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First Marshall use of PbF ? / Test for PbF

Just found 4 PbF faults on a 2003 AS50R, no mention of RoHS/PbF on the pcb as pre-2006. Distortion after an hour of normal use Appearance probably but not definitively PbF, shallow cones rather than domes but no pastey/crackle-finish or white blotchiness. Anyone have any precise knowledge about their first using date?

I'm thinking of using my never used thermocouple monitored variable temp OK soldering iron set up for a tester, if it will go that low.

185C/365F for SnPb and 217C/422F for production PbF seems about the temperatures. Olive oil in a heated bath (with flammability precautions in place) will go up to 210 deg C without smoking or boiling. Would adjusting down the preset range and setting the tip for 200 deg C / 400 deg F make a Go/No-go test to discriminate , as long as IC pad size solder blobs, ie little heatsinking. Anyone any input on heat-transfer/heatsinking/elevated temp requirement to differentiate the 2 types of solder ? or just suck it and see around 200 deg C with both types of definitely known pieces of solder wire off the reel
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N_Cook
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I calibrated the iron tip in an oil bath with a 250 deg C glass thermometer, to a known 200 deg C with the heater LED slow intermittent. Tried distinguishing known 60/40 leaded solder and known silver solder

95.5/4/.5 and had to drop the set point down to 188 C to melt leaded solder wire on the tip and not melt silver solder wire. More than just the test part of the tip in the oil so perhaps explains the lower set point. Swathed the tip with tallow-looking conventional solder flux over the tip to assist action. So distinguishing Pb/Sn and production PbF should be more straightforward with this "test iron" . Testing on IC/small transistor pad/joints and then by inference the same solder used in the usual suspect areas, ie larger pads, larger leads but PbF not up to the job.
Reply to
N_Cook

"N_Cook" wrote in news:ho0b67$ag9$ snipped-for-privacy@news.eternal- september.org:

....

I think I would use a hot air gun with digital temp control such as

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I have one of these and find it to be quite useful for soldering and desoldering.

You may find the following table useful:

[quote] C F 183 361.4 63/37 It has the lowest melting point (183 °C or 361.4 °F) of all the tin/lead alloys; and 220 428 SnAg3.0Cu0.5, tin with 3% silver and 0.5% copper, has a melting point of 217 to 220 °C 218 424.4 SnAg3.5Cu0.7 is another commonly used alloy, with melting point of 217-218 °C. 217 422.6 SnAg3.5Cu0.9, with melting point of 217 °C, is determined by NIST to be truly eutectic. 218 424.4 SnAg3.8Cu0.7, with melting point 217-218 °C, is preferred by the European IDEALS consortium for reflow soldering. 223 433.4 SnAg3.8Cu0.7Sb0.25 is preferred by the European IDEALS consortium for wave soldering. 32 SnAg3.9Cu0.6, with melting point 217-223 °C, is recommended by the US NEMI consortium for reflow soldering. 32 227 440.6 SnCu0.7, with melting point of 227 °C, is a cheap alternative for wave soldering, recommended by the US NEMI consortium. 199 390.2 SnZn9, with melting point of 199 °C, is a cheaper alloy but is prone to corrosion and oxidation. 198 388.4 SnZn8Bi3, with melting point of 191-198 °C, is also prone to corrosion and oxidation due to its zinc content. 240 464 SnSb5, tin with 5% of antimony, is the US plumbing industry standard. Its melting point is 232-240 °C. It displays good resistance to thermal fatigue and good shear strength. 225 437 SnAg2.5Cu0.8Sb0.5 melts at 217-225 °C and is patented by AIM alliance. 208 406.4 SnIn8.0Ag3.5Bi0.5 melts at 197 to 208 °C and is patented by Matsushita/Panasonic. 139 282.2 SnBi57Ag1 melts at 137-139 °C and is patented by Motorola. 138 280.4 SnBi58 melts at 138 °C. 118 244.4 SnIn52 melts at 118 °C and is suitable for the cases where low-temperature soldering is needed. [unquote] 
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bz    	73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an 
infinite set.
Reply to
bz

pcb

any

temp

but

by

Which would be likely most common PbF in consumer goods ? presumably the 227 °C cheap one

Reply to
N_Cook

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