2 options really,
Return for full refund and travel expenses.
Request hefty discount to compensate for its reduced value.
If you go route 2 then you need to assess if the PA board it functional. Then apply the Dutch service manual updated and suicide diodes replacements. Re cap as needed/desired and replace the vFets ( I believe you have been offered matched replacements, but them in any case for spares if you find another amp).
I have a stock 4650 PA board but the vfet sockets and thermistor are missing. Would be willing to sell at reasonable price if needed.
Good luck with the seller, I think you have him cornered and you are in the right.
Jon
Return for full refund and travel expenses.
Request hefty discount to compensate for its reduced value.
If you go route 2 then you need to assess if the PA board it functional. Then apply the Dutch service manual updated and suicide diodes replacements. Re cap as needed/desired and replace the vFets ( I believe you have been offered matched replacements, but them in any case for spares if you find another amp).
I have a stock 4650 PA board but the vfet sockets and thermistor are missing. Would be willing to sell at reasonable price if needed.
Good luck with the seller, I think you have him cornered and you are in the right.
Jon
In defence of the retail store it’s possible that they sold it on without even knowing what had been ~butchered~ modified internally
To most uneducated laypersons it’s just a vintage amp
To most uneducated laypersons it’s just a vintage amp
He’s now gone cold on me he won’t even respond to my emails. I’m not sure if I will still take it a massive discount I’m thinking $100 maybe so. I’d rather get my money back or possibly get the small claims court judge to agree that whatever it cost to repair third-party he pays for it.
No I do believe he knows it was altered and modified I think he was hoping to just unload it to an unsuspecting person even pre-sales he said it was OK and are all original I have it in writing from him.
For him to say that my warranty is voided for me opening the hood of my vintage hot rod with matching serial numbers to check the number by opening the hood will voiding the warranty and me finding out that they’re not matching numbers it’s just ludicrous. I’m the fool for not forcing him to show me before I paid and I should’ve never said a thing about them being fake chips and let him just try to fix it which he cannot.
No I do believe he knows it was altered and modified I think he was hoping to just unload it to an unsuspecting person even pre-sales he said it was OK and are all original I have it in writing from him.
For him to say that my warranty is voided for me opening the hood of my vintage hot rod with matching serial numbers to check the number by opening the hood will voiding the warranty and me finding out that they’re not matching numbers it’s just ludicrous. I’m the fool for not forcing him to show me before I paid and I should’ve never said a thing about them being fake chips and let him just try to fix it which he cannot.
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Good luck. Odds are he won't even show up and there will be a default judgement,
which he won't pay.
which he won't pay.
Hi everyone! I'm new to this forum in search for some information about a Sony TA-4650. I have just gotten this amp after my late uncle, and all information i find on the internet tells me to upgrade it. The amp works pretty good but needs a little cleaning of the pots since it have been unused since 1988/89. Is there anybody who can help me with the service bulletins needed? I guess it's number 41, 49, 51 and 62. As i understand, the most critical upgrade would be the diodes to save the VFET's. What's the recommended diodes to upgrade with?
Regards,
Tor Arild
Regards,
Tor Arild
D302, D352, D414. These are the suicide diodes - to be replaced with two 1N4148 (or equivalents) in series.
Don't turn the amp on until this has been fixed first!
In the supply there is a fix regarding D403.
There are several threads about the 4650 (& 5650) in the solid state section here. Do a search and have a good read.
The service bulletins are posted also (translations included).
The Sony_TA-4650_CircuitOperation.pdf is another good read, and only posted once.
Just as an extra backup.
Thanks a lot! I see in some other threads that a 1N4158 diode is mentioned. Is there any critical difference between 1N4148 and 1N4158? (I'm a car mechanic, not a very good audio repairer..)
1N4158 is a typo - 1N4148 is the right part. The 4158 is a 6.8 zenerdiode by Motorola.
Which threads? Here on DIYaudio? (@ admins: no intentions to corpse digging!)
These are (the most) informing threads:
Andrew 1
Andrew 2
Andrew 3
VFET747
neighbors
and various tube channels.
I'm a electronic engineer, not a very good mechanical engineer: after puttings things together, there are still nuts, bolts, screws, washers, locking rings, metal chips and what not on the table which were not present at start. Be careful!
Thanks a lot Citizen! I will be carefull 🙂
"Hi citizen, yes all the 3 death diodes on have been replaced with twin 1N4158 didoes also the D403 on power supply board replaced with double didoes and the center of these two diodes soldered to the common ground of the power supply."
This is from a thread i read yesterday that made me unsecure since i've already ordered 1N4148 diodes..
Regards,
tortrygg
"Hi citizen, yes all the 3 death diodes on have been replaced with twin 1N4158 didoes also the D403 on power supply board replaced with double didoes and the center of these two diodes soldered to the common ground of the power supply."
This is from a thread i read yesterday that made me unsecure since i've already ordered 1N4148 diodes..
Regards,
tortrygg
Assuming this message was addressed to me, I didn't noticed that typo then.
It is the 1N4148 proper.
For the D403 modification, you'll need two 1N4002 diodes (1N4002 -- 1N4007 range, not the 1N4001!).
Cheerio.
It is the 1N4148 proper.
For the D403 modification, you'll need two 1N4002 diodes (1N4002 -- 1N4007 range, not the 1N4001!).
Cheerio.