But?
CR-1020 relay won't engage
- Thread starter goldswimmerb
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Probably throwing this one on the back burner, traces seem to be checking out, reflowed solder joints to be sure that they were good too.
It's just strange that when I probe the base of T702 the relay closes immediately.
Meter load is enough to bias "on" the transistor.
I found the scan I had of the CR-2020, much higher resolution.
Okay so, there was an undocumented 470 ohm resistor in my unit, going from B to E on TR702, upon removing it the unit seems to work with the proper time delay, thoughts?
It would never work that way.. Did the resistor look OEM? I have a 2020 here. I'll check and see if its in the 2020. 2020 uses the same board.
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What do the voltages around TR702 read with it disconnected?
The CR-2020 I have here does not have the two holes in the PCB but.......... The 470Ω 1/4 watt OEM looking resistor was tacked on one end of R750 and the other end was not connected period. Frick'n weird...
The CR-2020 I have here does not have the two holes in the PCB but.......... The 470Ω 1/4 watt OEM looking resistor was tacked on one end of R750 and the other end was not connected period. Frick'n weird...
It still measures 470ohm, but with it removed my voltages are within +-.5v of the service manual
The last 2020 I did had the same resistor but it worked. Gotta love mid-production changes
I think with the beefier relay driver you will be OK without it.If the transistor is not running hot.
I have and idea it at one time it was tacked to a leg of TR702.
That's what I was thinking, since this driver is rated much much higher it should be fine. Was testing and it only gets slightly warm to the touch. Seems weird though...
Alright, so I'm back at it with this Yamaha, relay no longer clicking after I let it sit for a few days while I waited for parts to arrive. Not sure what's up, but my 25V +- rails are both showing 17.5v and my -13 is showing 10.8. not sure if the problems are related.