the relay too...
Looking at http://www.diyaudio.com/forums/solid-state/181121-sony-ta-f6b-psu-repair-63.html#post3763761 using 1622 Ohm, instead of 600 Ohm, it looks like 6.3V 70mA is spot on (if I understand Ohm's law right).
6.3V/70mA is impossible to find, even in other shapes and sizes.
Maybe LED is the only way to go, two yellow and one white might give the same yellowish glow as the original bulbs...
Looking at http://www.diyaudio.com/forums/solid-state/181121-sony-ta-f6b-psu-repair-63.html#post3763761 using 1622 Ohm, instead of 600 Ohm, it looks like 6.3V 70mA is spot on (if I understand Ohm's law right).
6.3V/70mA is impossible to find, even in other shapes and sizes.
Maybe LED is the only way to go, two yellow and one white might give the same yellowish glow as the original bulbs...
Getting the relay to work should be straightforward although the original circuit uses the "cold resistance" of the bulbs, which is very low, to give the relay an initial kick. The voltage on the relay coil will then fall to a holding value (which saves power and heat dissipation).
Arrange the resistors to give around 20 to 24 volts on the relay and it should all work.
LED's are great but I find you need a thick opaque diffuser (plastic) in front of them to spread the light.
Arrange the resistors to give around 20 to 24 volts on the relay and it should all work.
LED's are great but I find you need a thick opaque diffuser (plastic) in front of them to spread the light.
14 seconds is too long... 100uf and 35k (ish... its complicated by the fact the cap is fed from a divider) should give a delay of around 4 seconds but that delay can be overridden by Q404/405 and Q402/403
The voltage on C404 rises exponentially as it charges and the two relay driver transistor base/emitter junctions "clamp" the cap voltage at around 1.4 volts.
Change the cap first
Just a little update, now that I've recapped the whole amp, the relay clicks after only 4 seconds, just as you predicted.
Were the caps you fitted in the audio section or the power supply ? The high pitched noise could be the power supply working into a short circuit or trying to supply to much current.
It's been a while but today I took my amp from the shelve to check all components. All caps in the power amp match the schematics, the same with the caps in the power supply (I changed only the electrolytic caps).
I wanted to measure voltages to see what the voltages in the PSU where so I disconnected the output from the PSU tot the amp and added a jumper from the heatsink to the frame. When I switched on the amp I got the same high pitch sound coming from the PSU board. I want to connect everything and see what will happen but I have to make a short with bulb to discharge the PSU first. I'm open for suggestions as how to approach this problem.
It's been a while
Lol, almost a year
If the PSU is making a high pitched noise then it may be locked and running at a harmonic or just running at the wrong frequency. Very difficult to suggest much really... I think the first thing would be to look at the secondary outputs on a scope and try and gauge what is happening by looking at the frequency and what the overall waveshape looks like.
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