LFazio51
Active Member
Good afternoon all and Happy Holidays! Hard to believe 2017 is almost over (sorry for the overused cliche')!
I recently acquired a CR1020 with the intent of restoration. I'm short on experience (other than over a year of research prior to engaging) but am diligent towards educating myself in order to gain the necessary comfort level to proceed with the actual work. Upon power-up (w/DBT) the unit is very distorted on one channel while the speaker protect relay "buzzes" in place. Given the age and desire to restore it, I shut it down and began inspecting and learning my way around it.
Upon inspection , it became clear that the design of the e.cap board, coupled with the power supply board that houses the speaker protect relay, leaves much to be desired; likely the reason behind the service bulletin calling to replace resistive components due to heating. The left side of the power supply board on my 1020 is situated directly over the left (relative to board placement) diode rectifier on the e.cap board and is severely discolored due to this heat. I'm almost certain that the additional heat generated by this design has also shortened the life of many capacitors on the left side of the main power supply board. Implementing the SB and replacing faulty capacitors seems to be in order for proper restoration. I'm looking for additional research in this task and was hoping to capitalize on some veteran knowledge in order to properly prepare myself prior to initiating repairs - any advice and direction would be greatly appreciated.
I've also noticed that there are quite a large quantity of capacitors and small transistors on the main power supply board as well. The (2) transistors in the middle of the board, attached to heat sinks (I believe TR712/715 - SD284/SD880) look to be very lose. I'll test once I secure a tester but I'm a little hesitant to replace ALL caps since there are so many. Again, I would certainly welcome any direction in this area as well.
Working on the main power supply board would seem to require complete disconnection if your goal was to gain easy access for soldering such small components as well as properly cleaning it, and, gaining easy access the e.cap board below. As previously stated, I'm absorbing ALL advice and recommendations.
I've not ventured into the main power amp boards as my initial thoughts were to gain easier access once removing the power supply board and e.cap board if recommend by others. I'm sure there is a wealth of knowledge concerning this component of the unit and any advice would be most gracious.
I'm not going to concern myself with the pre-amp/tone, phono, or tuner board until restoration of the power supply board is complete; I'd like to know clean supply is available before troubleshooting or simply upgrading capacitors and transistors on this board. I believe this to be the proper approach but sometimes, due to the level of disassembly, I also realize that it may make sense practically due to access. Overall direction on "repair logic" with respect to sequence would go a long way to point me in the right direction.
I plan to source the 12v 60ma lamps (incandescent) from David Wojnarowski and have learned that these are wired in "series" but they don't look like it. In fact, they appear to be soldered to pins "LB, LC, & E for the dial pointer where it seems like they should be wire-wrapped. They are also not the typical "red/white" leads, rather solid white for both terminals. If considering connectors LB & LC situated along the bottom left side on the power supply board (while viewing the unit from the front), the (2) bulbs connected appear to have a leg going to each of these terminals - that looks to me like they're in parallel and, along with the solder, causes me to believe someone else may have incorrectly attempted to replace them (photo below). Any advice or diagrams to confirm how these lamps should connect would be very helpful.
On to parts procurement. I know that capacitors can be sourced from Mouser or Digikey, however, cross-referencing and sourcing components such as the proper transistors, speaker protect relay, etc. is not something I'm too familiar with. If anyone can help in this area it would save me a great deal of time, but more importantly, give me a fighting chance at restoration, rather than blowing-up my unit as a result of using an incorrect transistor (i.e. TR712/715), etc.
Finally, the CR1020 manual from HFE and AK appear to be severely lacking in clarity, if anyone has a reasonably better copy, or can direct me to one, many thanks!
Thanks for indulging me on such a lengthy post but I was hoping to properly convey my status so those able to help would take an interest and do so. I've posted some pics that may help with anyone that has some additional questions concerning yearly design; seems to me that Yamaha may have modified the e.cap and power supply board config in later years - I believe mine would be an earlier model. Again, I think most can see my status with regards to this project and where I need to go, so, thanks for reading and much appreciation in advance for all your advice and support.
Happy Holidays and Merry Christmas!
I recently acquired a CR1020 with the intent of restoration. I'm short on experience (other than over a year of research prior to engaging) but am diligent towards educating myself in order to gain the necessary comfort level to proceed with the actual work. Upon power-up (w/DBT) the unit is very distorted on one channel while the speaker protect relay "buzzes" in place. Given the age and desire to restore it, I shut it down and began inspecting and learning my way around it.
Upon inspection , it became clear that the design of the e.cap board, coupled with the power supply board that houses the speaker protect relay, leaves much to be desired; likely the reason behind the service bulletin calling to replace resistive components due to heating. The left side of the power supply board on my 1020 is situated directly over the left (relative to board placement) diode rectifier on the e.cap board and is severely discolored due to this heat. I'm almost certain that the additional heat generated by this design has also shortened the life of many capacitors on the left side of the main power supply board. Implementing the SB and replacing faulty capacitors seems to be in order for proper restoration. I'm looking for additional research in this task and was hoping to capitalize on some veteran knowledge in order to properly prepare myself prior to initiating repairs - any advice and direction would be greatly appreciated.
I've also noticed that there are quite a large quantity of capacitors and small transistors on the main power supply board as well. The (2) transistors in the middle of the board, attached to heat sinks (I believe TR712/715 - SD284/SD880) look to be very lose. I'll test once I secure a tester but I'm a little hesitant to replace ALL caps since there are so many. Again, I would certainly welcome any direction in this area as well.
Working on the main power supply board would seem to require complete disconnection if your goal was to gain easy access for soldering such small components as well as properly cleaning it, and, gaining easy access the e.cap board below. As previously stated, I'm absorbing ALL advice and recommendations.
I've not ventured into the main power amp boards as my initial thoughts were to gain easier access once removing the power supply board and e.cap board if recommend by others. I'm sure there is a wealth of knowledge concerning this component of the unit and any advice would be most gracious.
I'm not going to concern myself with the pre-amp/tone, phono, or tuner board until restoration of the power supply board is complete; I'd like to know clean supply is available before troubleshooting or simply upgrading capacitors and transistors on this board. I believe this to be the proper approach but sometimes, due to the level of disassembly, I also realize that it may make sense practically due to access. Overall direction on "repair logic" with respect to sequence would go a long way to point me in the right direction.
I plan to source the 12v 60ma lamps (incandescent) from David Wojnarowski and have learned that these are wired in "series" but they don't look like it. In fact, they appear to be soldered to pins "LB, LC, & E for the dial pointer where it seems like they should be wire-wrapped. They are also not the typical "red/white" leads, rather solid white for both terminals. If considering connectors LB & LC situated along the bottom left side on the power supply board (while viewing the unit from the front), the (2) bulbs connected appear to have a leg going to each of these terminals - that looks to me like they're in parallel and, along with the solder, causes me to believe someone else may have incorrectly attempted to replace them (photo below). Any advice or diagrams to confirm how these lamps should connect would be very helpful.
On to parts procurement. I know that capacitors can be sourced from Mouser or Digikey, however, cross-referencing and sourcing components such as the proper transistors, speaker protect relay, etc. is not something I'm too familiar with. If anyone can help in this area it would save me a great deal of time, but more importantly, give me a fighting chance at restoration, rather than blowing-up my unit as a result of using an incorrect transistor (i.e. TR712/715), etc.
Finally, the CR1020 manual from HFE and AK appear to be severely lacking in clarity, if anyone has a reasonably better copy, or can direct me to one, many thanks!
Thanks for indulging me on such a lengthy post but I was hoping to properly convey my status so those able to help would take an interest and do so. I've posted some pics that may help with anyone that has some additional questions concerning yearly design; seems to me that Yamaha may have modified the e.cap and power supply board config in later years - I believe mine would be an earlier model. Again, I think most can see my status with regards to this project and where I need to go, so, thanks for reading and much appreciation in advance for all your advice and support.
Happy Holidays and Merry Christmas!