Thank you ! I was thinking this was it ! This was a new to me radio and was not retaining memory. It had a 100uF cap in it's place must've been a recap error. Replaced it with proper one and all is well now !!I believe this is what it is you're looking for. A 1000uf electrolytic and is on the back of the CPU board, basically a general purpose cap. I try and use 105C as much possible although it may be overkill as 85C are about 185F.
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Original value was 100uf.
Lame.
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Not trying to stir a fight. I replaced the 100uf with a 1000uf as my post replay suggested and my memory was restored as it was. So a simple fix for me. great site that always has the answers. Thank you Smokinone.... I am about to do the same ! This cap is C4 on the CPU board that this thread is aboutI don't know as there are a few variations of this orange display version that were made. The 2950 I just recapped had all the original caps in place and it was a 1000uf, 10V.
Most of the orange display 2950"s I have had were of the battery type, this one I just re-capped is the first I've had with the cap memory.
Not looking for an argument, just sayin what was in mine. The service manual I have doesn't show it, but it shows the R611 I believe it is, that can be changed out to stabilize the channel change or encoder operation. This 2950 with the cap memory doesn't have that resistor that I can see, which is also on the CPU board...on some.
These manufacturers change parts and values all the time so it's hard to say what's in em. They don't usually tell us unless a service bulletin comes out...which I haven't seen in a while like some of the older radios like Cobra and Realistic etc.
Thanks
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Ok I'll check thank you NomadradioLook beneath connector CN604. It's peeking out from under the row of header plugs.
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Does it store the information in volatile memory until the radio is turned off? Maybe the charge in that capacitor is to write to the eeprom after the radio is turned off so it only writes once per power cycle.The schematic makes it appear that C4 does this job in the DX radio's computer board. Capacitance is 220uf. Should be the biggest one on the board. Never have figured out just why they stick with this method. The board has a 93LC46 chip. It's a non-volatile EEROM chip. Seemed to me this would take the place of a stored-voltage keep-alive for the volatile RAM in the radio's CPU.
Maybe they worried that storing every click of the tuning knob would wear it out. EEROM memories have a finite number of write/erase cycles before they wear out. Can't see any other reason why they didn't just use that chip and lose the capacitor.
Be nice to that pc board. You'll need a light touch to remove that cap without damaging the metal sleeve "plate-through" inside the holes where it's mounted.
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thank youDoes it store the information in volatile memory until the radio is turned off? Maybe the charge in that capacitor is to write to the eeprom after the radio is turned off so it only writes once per power cycle.
I was asking, not sure if that's what it actually does. Nomad made it sound like that would have to be the case to not wear out the eeprom. Makes sense anyhow.thank you