Yamaha A-1 Repair and restore: beyond Deoxit

[DaaDaa]

even though the whole episode is upsettng, i gotta say there is something about knowing what caused the problem i prefer it to not knowing, i was going crazy over nothing making sense. so while upsetting, knowing the reason brought a certain calm with it as well

 

[clinic-audio]

Rules :
1) forget all magic cables
2) if your relays click on both A1 and CA2010 then all power output transistors are good on BOTH units
3) follow the good advise to check all the fuses (amplifier not connected to anything and with power off , of course ! )

come back to us with report

 

[clinic-audio]

You said :

On the amp side: speaker conductors 1 and 3 are positive. conductors 2 and 4 are negative. on the speaker side conductors 1 and 2 are connected to positive and conductors 3 and 4 are connected to negative.
That's the problem , using this cable wired like this is complicate , you can't get correct connection this way !

Forget this cable (except if you made the correct connection of 1 and 3 together and 2 and 4 together AT THE BOTH END OF THE SAME CABLE )

 

[zaibatsu]

Did you check those fuses yet?
You may be in luck, I hope so

 

[DaaDaa]

Did you check those fuses yet?
You may be in luck, I hope so

I so appreciate all you guys' help. And yes finally some good news. I just opened the CA-2010 and immediately spotted a blown fuse in the power circuit board. it was a 1 amp 250V fuse so i used one from the A-1 and I used the corrected cable and viola music in both channels (seems like despite the short there was no damage to any components due to the fact that it was only operated in that condition for a few seconds). i used my newly acquired turntable and was able to listen to the david bowies changesbowie LP. i sighed with relief.

the reason that it took me so long is that an old undergrad physics buddy flew in from Alabama to visit so we had to entertain him so i didnt have much time and i wanted to only work on it with my 100% undivided focus.
with the CA-2010 in class A mode i hit 90db spl in the room when the volume knob is at the 11 o'clock position. that's how sensitive my speakers are and the powered subs help as well. so i spent a few minutes making sure my wife knows not to have the volume knob open all the way when, and if, she ever decides to use the amp. it will destroy the speakers. these omegas are unbelievably easy to drive. (funny thing is that she has no interest in using any of it. actually she asked me to buy her a blutooth speaker from bestbuy because my stereo makes her nervous hahaha. who can blame her as she witnessed me getting shocked quite a few times lol)

so now i will focus on undoing the damage that I have done to the A-1 i will also recap all of the power circuit (i have all caps except the 1000 micro farad which i forgot to buy).

 

[DaaDaa]

I also havew the upgrade kit for Ca-2010 which includes all caps required to recap (or so the seller claims) but honestly i think i will just let it sit. maybe after fixing the A-1 i will have the confidence but not now.

 

[DaaDaa]

 

[avionic]

. R121 and R122 measure 0.2 ohm, they should be 4.7 ohm.

I'm guessing this is and " in-circuit" measurement. Resistors never in my experience go down in value always up in value to infinite Ω's(open)... R121 and 122 need to be checked out of circuit.Or isolate it by unsoldering one lead .

 

[DaaDaa]

it is proving to be next to impossible for me to dewtermine and order every single component individually. i will havwe to reply on kits for les critical components. for electrolytic i ofcourse only order nichion and ehat is needed and match the stock component but maybe for less critical compoenets like ceramic caps i can use kits llike this:

https://www.ebay.com/itm/1200pcs-24-Values-50V-10pF-10uF-Monolithic-Ceramic-Capacitor-Assorted-Set-Box/112911716771?rt=nc&_trkparms=aid=555018&algo=PL.SIM&ao=2&asc=52935&meid=71175d5600324db086aff5e5e0b8e2d7&pid=100005&rk=4&rkt=12&sd=202322900222&itm=112911716771&_trksid=p2047675.c100005.m1851

not just because of funds but for time contraints. i will have to use these and hope that all the sizes that i need will be in this or this one:

https://www.ebay.com/itm/525Pcs-15V...capacitors&_from=R40&rt=nc&_trksid=m570.l1313

 

[DaaDaa]

I'm guessing this is and " in-circuit" measurement. Resistors never in my experience go down in value always up in value to infinite Ω's(open)... R121 and 122 need to be checked out of circuit.Or isolate it by unsoldering one lead .

yes it was but now it is outside and it definitely is way out of spec. i need to buy a tool for capacitor measurement tho.

 

[avionic]

yes it was but now it is outside and it definitely is way out of spec

How far out of tolerance ?

 

[DaaDaa]

one measure OL, the other measures 1.1 Mega ohm.
R119 and 120 are supposed to be 10 oh, they meaure 1.2 Mega ohm and 7 ohm. so one is actually measuring less than it should. all of this with my 15 dollar walmart multimeter.
i could take a picture, but it would just show a resistor in allkigator cables measring 7 ohms in a multi meter that is auto range so i dont set the range myself. I saw these 4 resistors all smoking for a good while before I took them out so i knew for a fact they would measure out of spec.

 

[avionic]

it is proving to be next to impossible for me to dewtermine and order every single component individually. i will havwe to reply on kits for les critical components. for electrolytic i ofcourse only order nichion and ehat is needed and match the stock component but maybe for less critical compoenets like ceramic caps i can use kits llike this:

https://www.ebay.com/itm/1200pcs-24-Values-50V-10pF-10uF-Monolithic-Ceramic-Capacitor-Assorted-Set-Box/112911716771?rt=nc&_trkparms=aid=555018&algo=PL.SIM&ao=2&asc=52935&meid=71175d5600324db086aff5e5e0b8e2d7&pid=100005&rk=4&rkt=12&sd=202322900222&itm=112911716771&_trksid=p2047675.c100005.m1851

not just because of funds but for time contraints. i will have to use these and hope that all the sizes that i need will be in this or this one:

https://www.ebay.com/itm/525Pcs-15Values-DIP-Monolithic-Multilayer-Ceramic-Chip-Capacitors-Assortment-Kit/202322900222?epid=6019897099&hash=item2f1b6274fe:g:F7EAAOSwqDhbCUFw&_sacat=0&_nkw=ceramic+capacitors&_from=R40&rt=nc&_trksid=m570.l1313

Your wasting your money on those kits. 90% of it you will probably never use.

 

[avionic]

one measure OL, the other measures 1.1 Mega ohm.
R119 and 120 are supposed to be 10 oh, they meaure 1.2 Mega ohm and 7 ohm. so one is actually measuring less than it should. all of this with my 15 dollar walmart multimeter.
i could take a picture, but it would just show a resistor in allkigator cables measring 7 ohms in a multi meter that is auto range so i dont set the range myself. I saw these 4 resistors all smoking for a good while before I took them out so i knew for a fact they would measure out of spec.

What resistance does your meter read if you short the two test leads together ?

 

[DaaDaa]

Your wasting your money on those kits. 90% of it you will probably never use.

for sure. but it is still cheaper than choosing 3 sizes and ordering 5 of each from mouse and paying 7.99 for shipping, the time that it saves is 10 times more important tho. i just dont have the time to look them up one by one. this is 24 values pieces for less money than to order just 3 values 10 of each from mouser. and then im might need other valuies down the road when i move on to the 2010

 

[DaaDaa]

What resistance does your meter read if you short the two test leads together ?

depends a little on the cable. with alligators that i have it measurement 0.9 ohms.

 

[avionic]

Most likely the smoked 10Ω measured the same as the 7Ω before it burnt up.

 

[DaaDaa]

yes it was but now it is outside and it definitely is way out of spec. i need to buy a tool for capacitor measurement tho.

is this recommended? i think i have seen poeple buying recommending something like this:
https://www.ebay.com/itm/12864-Mega...m=R40&rt=nc&_trksid=m570.l1313&LH_TitleDesc=0

 

[zaibatsu]

Yes those Mega328 testers work well.

I'd skip the large combo kits, like avionic said you won't use most of it, and the other thing is the parts may be of questionable quality. I think it's worth taking your time and making a list of all parts you need, then just doing one large mouser order (and getting free shipping) instead of many small ones. With mouser / digikey you're guaranteed genuine parts, worth paying a little extra for in my book.

FYI it's fairly unlikely for ceramic and film caps to blow anyway. Usually most failures will involve a combo of semiconductors (transistors, diodes, etc) and resistors. If you do the thing I suggested where you mark in red the failed parts on the schematic, we can help suggest some surrounding parts to test (so you don't have to test / replace more things than you need to).

It's probably good to wait for the Mega328 to arrive, and also I wouldn't recap it until you get the problem fixed - but if you do - just be careful to note polarity of what comes out (use a marker to mark negative on the board before removing the old caps, perhaps).

 

[DaaDaa]

Yes those Mega328 testers work well.

I'd skip the large combo kits, like avionic said you won't use most of it, and the other thing is the parts may be of questionable quality. I think it's worth taking your time and making a list of all parts you need, then just doing one large mouser order (and getting free shipping) instead of many small ones. With mouser / digikey you're guaranteed genuine parts, worth paying a little extra for in my book.

FYI it's fairly unlikely for ceramic and film caps to blow anyway. Usually most failures will involve a combo of semiconductors (transistors, diodes, etc) and resistors. If you do the thing I suggested where you mark in red the failed parts on the schematic, we can help suggest some surrounding parts to test (so you don't have to test / replace more things than you need to).

It's probably good to wait for the Mega328 to arrive, and also I wouldn't recap it until you get the problem fixed - but if you do - just be careful to note polarity of what comes out (use a marker to mark negative on the board before removing the old caps, perhaps).

ordered the mega328. thanks for the advice. it is going to be very useful to me.

the point is taken about kits and it was also taken before too but using the service manual and the amp itself it took me 45 minutes to identify and add to cart 11 components and then i have to decide how many to buy for this use and foreseeable future use. just cant keep doing this. like i said im a student and, as it is i am sleep deprived. so what i did is that, last night i ordered a kit of 1500 half watt 5% carbon resistors in 35 values and ceramic resistors in 15 values and mylar resistors in 15 values. then for the more critical transistors, diodes and caps I stick with mouser and the usual audiophile approved components like nichicon. the reason that i even considered the ceramic caps is that Mr. Yamaha in his CA-2010 thread had replaced some of them on the phono/preamp board so i m basically trying to retrace his steps and go through mine. although i am not sure that i can go as deep as he did. disassbling all those knobs abd switches and cleaning inside sounds incredibly daunting. maybe after the unit is completely fixed but not now.

as for the recapping. yes definitely i will wait until i find the underlying problem as you guys said.
in the case of 2010 with the crackling and the channel being intermittent, i already suspect and hope that it is the power supply board caps and no other problems. so I suspect that fixing the problem and recapping will overlap on that particular board but still i wont start just taking caps out until I have a better understanding of the situation.