Mike
The voltage loss is due to a bad via on the board.? You jumpers it the same way that I’ve done it.
The old part number for that IC is a 2502-4.? The revised part number is a TLP542 or similar.? I’ve used several different ICs of that same numbering range.? I can look tomorrow- I may have one in the garage I can send you.
Dennis W1UE
Update on Low audio:
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From my good friend WD8DSB:
Today Mike (W9RE) and I did some troubleshooting on a YCCC SO2R box at Mike’s and found we had lost 5 Vdc on pins 11 and 15 on the MAX9722A but we had 5Vdc on pins 2 and 3. We then did continuity checks and saw something like 3 Meg Ohms between pin 2 and 15 as an example. We decided we must have had a broken trace so we installed a jumper between C104 and C107 pins that normally have 5Vdc to reestablish 5 Vdc on pins 11 and 15 and this fixed the original problem of no audio output.
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BTW my box has a white DIP for U3 where my spare (just repaired box) has a black DIP for U3.? I am not using Icom rigs right now but should I replace it anyway?? If so what part number should I order?
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Thanks,
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Mike W9RE
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I obtained? a spare (backup) SO2R Box+ and comparing it to my original unit I notice that the audio is say a good 6db lower when listening to radio 1 when plugged into either channel 1 or channel 2.? This is only with the radio plugged into either DIN,? 12Vdc and audio out plugged in and of course flipping the rx switch.
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Any things I should check or buy for replacing??
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Paul was there a chip that was universally replaced in the original buy?? I think the vintage of both units is the same.? Seems like I remember something about a green or white device that should be replaced (updated)?
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Tnx,
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Mike W9RE
