2385 reconnect PS00 to P400 pin question
- Thread starter sendust
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I still think that the board layout has the JE02 pin numbers labeled backwards. I had relabeled them on my layout.
I don't know what trace you are talking about???
Everything looks like the schematic and layout in the SM (with the exception of two solder bridges along the path.
Make sure those two solder bridges are OK.
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You can find the bad trace by connecting a wire jumper from point to point to see if you get continuity back. Start at the connector JE03 and jumper to the next solder lead on the path. When you get the sound back, that's the trace you are having problems with. If it's only the R channel, there aren't too many to check.
This might help you. Either connect an Ohm meter between solder bumps, point to point, with the same number and see which gives you > 0 Ohms.
Or, with an audio signal going through both channels, use a wire jumper to connect any of the points with the same number to see which restores the audio.
This might help you. Either connect an Ohm meter between solder bumps, point to point, with the same number and see which gives you > 0 Ohms.
Or, with an audio signal going through both channels, use a wire jumper to connect any of the points with the same number to see which restores the audio.
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I used a wire and had it held on each trace to see if there was any change with the fluctuation of numbers , great idea but that was not the issue. when we started working on the RE42 we had the same issue with Right channel, At the time i reflowed all of the connections in the right path including the three pins from the RE42. What i didnt notice was that solder was flowing past the pins through the board, Those pins had been re soldered in the past before i owned the unit. Im guessing at that time some solder flowed the same way, i made it worse. Its that solder that was causing most of my issue, it was cold solder and when the board moved even slightly it would short the pins. I painstakingly cleaned out that solder as best i could. Its very hard to get in there. Now i see no more fluctuation, the only difference now is when at full volume i get 0.3 on left and 1.8 at right, this may be the volume pot because all traces tested are 0.1. How do you keep solder from flowing down through the board when the hole is a little larger than the pin, I think there use to be a round trace below the end pin.
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Since the board is single sided, and there is no copper on the component side of the board, all of your solder is wicking up the lead pin.
Your soldering job does not look good (not smooth but also "lumpy") and looks like a cold solder joint.
- To clean this out you first need to completely remove all of the solder from the board pad and the volume control pin with solder braid or solder sucker.
- Next, you need to clean both the board pad and component lead with Isopropyl alcohol. If needed, use a clean small stiff brush to remove old flux from the board.
- The pad and lead should now look shiny.
- Apply a small amount of either paste or pen solder flux to the board and lead. This is important because the old solder, board and lead may be oxidized and the flux will clean it for the new solder.
- With your soldering iron tip temperature set to 350C to 360C degrees, touch the tip to both the pad and lead simultaneously.
- Allow it to heat for a few seconds then apply the solder to the joint and quickly feed it until the lead is fully attached to the board.
- Too much solder or a cold tip will not make a smooth, clean looking joint. If it looks "lumpy", then not enough heat applied to the joint.
- Remove the iron tip and let it cool. The solder should look bright, shiny, and smooth... and not a "blob" of solder.
- If you heat both the board pad and lead at the same time, solder should not flow up the lead to the other side of the board.
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I removed the solder from the three outer pins, cleaned with alcohol, used fine brass brush, let dry, applied solder paste, set weller to 360 C touched pin to heat, waited a few seconds, touched top of pin to make sure pin was melting solder, solder ran down pin to underside of board. Either the openings are to big or maybe i have the wrong solder.
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I guess that you can try to stand the board on end so the solder does not flow through the hole?
You could try soldering one side of the pin to the pad first, let it cool down, then heat up the other side and apply solder to the other side of the pad and pin.
The first bit of solder will partially block the hole so all of the solder does not go through the hole.
Another thought is that you could wrap some bare wire around the pin a few turns so when you apply the solder it will adhere to the wrapped wire also and electrically connect the pad to the wire and pin.
You could try soldering one side of the pin to the pad first, let it cool down, then heat up the other side and apply solder to the other side of the pad and pin.
The first bit of solder will partially block the hole so all of the solder does not go through the hole.
Another thought is that you could wrap some bare wire around the pin a few turns so when you apply the solder it will adhere to the wrapped wire also and electrically connect the pad to the wire and pin.
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I cleaned all of the solder of the pins, used alcohol and paste, positioned the board on its side, soldered the pins just half, turned board over and soldered other half, no solder seeped down the board, all readings are now proper and the same. reattached board and used a jumper instead of the PS00, right side was clear and strong, but left now intermittent, i figure a wire must have broken but not come off. While looking for this issue something strange has taken place, with selector on AM or FM red led lights up and i get sound, on phono 1,2 and aux, no red light and no sound. Can a bad connection do this and would the connection be on the P400 board ? Or is that a switch issue?
I dont have that board connected, i was going to use the jumpers until everything is resolved. From what i see here i dont know why i would loose those three inputs, i can see an issue if a wire was off to loose the LED but how can i loose the imputs, or am i only getting sound from AM FM and not any other imput.
Here is the wiring from the LEDs to the selector switch.
- You can see that the AM goes through J410
- FM goes through J418
- PH1, PH2, Aux go through J408.
- What is common for all three sources that don't work is that they all go through connector J408. AM & FM go through different connectors.
- These are not the audio paths, only for the lights.
To isolate the problem you need to swap the input to PHONO 2 and see if it is the same.
What about the AUX input, Tape 1 and Tape 2? Do they work OK.
If Tape 1 In and Tape 2 In work OK, then the problem is in the P400 board, connectors to the PS00 board, or connectors to the Phono 1, 2, Aux input jacks.
I thought some of the LEDs were burnt out, now i find i cant test LEDs on diode, live and learn. On connector 406 there is only one wire and i see it has been soldered ,so repaired in the past. That one wire is on pin 1, is that correct or should it be in the center ?
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