John Deere AM137667 components identification .

[petehall347]

what are these black things to the right of the ic chip . ? both test as shorted .

[SMDFlea]

Re: components identification .

The one on the left could be an ON semi 1SMB26AT3 ,marking ME https://cdn.badcaps-static.com/pdfs/...70e6d21d8e.pdf

[lotas]

Re: components identification .

S2g-13-f

[petehall347]

Re: components identification .

The one on the left could be an ON semi 1SMB26AT3 ,marking ME https://cdn.badcaps-static.com/pdfs/...70e6d21d8e.pdf

i found ME marking as an inductor .. will see if it measures any inductance .

[petehall347]

Re: components identification .

ok i only just thought to look on the board for same marked components and found the same S2g one and it measures as a diode on the board . i need to remove it to know for sure .
that leaves the other one marked ME . it doesn't measure any inductance so this might well be a shorted tvs diode as suspected .
will see what pins it connects to on the ic chip if any .

[SMDFlea]

Re: components identification .

ok i only just thought to look on the board for same marked components and found the same S2g one and it measures as a diode on the board . i need to remove it to know for sure .
that leaves the other one marked ME . it doesn't measure any inductance so this might well be a shorted tvs diode as suspected .
will see what pins it connects to on the ic chip if any .

I`m fairly sure its a TVS diode connected to the high side driver chip VND5050K https://cdn.badcaps-static.com/pdfs/...5759eb738e.pdf

3.2 Load dump protection
D ld is necessary (Voltage Transient Suppressor) if the load dump peak voltage exceeds the
V CC max DC rating. The same applies if the device is subject to transients on the V CC line
that are greater than the ones shown in the ISO 7637-2: 2004(E) table.

[petehall347]

Re: components identification .

it doesn't seen to connect to that ic . i do know these are wired in series .. here is a pic with them removed . and yes i spotted the broke trace ..where the pass through is .. right where they join together .

[sam_sam_sam]

Re: components identification .

To me this board looks like shit with all of what looks like flux

What is the description of the device

[petehall347]

Re: components identification .

To me this board looks like shit with all of what looks like flux

What is the description of the device

the stuff is potting compound shit . took ages getting it as clean as it is .. its a control box for john deere garden tractor . box id ..AM137667

[stj]

Re: components identification .

what does it actually do?

[petehall347]

Re: components identification .

what does it actually do?

main thing it does is short the ignition coils when ignition is off . also it controls things like the pto but only if interlock safety switches are switched on such as seat switch and brake etc . the older tractors just had relays and safety switches .the more modern ones have these silly boxes to switch the odd relay . some older ones than this i have fixed by simply replacing relay drive transistors or patching traces when the battery has been connected backwards .
these particular boxes seem to have a large fail rate and it would be good to find and fix whatever the weak spots are .

[sam_sam_sam]

Re: components identification .

Why not do away with the this controller board and do like older version does it sense it only controller the PTO and ground the ignition coils when ignition is off make it simple to use and operate

[petehall347]

Re: components identification .

Why not do away with the this controller board and do like older version does it sense it only controller the PTO and ground the ignition coils when ignition is off make it simple to use and operate

because the person wanting it done will be selling it and its lots easier to deal with this controller unit than redesigning and wiring the whole machine which would cost more than a new controller . oh yes it also does the hours counter so that would need to be sorted as well .

[petehall347]

Re: components identification .

now i have a problem finding the parts . RS dont appear to have them and none on ebay in this country . . are there any suitable subs ? https://uk.rs-online.com/web/zr/?sea...d%22%3Atrue%7D

[petehall347]

Re: components identification .

does this look right one for 1SMB26AT3 ? https://uk.rs-online.com/web/p/tvs-diodes/8062019

[petehall347]

Re: components identification .

does this look right for the other one ? https://uk.rs-online.com/web/p/schot...fiers/6291426/

[petehall347]

Re: components identification .

bump

[petehall347]

are these the correct ones .

1SMB26AT3,,,
https://uk.rs-online.com/web/p/tvs-diodes/8062019

S2g-13-f...
https://uk.rs-online.com/web/p/schot...fiers/6291426/

i do have a thread running but not getting replies . i could do with getting these ordered .

[petehall347]

Re: components identification .

have ordered those parts anyway just in case i chose the correct ones .

[petehall347]

Re: John Deere AM137667 components identification .

soldered parts in .. fingers crossed it will now work ..
new parts aren't marked quite the same as originals .