2270
- Thread starter HBrown
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HBrown
Active Member
Well, turns out the pot the guy dug up for me has got issues. Looking through the slots in the side of it with a strong light and magnification I can see that the little wipers for the rearmost of the two ganged pots is screwed up. There are supposed to be three fingers- only one is left in place. Another is bent out of place and the third is gone. The pot functions on a resistance test, but if I'm gonna fix this receiver I want the volume pot to be 100%. Back to looking. May look into the bartertown thing.
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No free lunch with this old stuff.
You did not reply what schematic represents the model that you have, so without knowing this, I can not guide you as what what to hook up where.
On the pot you showed, the tap for loudness comp is on the top. As any normal pot, looking at it from the front, the left lug is to go to ground(CCW), so trace that wire back to the ground.
center(wiper) goes to the output, and the right is the signal in from the previous stage(pre-amp).
All this can be measured with your ohmmeter.
You did not reply what schematic represents the model that you have, so without knowing this, I can not guide you as what what to hook up where.
On the pot you showed, the tap for loudness comp is on the top. As any normal pot, looking at it from the front, the left lug is to go to ground(CCW), so trace that wire back to the ground.
center(wiper) goes to the output, and the right is the signal in from the previous stage(pre-amp).
All this can be measured with your ohmmeter.
HBrown
Active Member
Thanks Rick- that helps- I have yet to get the manuals/schematics printed out so I can study them properly- I was about to go blind trying to look at them on a smartphone. I was planning on getting that pot I have installed in there and then move on to the missing transistor issue- until I found the issue with the pot. I didn't have much invested in the pot so no big deal. I'm still trying to shift gears and get my head wrapped around this receiver. It's a different animal from that pioneer. Seems to me the last guy in there got this one to a point that the face would light up so they could sell it- then ran for the hills.
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Sorry I have no use for a smart phone for the very fact that the screen size is useless for what I do. Wait til you get old and far sighted, then you will be constantly looking for your cheater glasses. So you must not be 40+ yet 
You do not need to print out the sch just to identify what unit type that you have.
Just jot down what the PCB's have printed on them (P600 etc) for assembly numbers and then look at the two schematics, that we have and compare.
Now that you show me the pot, the Alpha one from Mouser would be a perfect fit except no tap for loudness compensation. You are lucky it is not a pcb mounted pot as it makes finding a sub and assembly much easier.
Good luck
Rick
You do not need to print out the sch just to identify what unit type that you have.
Just jot down what the PCB's have printed on them (P600 etc) for assembly numbers and then look at the two schematics, that we have and compare.
Yes and No, it is the way it is documented, the way they draw the schematics. I agree that the Pioneer documentation is better than the others. Hard to trace wires/nets when they are bunched together and transverse more than one page. I agree printing out helps out in this regard.
Now that you show me the pot, the Alpha one from Mouser would be a perfect fit except no tap for loudness compensation. You are lucky it is not a pcb mounted pot as it makes finding a sub and assembly much easier.
Good luck
Rick
It's more of a matter of before I forget!
Here's some pics I did grab at lunch.
Looking from the front. Straight down.
Rotated to about "10:30". You can see the loudness taps although they are a bit out of focus. Red to the rear and white in front. Those wires come from the loudness pushbutton switch.
Back around to about "2:00".
Now from the back, the volume pot is now on the right.
Still from the back but swung around to the left a bit.
Hope that gets it for you when you do snag a pot. If you have questions, give me a holler via PM and I'll try to help clear things up.
Here's some pics I did grab at lunch.
Looking from the front. Straight down.
Rotated to about "10:30". You can see the loudness taps although they are a bit out of focus. Red to the rear and white in front. Those wires come from the loudness pushbutton switch.
Back around to about "2:00".
Now from the back, the volume pot is now on the right.
Still from the back but swung around to the left a bit.
Hope that gets it for you when you do snag a pot. If you have questions, give me a holler via PM and I'll try to help clear things up.
A fine mess of wires
Nice pics, can even spot the dirt.:scratch2:
You can see the braid that they used from the shielded cable to make the ground connections.
Looks straight forward
Good Luck Mr. Brown
Rick
Ha ha! Good eye sir! It is as I bought it, totally uncleaned and unrestored. Thankfully it is also not been worked on.
HBrown
Active Member
Ok- I'm getting back into this 2270. I had put it aside for awhile to work on my 4300. Now I have got the correct volume pot in good condition- fixing to install it. Thanks to rBuckner for the pics of the volume control and power supply parts subs! I plan on replacing H809 & H810 (2SC1213) with KSC2383YTA and for C807 I found a Nichicon PW(M) 220 uF, 25V in my parts bin. This cap should be fine right? If not, I have a Silmic II of the same specs I could use. This unit was missing H809 & H810 when I got it. After it was mentioned to maybe replace C807 I looked at it, and it did look kind of hinky so I'm going to swap it out. All this kinda suggests that there may be problems downstream of the power supply- so I'm gonna put these transistors and cap in there and then go real easy with the dbt and see what happens. Anybody got any warnings or anything else I ought to do before trying this? Thanks.
HBrown
Active Member
Got it!!
Hey- went ahead and made the repairs above- came out great! Brought it up on the dbt first, got proper bright then dim behavior, & relay click. Relay pull-in was not very authoritative- kinda lazy- but it does pull in. I need to figure that out- I reckon rebuild the rest of the power supply. Gonna check amp board health tomorrow- nothing was getting hot so I didn't bother right now. Same behavior on line voltage. Volume pot repair is good- no issues with it other than being a PITA working in that hole. Got sound- actually very good sound. I see why these 2270's are so popular- this damn thing sounds Great- and it's all old original parts- not recapped or anything. FM reception is pretty darn good too. I still have lots to do to this unit- got a few dial lights out- FM stereo indicator is out and one meter bulb is out. Want to replace vellum. And need to do some serious cleaning on the top side of the boards. I'm definately going to do some recapping also. Thanks guys for pointing me in the right direction. I was expecting the worst with this one- but it appears to be ok now other than being dirty, some light corrosion, and somewhat neglected. I wish it was in a bit better overall shape- but I got it very reasonable so I'm not complaining.
Hey- went ahead and made the repairs above- came out great! Brought it up on the dbt first, got proper bright then dim behavior, & relay click. Relay pull-in was not very authoritative- kinda lazy- but it does pull in. I need to figure that out- I reckon rebuild the rest of the power supply. Gonna check amp board health tomorrow- nothing was getting hot so I didn't bother right now. Same behavior on line voltage. Volume pot repair is good- no issues with it other than being a PITA working in that hole. Got sound- actually very good sound. I see why these 2270's are so popular- this damn thing sounds Great- and it's all old original parts- not recapped or anything. FM reception is pretty darn good too. I still have lots to do to this unit- got a few dial lights out- FM stereo indicator is out and one meter bulb is out. Want to replace vellum. And need to do some serious cleaning on the top side of the boards. I'm definately going to do some recapping also. Thanks guys for pointing me in the right direction. I was expecting the worst with this one- but it appears to be ok now other than being dirty, some light corrosion, and somewhat neglected. I wish it was in a bit better overall shape- but I got it very reasonable so I'm not complaining.
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cortico
Active Member
KutzlerTrans
Jennie & I with Buddy and Barney.
I am impressed that RB noticed the missing transistors on the PS board. Why were they missing?
Excellent pictures by Randy. for the betterment for us all, name that Camera!
As BK said, You have a rare unit.
It can be cleaned up to look like new. The frame can be dipped in Muriatic acid and clearcoated. It only takes a half a minute to remove the corrosion. That stuff is Wicked, But that frame will look beautiful!
.Its a real early unit at 3600.
Excellent pictures by Randy. for the betterment for us all, name that Camera!
As BK said, You have a rare unit.
It can be cleaned up to look like new. The frame can be dipped in Muriatic acid and clearcoated. It only takes a half a minute to remove the corrosion. That stuff is Wicked, But that frame will look beautiful!
.Its a real early unit at 3600.