Ca-1010 Transistor Replacements

[jeromach]

I would not be surprised when a VD1212 caused all the trouble in the first place.

Good you found it!

PS: But do replace all 1212's!

 

[Blue Shadow]

@Bluhn321 did you post a follow up on this? I'm hanging here waiting for your parts to come in!!

 

[Bluhn321]

Oh, I totally forgot!

After replacing all the 1212's and TR215 with a KSC1845 the lost channel came back! I also replaced all but the filter caps a little while later.

Still use it as my daily driver and love it!

 

[Blue Shadow]

Excellent.

 

[clinic-audio]

Oh, I totally forgot!

After replacing all the 1212's and TR215 with a KSC1845 the lost channel came back! I also replaced all but the filter caps a little while later.

Still use it as my daily driver and love it!

just re-mount the 2 VD1212 at their place and you will understand immediately how stupid it is to replace them when it is not necessary !! I see all the time "replace VD1212 " what for ?
Can the advised member what is the technical reason to do so !
VD1212 is a varistor
2 IN4148 are simply diodes , will you understand that ?
Why the manufacturer use VD1212 if 2 1N418 will do the job fine ?? Tell me
I do service on critical and very expensive units with VD1212 since 42 years . Do you think I am really stupid to not replace them if it is necessary ?
I never get many units where it was necessary to do so
why don't you replace everything in your YAMAHA , this way your problem will be gone but you will not learn anything by replacing components without understanding how the circuits works and what you are doing
There is some good members here giving good advises , follow them and don't "copy" what some other (non experienced) does

 

[rottalpha]

Keep ESD in mind when handling JFET's.

I do not find them that sensitive...nothing like mosfets

 

[avionic]

I do not find them that sensitive...nothing like mosfets

Old school training. Field effect transistors are more susceptible to ESD damage than BJT.

 

[avionic]

nothing like mosfets

Actually CMOS is the real sensitive devices.

 

[rottalpha]

Actually CMOS is the real sensitive devices.

Roger that

 

[rottalpha]

Found TR215 faulty which is a 2SC1775 and the VD1212 next to it open.

replace them if it is necessary

He did say he found one open

 

[Vint Age]

just re-mount the 2 VD1212 at their place and you will understand immediately how stupid it is to replace them when it is not necessary !! I see all the time "replace VD1212 " what for ?

Clinic, people always confuse VD1212 for the infamous VD2121 varistors found in the Sony V-FET amps. Like you I have yet to find a failed VD1212 and I would prefer them to 1N4148's.

 

[clinic-audio]

people always confuse VD1212 for the infamous VD2121 varistors found in the Sony V-FET amps.
That do not surprised me

 

[clinic-audio]

Like you I have yet to find a failed VD1212 and I would prefer them to 1N4148's. Yes !
if you wish to replace VD1212 please use IF000790 (MV12) this is a perfect sub

 

[avionic]

if you wish to replace VD1212 please use IF000790 (MV12) this is a perfect sub

And where does one purchase these little gems ? Clinique Audio in Bosquentin?

 

[zaibatsu]

Old school training. Field effect transistors are more susceptible to ESD damage than BJT.

I read in a recent article that ESD damage commonly affects component lifespan, but the impact of the damage may not show for years. Premature failure is the end result, but it's hard to predict the magnitude of damage from handling transistors at hobby level.

I say the old school training still applies, better safe than sorry.

 

[avionic]

I read in a recent article that ESD damage commonly affects component lifespan, but the impact of the damage may not show for years. Premature failure is the end result, but it's hard to predict the magnitude of damage from handling transistors at hobby level.

I say the old school training still applies, better safe than sorry.

Thats my understanding as well. Eagle avionics was loaded with CMOS....

 

[clinic-audio]

And where does one purchase these little gems ? Clinique Audio in Bosquentin?

Hello Dave
yes , why not but asking this part from an official YAMAHA service station in USA will be more easy ! That's the reason why I give the Yamaha part number in my message

 

[rottalpha]

Clinic, people always confuse VD1212 for the infamous VD2121 varistors found in the Sony V-FET amps. Like you I have yet to find a failed VD1212 and I would prefer them to 1N4148's.

I think he said 1212 not 2121

and the VD1212 next to it open

 

[clinic-audio]

Hello Rottalpha

yes he (like many) make confusion

 

[eizner23]

Gee whiz, even echowars recommends two 4148 as sub for 1212

http://audiokarma.org/forums/index.php?threads/vd1212-varistor-diode.101598/